Linux文本处理工具
Linux文本处理工具
作者：尹正杰
版权声明：原创作品，谢绝转载！否则将追究法律责任。
一.文本文件查看相关命令
1>.查看cat命令的帮助信息
[root@node101.yinzhengjie.org.cn ~]# cat --help Usage: cat [OPTION]... [FILE]... Concatenate FILE(s), or standard input, to standard output. -A, --show-all equivalent to -vET -b, --number-nonblank number nonempty output lines, overrides -n -e equivalent to -vE -E, --show-ends display $ at end of each line -n, --number number all output lines -s, --squeeze-blank suppress repeated empty output lines -t equivalent to -vT -T, --show-tabs display TAB characters as ^I -u (ignored) -v, --show-nonprinting use ^ and M- notation, except for LFD and TAB --help display this help and exit --version output version information and exit With no FILE, or when FILE is -, read standard input. Examples: cat f - g Output f's contents, then standard input, then g's contents. cat Copy standard input to standard output. GNU coreutils online help: <http://www.gnu.org/software/coreutils/> For complete documentation, run: info coreutils 'cat invocation' [root@node101.yinzhengjie.org.cn ~]#
2>.cat命令常用参数
[root@node101.yinzhengjie.org.cn ~]# cat f1.txt 1 2 3 4 5 [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# cat -n f1.txt #对文件原每行内容加行号 1 1 2 3 2 4 5 3 6 4 7 8 5 [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# cat f1.txt 1 2 3 4 5 [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# cat -n f1.txt 1 1 2 3 2 4 5 3 6 4 7 8 5 [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# cat -b f1.txt #和"-n"参数想必，"-b"对空白字符就不加行号,这是两者对区别。 1 1 2 2 3 3 4 4 5 5 [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# cat -n f1.txt 1 1 2 3 2 4 5 6 7 3 8 4 9 10 5 [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# cat -sn f1.txt #通过对比可以发现，"-s"具有将相邻空行压缩成一行输出的功能。 1 1 2 3 2 4 5 3 6 4 7 8 5 [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# cat f1.txt 1 2 a b 3 4 5 [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# cat -A f1.txt #显示所有控制符。 1$ #注意，"$"表示换行，类似于Linux的换行符"\n"。 $ 2^Ia^Ib$ #注意，"^I"表示tab键 $ $ $ 3$ 4$ $ 5$ [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# vi f1.txt #在命令模式中执行":set ff=dos"就可以将Linux操作系统的格式指定为dos格式。 [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# cat -A f1.txt 1^M$ #注意，"^M"表示回车，"$"表示换行，合起来类似于windows的换行符"\r\n"。 ^M$ 2^Ia^Ib^M$ ^M$ ^M$ ^M$ 3^M$ 4^M$ ^M$ 5^M$ [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# cat f1.txt 1 2 a b 3 4 5 [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# cat -E f1.txt #显示行结束符"$" $ $ $ a b $ $ $ $ $ $ $ [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]#
3>.使用nl命令也可以查看行号
[root@node101.yinzhengjie.org.cn ~]# cat f1.txt 1 2 a b 3 4 5 [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# nl f1.txt #为nl命令添加行号，效果和"cat -n f1.txt"功能等效。 1 1 2 3 2 a b 4 5 6 7 3 8 4 9 10 5 [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# cat -n f1.txt 1 1 2 3 2 a b 4 5 6 7 3 8 4 9 10 5 [root@node101.yinzhengjie.org.cn ~]#
4>.使用tac命令倒着查看文件内容
[root@node101.yinzhengjie.org.cn ~]# cat f1.txt 1 2 a b 3 4 5 [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# tac f1.txt #和"cat"命令都是查看文件内容，只不过它和cat查看内容的起始点不同，"tac"从最后一行到第一行去查看文件内容。但每行内容不变！ 5 4 3 2 a b 1 [root@node101.yinzhengjie.org.cn ~]#
5>.使用rev命令将每行内容倒着看
[root@node101.yinzhengjie.org.cn ~]# echo abcdefg | rev #rev命令可以将内容标准输入但数据倒着输出 gfedcba [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# cat f1.txt 1 2 a b 3 4 5 [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# rev f1.txt #很明显，"rev"命令可以将每行内容倒着查看。 1 b a 2 3 4 5 [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]#
二.查看非文本文件内容
1>.hexdump命令
[root@node101.yinzhengjie.org.cn ~]# hexdump --help #查看该命令的帮助信息 hexdump: invalid option -- '-' Usage: hexdump [options] file... Options: -b one-byte octal display -c one-byte character display -C canonical hex+ASCII display -d two-byte decimal display -o two-byte octal display -x two-byte hexadecimal display -e format format string to be used for displaying data -f format_file file that contains format strings -n length interpret only length bytes of input -s offset skip offset bytes from the beginning -v display without squeezing similar lines -V output version information and exit [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# hexdump -C -n 512 /dev/sda #我们知道使用cat命令查看块设备"/dev/sda"会出现乱码字符，我们这里的"=C"表示以标准十六进制和ASCII显示该设备文件内容，-n表示查看该文件的长度。 00000000 eb 63 90 10 8e d0 bc 00 b0 b8 00 00 8e d8 8e c0 |.c..............| 00000010 fb be 00 7c bf 00 06 b9 00 02 f3 a4 ea 21 06 00 |...|.........!..| 00000020 00 be be 07 38 04 75 0b 83 c6 10 81 fe fe 07 75 |....8.u........u| 00000030 f3 eb 16 b4 02 b0 01 bb 00 7c b2 80 8a 74 01 8b |.........|...t..| 00000040 4c 02 cd 13 ea 00 7c 00 00 eb fe 00 00 00 00 00 |L.....|.........| 00000050 00 00 00 00 00 00 00 00 00 00 00 80 01 00 00 00 |................| 00000060 00 00 00 00 ff fa 90 90 f6 c2 80 74 05 f6 c2 70 |...........t...p| 00000070 74 02 b2 80 ea 79 7c 00 00 31 c0 8e d8 8e d0 bc |t....y|..1......| 00000080 00 20 fb a0 64 7c 3c ff 74 02 88 c2 52 be 05 7c |. ..d|<.t...R..|| 00000090 b4 41 bb aa 55 cd 13 5a 52 72 3d 81 fb 55 aa 75 |.A..U..ZRr=..U.u| 000000a0 37 83 e1 01 74 32 31 c0 89 44 04 40 88 44 ff 89 |7...t21..D.@.D..| 000000b0 44 02 c7 04 10 00 66 8b 1e 5c 7c 66 89 5c 08 66 |D.....f..\|f.\.f| 000000c0 8b 1e 60 7c 66 89 5c 0c c7 44 06 00 70 b4 42 cd |..`|f.\..D..p.B.| 000000d0 13 72 05 bb 00 70 eb 76 b4 08 cd 13 73 0d 5a 84 |.r...p.v....s.Z.| 000000e0 d2 0f 83 de 00 be 85 7d e9 82 00 66 0f b6 c6 88 |.......}...f....| 000000f0 64 ff 40 66 89 44 04 0f b6 d1 c1 e2 02 88 e8 88 |d.@f.D..........| 00000100 f4 40 89 44 08 0f b6 c2 c0 e8 02 66 89 04 66 a1 |.@.D.......f..f.| 00000110 60 7c 66 09 c0 75 4e 66 a1 5c 7c 66 31 d2 66 f7 |`|f..uNf.\|f1.f.| 00000120 34 88 d1 31 d2 66 f7 74 04 3b 44 08 7d 37 fe c1 |4..1.f.t.;D.}7..| 00000130 88 c5 30 c0 c1 e8 02 08 c1 88 d0 5a 88 c6 bb 00 |..0........Z....| 00000140 70 8e c3 31 db b8 01 02 cd 13 72 1e 8c c3 60 1e |p..1......r...`.| 00000150 b9 00 01 8e db 31 f6 bf 00 80 8e c6 fc f3 a5 1f |.....1..........| 00000160 61 ff 26 5a 7c be 80 7d eb 03 be 8f 7d e8 34 00 |a.&Z|..}....}.4.| 00000170 be 94 7d e8 2e 00 cd 18 eb fe 47 52 55 42 20 00 |..}.......GRUB .| 00000180 47 65 6f 6d 00 48 61 72 64 20 44 69 73 6b 00 52 |Geom.Hard Disk.R| 00000190 65 61 64 00 20 45 72 72 6f 72 0d 0a 00 bb 01 00 |ead. Error......| 000001a0 b4 0e cd 10 ac 3c 00 75 f4 c3 00 00 00 00 00 00 |.....<.u........| 000001b0 00 00 00 00 00 00 00 00 7c 37 0e 00 00 00 80 20 |........|7..... | 000001c0 21 00 83 dd 1e 3f 00 08 00 00 00 a0 0f 00 00 dd |!....?..........| 000001d0 1f 3f 8e fe ff ff 00 a8 0f 00 00 58 f0 07 00 00 |.?.........X....| 000001e0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| 000001f0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 55 aa |..............U.| 00000200 [root@node101.yinzhengjie.org.cn ~]#
2>.od命令（用于将文件以八进制或者其他进制显示）
[root@node101.yinzhengjie.org.cn ~]# od --help #查看该命令的帮助信息 Usage: od [OPTION]... [FILE]... or: od [-abcdfilosx]... [FILE] [[+]OFFSET[.][b]] or: od --traditional [OPTION]... [FILE] [[+]OFFSET[.][b] [+][LABEL][.][b]] Write an unambiguous representation, octal bytes by default, of FILE to standard output. With more than one FILE argument, concatenate them in the listed order to form the input. With no FILE, or when FILE is -, read standard input. If first and second call formats both apply, the second format is assumed if the last operand begins with + or (if there are 2 operands) a digit. An OFFSET operand means -j OFFSET. LABEL is the pseudo-address at first byte printed, incremented when dump is progressing. For OFFSET and LABEL, a 0x or 0X prefix indicates hexadecimal; suffixes may be . for octal and b for multiply by 512. Mandatory arguments to long options are mandatory for short options too. -A, --address-radix=RADIX output format for file offsets; RADIX is one of [doxn], for Decimal, Octal, Hex or None -j, --skip-bytes=BYTES skip BYTES input bytes first -N, --read-bytes=BYTES limit dump to BYTES input bytes -S BYTES, --strings[=BYTES] output strings of at least BYTES graphic chars; 3 is implied when BYTES is not specified -t, --format=TYPE select output format or formats -v, --output-duplicates do not use * to mark line suppression -w[BYTES], --width[=BYTES] output BYTES bytes per output line; 32 is implied when BYTES is not specified --traditional accept arguments in third form above --help display this help and exit --version output version information and exit Traditional format specifications may be intermixed; they accumulate: -a same as -t a, select named characters, ignoring high-order bit -b same as -t o1, select octal bytes -c same as -t c, select printable characters or backslash escapes -d same as -t u2, select unsigned decimal 2-byte units -f same as -t fF, select floats -i same as -t dI, select decimal ints -l same as -t dL, select decimal longs -o same as -t o2, select octal 2-byte units -s same as -t d2, select decimal 2-byte units -x same as -t x2, select hexadecimal 2-byte units TYPE is made up of one or more of these specifications: a named character, ignoring high-order bit c printable character or backslash escape d[SIZE] signed decimal, SIZE bytes per integer f[SIZE] floating point, SIZE bytes per integer o[SIZE] octal, SIZE bytes per integer u[SIZE] unsigned decimal, SIZE bytes per integer x[SIZE] hexadecimal, SIZE bytes per integer SIZE is a number. For TYPE in [doux], SIZE may also be C for sizeof(char), S for sizeof(short), I for sizeof(int) or L for sizeof(long). If TYPE is f, SIZE may also be F for sizeof(float), D for sizeof(double) or L for sizeof(long double). Adding a z suffix to any type displays printable characters at the end of each output line. BYTES is hex with 0x or 0X prefix, and may have a multiplier suffix: b 512 KB 1000 K 1024 MB 1000*1000 M 1024*1024 and so on for G, T, P, E, Z, Y. GNU coreutils online help: <http://www.gnu.org/software/coreutils/> For complete documentation, run: info coreutils 'od invocation' [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# echo {a..z} a b c d e f g h i j k l m n o p q r s t u v w x y z [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# echo {a..z} | tr -d ' ' abcdefghijklmnopqrstuvwxyz [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# echo {a..z} | tr -d ' ' | od -A x -t x1z 000000 61 62 63 64 65 66 67 68 69 6a 6b 6c 6d 6e 6f 70 >abcdefghijklmnop< 000010 71 72 73 74 75 76 77 78 79 7a 0a >qrstuvwxyz.< 00001b [root@node101.yinzhengjie.org.cn ~]#
3>.xxd命令
[root@node101.yinzhengjie.org.cn ~]# yum whatprovides xxd #使用yum命令检查xxd模块由那个模块提供 Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile * base: mirrors.tuna.tsinghua.edu.cn * extras: mirrors.tuna.tsinghua.edu.cn * updates: mirrors.tuna.tsinghua.edu.cn base/7/x86_64/filelists_db | 7.3 MB 00:00:00 extras/7/x86_64/filelists_db | 207 kB 00:00:00 updates/7/x86_64/filelists_db | 1.4 MB 00:00:00 2:vim-common-7.4.629-6.el7.x86_64 : The common files needed by any version of the VIM editor Repo : base Matched from: Filename : /usr/bin/xxd [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# yum -y install vim-common-7.4.629-6.el7.x86_64 #根据上条命令查看到xxd依赖于该安装包，安装后就可以使用xxd命令啦 Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile * base: mirrors.tuna.tsinghua.edu.cn * extras: mirrors.tuna.tsinghua.edu.cn * updates: mirrors.tuna.tsinghua.edu.cn Resolving Dependencies --> Running transaction check ---> Package vim-common.x86_64 2:7.4.629-6.el7 will be installed --> Processing Dependency: vim-filesystem for package: 2:vim-common-7.4.629-6.el7.x86_64 --> Running transaction check ---> Package vim-filesystem.x86_64 2:7.4.629-6.el7 will be installed --> Finished Dependency Resolution Dependencies Resolved ============================================================================================================================================================================= Package Arch Version Repository Size ============================================================================================================================================================================= Installing: vim-common x86_64 2:7.4.629-6.el7 base 5.9 M Installing for dependencies: vim-filesystem x86_64 2:7.4.629-6.el7 base 11 k Transaction Summary ============================================================================================================================================================================= Install 1 Package (+1 Dependent package) Total download size: 5.9 M Installed size: 21 M Downloading packages: (1/2): vim-filesystem-7.4.629-6.el7.x86_64.rpm | 11 kB 00:00:00 (2/2): vim-common-7.4.629-6.el7.x86_64.rpm | 5.9 MB 00:00:00 ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Total 8.3 MB/s | 5.9 MB 00:00:00 Running transaction check Running transaction test Transaction test succeeded Running transaction Installing : 2:vim-filesystem-7.4.629-6.el7.x86_64 1/2 Installing : 2:vim-common-7.4.629-6.el7.x86_64 2/2 Verifying : 2:vim-common-7.4.629-6.el7.x86_64 1/2 Verifying : 2:vim-filesystem-7.4.629-6.el7.x86_64 2/2 Installed: vim-common.x86_64 2:7.4.629-6.el7 Dependency Installed: vim-filesystem.x86_64 2:7.4.629-6.el7 Complete! [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# xxd --help #查看该命令的帮助信息 Usage: xxd [options] [infile [outfile]] or xxd -r [-s [-]offset] [-c cols] [-ps] [infile [outfile]] Options: -a toggle autoskip: A single '*' replaces nul-lines. Default off. -b binary digit dump (incompatible with -ps,-i,-r). Default hex. -c cols format <cols> octets per line. Default 16 (-i: 12, -ps: 30). -E show characters in EBCDIC. Default ASCII. -g number of octets per group in normal output. Default 2. -h print this summary. -i output in C include file style. -l len stop after <len> octets. -ps output in postscript plain hexdump style. -r reverse operation: convert (or patch) hexdump into binary. -r -s off revert with <off> added to file positions found in hexdump. -s [+][-]seek start at <seek> bytes abs. (or +: rel.) infile offset. -u use upper case hex letters. -v show version: "xxd V1.10 27oct98 by Juergen Weigert". [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# echo {a..z} a b c d e f g h i j k l m n o p q r s t u v w x y z [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# echo {a..z} | tr -d ' ' #将空格删除 abcdefghijklmnopqrstuvwxyz [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# echo {a..z} | tr -d ' ' | xxd #默认以十六进制显示相应内容 0000000: 6162 6364 6566 6768 696a 6b6c 6d6e 6f70 abcdefghijklmnop 0000010: 7172 7374 7576 7778 797a 0a qrstuvwxyz. [root@node101.yinzhengjie.org.cn ~]#
三.分页查看文本文件内容
1>.more命令用于分页查看文件
[root@node101.yinzhengjie.org.cn ~]# more #默认显示more命令的帮助信息 Usage: more [options] file... Options: -d display help instead of ring bell -f count logical, rather than screen lines -l suppress pause after form feed -p do not scroll, clean screen and display text -c do not scroll, display text and clean line ends -u suppress underlining -s squeeze multiple blank lines into one -NUM specify the number of lines per screenful +NUM display file beginning from line number NUM +/STRING display file beginning from search string match -V output version information and exit [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# more /var/log/messages #查看系统日志文件内容，由于内容过多，一屏幕无法全部显示输出，因此会分页显示且最后一行会有一个进度条 Sep 8 03:41:01 node101 rsyslogd: [origin software="rsyslogd" swVersion="8.24.0-34.el7" x-pid="4104" x-info="http://www.rsyslog.com"] rsyslogd was HUPed Sep 8 04:01:01 node101 systemd: Started Session 31 of user root. Sep 8 05:01:01 node101 systemd: Started Session 32 of user root. Sep 8 06:01:01 node101 systemd: Started Session 33 of user root. Sep 8 07:01:01 node101 systemd: Started Session 34 of user root. Sep 8 08:01:01 node101 systemd: Started Session 35 of user root. Sep 8 08:15:17 node101 chronyd[3566]: Source 193.228.143.12 replaced with 124.108.20.1 Sep 8 09:01:01 node101 systemd: Started Session 36 of user root. Sep 8 10:01:01 node101 systemd: Started Session 37 of user root. Sep 8 11:01:01 node101 systemd: Started Session 38 of user root. Sep 8 12:01:01 node101 systemd: Started Session 39 of user root. Sep 8 13:00:23 node101 chronyd[3566]: Can't synchronise: no selectable sources Sep 8 13:01:01 node101 systemd: Started Session 40 of user root. Sep 8 14:01:01 node101 systemd: Started Session 41 of user root. Sep 8 15:01:01 node101 systemd: Started Session 42 of user root. Sep 8 16:01:01 node101 systemd: Started Session 43 of user root. Sep 8 17:01:02 node101 systemd: Started Session 44 of user root. Sep 8 18:01:01 node101 systemd: Started Session 45 of user root. Sep 8 18:10:15 node101 chronyd[3566]: Selected source 45.43.30.59 Sep 8 18:36:16 node101 chronyd[3566]: Source 124.108.20.1 replaced with 139.199.214.202 Sep 8 19:01:01 node101 systemd: Started Session 46 of user root. Sep 8 20:01:01 node101 systemd: Started Session 47 of user root. Sep 8 20:37:06 node101 chronyd[3566]: Selected source 139.199.214.202 Sep 8 20:58:19 node101 systemd-logind: Removed session 1. Sep 8 20:58:19 node101 systemd: Removed slice User Slice of root. Sep 8 21:01:01 node101 systemd: Created slice User Slice of root. Sep 8 21:01:01 node101 systemd: Started Session 48 of user root. Sep 8 21:01:01 node101 systemd: Removed slice User Slice of root. Sep 8 22:01:01 node101 systemd: Created slice User Slice of root. Sep 8 22:01:01 node101 systemd: Started Session 49 of user root. Sep 8 22:01:01 node101 systemd: Removed slice User Slice of root. Sep 8 23:01:01 node101 systemd: Created slice User Slice of root. Sep 8 23:01:01 node101 systemd: Started Session 50 of user root. Sep 8 23:01:01 node101 systemd: Removed slice User Slice of root. Sep 8 23:04:18 node101 systemd: Starting Cleanup of Temporary Directories... Sep 8 23:04:18 node101 systemd: Started Cleanup of Temporary Directories. Sep 8 23:51:00 node101 systemd: Created slice User Slice of root. Sep 8 23:51:00 node101 systemd-logind: New session 51 of user root. Sep 8 23:51:00 node101 systemd: Started Session 51 of user root. Sep 9 00:01:01 node101 systemd: Started Session 52 of user root. Sep 9 01:01:02 node101 systemd: Started Session 53 of user root. Sep 9 01:06:52 node101 NetworkManager[3613]: <info> [1568005612.4339] device (eth0): carrier: link connected Sep 9 02:00:03 node101 systemd-logind: Removed session 51. Sep 9 02:00:03 node101 systemd: Removed slice User Slice of root. --More--(2%)
[root@node101.yinzhengjie.org.cn ~]# more -d /var/log/messages #注意最后一行，除了显示当前页在占该文件的百分比外，还会有一个退出提示 Sep 8 03:41:01 node101 rsyslogd: [origin software="rsyslogd" swVersion="8.24.0-34.el7" x-pid="4104" x-info="http://www.rsyslog.com"] rsyslogd was HUPed Sep 8 04:01:01 node101 systemd: Started Session 31 of user root. Sep 8 05:01:01 node101 systemd: Started Session 32 of user root. Sep 8 06:01:01 node101 systemd: Started Session 33 of user root. Sep 8 07:01:01 node101 systemd: Started Session 34 of user root. Sep 8 08:01:01 node101 systemd: Started Session 35 of user root. Sep 8 08:15:17 node101 chronyd[3566]: Source 193.228.143.12 replaced with 124.108.20.1 Sep 8 09:01:01 node101 systemd: Started Session 36 of user root. Sep 8 10:01:01 node101 systemd: Started Session 37 of user root. Sep 8 11:01:01 node101 systemd: Started Session 38 of user root. Sep 8 12:01:01 node101 systemd: Started Session 39 of user root. Sep 8 13:00:23 node101 chronyd[3566]: Can't synchronise: no selectable sources Sep 8 13:01:01 node101 systemd: Started Session 40 of user root. Sep 8 14:01:01 node101 systemd: Started Session 41 of user root. Sep 8 15:01:01 node101 systemd: Started Session 42 of user root. Sep 8 16:01:01 node101 systemd: Started Session 43 of user root. Sep 8 17:01:02 node101 systemd: Started Session 44 of user root. Sep 8 18:01:01 node101 systemd: Started Session 45 of user root. Sep 8 18:10:15 node101 chronyd[3566]: Selected source 45.43.30.59 Sep 8 18:36:16 node101 chronyd[3566]: Source 124.108.20.1 replaced with 139.199.214.202 Sep 8 19:01:01 node101 systemd: Started Session 46 of user root. Sep 8 20:01:01 node101 systemd: Started Session 47 of user root. Sep 8 20:37:06 node101 chronyd[3566]: Selected source 139.199.214.202 Sep 8 20:58:19 node101 systemd-logind: Removed session 1. Sep 8 20:58:19 node101 systemd: Removed slice User Slice of root. Sep 8 21:01:01 node101 systemd: Created slice User Slice of root. Sep 8 21:01:01 node101 systemd: Started Session 48 of user root. Sep 8 21:01:01 node101 systemd: Removed slice User Slice of root. Sep 8 22:01:01 node101 systemd: Created slice User Slice of root. Sep 8 22:01:01 node101 systemd: Started Session 49 of user root. Sep 8 22:01:01 node101 systemd: Removed slice User Slice of root. Sep 8 23:01:01 node101 systemd: Created slice User Slice of root. Sep 8 23:01:01 node101 systemd: Started Session 50 of user root. Sep 8 23:01:01 node101 systemd: Removed slice User Slice of root. Sep 8 23:04:18 node101 systemd: Starting Cleanup of Temporary Directories... Sep 8 23:04:18 node101 systemd: Started Cleanup of Temporary Directories. Sep 8 23:51:00 node101 systemd: Created slice User Slice of root. Sep 8 23:51:00 node101 systemd-logind: New session 51 of user root. Sep 8 23:51:00 node101 systemd: Started Session 51 of user root. Sep 9 00:01:01 node101 systemd: Started Session 52 of user root. Sep 9 01:01:02 node101 systemd: Started Session 53 of user root. Sep 9 01:06:52 node101 NetworkManager[3613]: <info> [1568005612.4339] device (eth0): carrier: link connected Sep 9 02:00:03 node101 systemd-logind: Removed session 51. Sep 9 02:00:03 node101 systemd: Removed slice User Slice of root. --More--(2%)[Press space to continue, 'q' to quit.]
2>.less命令用于一页一页地查看文件或STDIN输出（功能较more更强，man命令底层就调用了less，因此man命令的一些快捷键在less命令上也是可以用的）
[root@node101.yinzhengjie.org.cn ~]# less --help #查看该命令的帮助信息 SUMMARY OF LESS COMMANDS Commands marked with * may be preceded by a number, N. Notes in parentheses indicate the behavior if N is given. A key preceded by a caret indicates the Ctrl key; thus ^K is ctrl-K. h H Display this help. q :q Q :Q ZZ Exit. --------------------------------------------------------------------------- MOVING e ^E j ^N CR * Forward one line (or N lines). y ^Y k ^K ^P * Backward one line (or N lines). f ^F ^V SPACE * Forward one window (or N lines). b ^B ESC-v * Backward one window (or N lines). z * Forward one window (and set window to N). w * Backward one window (and set window to N). ESC-SPACE * Forward one window, but don't stop at end-of-file. d ^D * Forward one half-window (and set half-window to N). u ^U * Backward one half-window (and set half-window to N). ESC-) RightArrow * Left one half screen width (or N positions). ESC-( LeftArrow * Right one half screen width (or N positions). F Forward forever; like "tail -f". r ^R ^L Repaint screen. R Repaint screen, discarding buffered input. --------------------------------------------------- Default "window" is the screen height. Default "half-window" is half of the screen height. --------------------------------------------------------------------------- SEARCHING /pattern * Search forward for (N-th) matching line. ?pattern * Search backward for (N-th) matching line. n * Repeat previous search (for N-th occurrence). N * Repeat previous search in reverse direction. ESC-n * Repeat previous search, spanning files. ESC-N * Repeat previous search, reverse dir. & spanning files. ESC-u Undo (toggle) search highlighting. &pattern * Display only matching lines --------------------------------------------------- A search pattern may be preceded by one or more of: ^N or ! Search for NON-matching lines. ^E or * Search multiple files (pass thru END OF FILE). ^F or @ Start search at FIRST file (for /) or last file (for ?). ^K Highlight matches, but don't move (KEEP position). ^R Don't use REGULAR EXPRESSIONS. --------------------------------------------------------------------------- JUMPING g < ESC-< * Go to first line in file (or line N). G > ESC-> * Go to last line in file (or line N). p % * Go to beginning of file (or N percent into file). t * Go to the (N-th) next tag. T * Go to the (N-th) previous tag. { ( [ * Find close bracket } ) ]. } ) ] * Find open bracket { ( [. ESC-^F <c1> <c2> * Find close bracket <c2>. ESC-^B <c1> <c2> * Find open bracket <c1> --------------------------------------------------- Each "find close bracket" command goes forward to the close bracket matching the (N-th) open bracket in the top line. Each "find open bracket" command goes backward to the open bracket matching the (N-th) close bracket in the bottom line. m<letter> Mark the current position with <letter>. '<letter> Go to a previously marked position. '' Go to the previous position. ^X^X Same as '. --------------------------------------------------- A mark is any upper-case or lower-case letter. Certain marks are predefined: ^ means beginning of the file $ means end of the file --------------------------------------------------------------------------- CHANGING FILES :e [file] Examine a new file. ^X^V Same as :e. :n * Examine the (N-th) next file from the command line. :p * Examine the (N-th) previous file from the command line. :x * Examine the first (or N-th) file from the command line. :d Delete the current file from the command line list. = ^G :f Print current file name. --------------------------------------------------------------------------- MISCELLANEOUS COMMANDS -<flag> Toggle a command line option [see OPTIONS below]. --<name> Toggle a command line option, by name. _<flag> Display the setting of a command line option. __<name> Display the setting of an option, by name. +cmd Execute the less cmd each time a new file is examined. !command Execute the shell command with $SHELL. |Xcommand Pipe file between current pos & mark X to shell command. v Edit the current file with $VISUAL or $EDITOR. V Print version number of "less". --------------------------------------------------------------------------- OPTIONS Most options may be changed either on the command line, or from within less by using the - or -- command. Options may be given in one of two forms: either a single character preceded by a -, or a name preceded by --. -? ........ --help Display help (from command line). -a ........ --search-skip-screen Search skips current screen. -A ........ --SEARCH-SKIP-SCREEN Search starts just after target line. -b [N] .... --buffers=[N] Number of buffers. -B ........ --auto-buffers Don't automatically allocate buffers for pipes. -c -C .... --clear-screen --CLEAR-SCREEN Repaint by clearing rather than scrolling. -d ........ --dumb Dumb terminal. -D [xn.n] . --color=xn.n Set screen colors. (MS-DOS only) -e -E .... --quit-at-eof --QUIT-AT-EOF Quit at end of file. -f ........ --force Force open non-regular files. -F ........ --quit-if-one-screen Quit if entire file fits on first screen. -g ........ --hilite-search Highlight only last match for searches. -G ........ --HILITE-SEARCH Don't highlight any matches for searches. --old-bot Revert to the old bottom of screen behavior. -h [N] .... --max-back-scroll=[N] Backward scroll limit. -i ........ --ignore-case Ignore case in searches that do not contain uppercase. -I ........ --IGNORE-CASE Ignore case in all searches. -j [N] .... --jump-target=[N] Screen position of target lines. -J ........ --status-column Display a status column at left edge of screen. -k [file] . --lesskey-file=[file] Use a lesskey file. -K --quit-on-intr Exit less in response to ctrl-C. -L ........ --no-lessopen Ignore the LESSOPEN environment variable. -m -M .... --long-prompt --LONG-PROMPT Set prompt style. -n ........ --line-numbers Don't use line numbers. -N ........ --LINE-NUMBERS Use line numbers. -o [file] . --log-file=[file] Copy to log file (standard input only). -O [file] . --LOG-FILE=[file] Copy to log file (unconditionally overwrite). -p [pattern] --pattern=[pattern] Start at pattern (from command line). -P [prompt] --prompt=[prompt] Define new prompt. -q -Q .... --quiet --QUIET --silent --SILENT Quiet the terminal bell. -r -R .... --raw-control-chars --RAW-CONTROL-CHARS Output "raw" control characters. -s ........ --squeeze-blank-lines Squeeze multiple blank lines. -S ........ --chop-long-lines Chop (truncate) long lines rather than wrapping. -t [tag] .. --tag=[tag] Find a tag. -T [tagsfile] --tag-file=[tagsfile] Use an alternate tags file. -u -U .... --underline-special --UNDERLINE-SPECIAL Change handling of backspaces. -V ........ --version Display the version number of "less". -w ........ --hilite-unread Highlight first new line after forward-screen. -W ........ --HILITE-UNREAD Highlight first new line after any forward movement. -x [N[,...]] --tabs=[N[,...]] Set tab stops. -X ........ --no-init Don't use termcap init/deinit strings. -y [N] .... --max-forw-scroll=[N] Forward scroll limit. -z [N] .... --window=[N] Set size of window. -" [c[c]] . --quotes=[c[c]] Set shell quote characters. -~ ........ --tilde Don't display tildes after end of file. -# [N] .... --shift=[N] Horizontal scroll amount (0 = one half screen width) ........ --no-keypad Don't send termcap keypad init/deinit strings. ........ --follow-name The F command changes files if the input file is renamed. ........ --use-backslash Subsequent options use backslash as escape char. --------------------------------------------------------------------------- LINE EDITING These keys can be used to edit text being entered on the "command line" at the bottom of the screen. RightArrow ESC-l Move cursor right one character. LeftArrow ESC-h Move cursor left one character. ctrl-RightArrow ESC-RightArrow ESC-w Move cursor right one word. ctrl-LeftArrow ESC-LeftArrow ESC-b Move cursor left one word. HOME ESC-0 Move cursor to start of line. END ESC-$ Move cursor to end of line. BACKSPACE Delete char to left of cursor. DELETE ESC-x Delete char under cursor. ctrl-BACKSPACE ESC-BACKSPACE Delete word to left of cursor. ctrl-DELETE ESC-DELETE ESC-X Delete word under cursor. ctrl-U ESC (MS-DOS only) Delete entire line. UpArrow ESC-k Retrieve previous command line. DownArrow ESC-j Retrieve next command line. TAB Complete filename & cycle. SHIFT-TAB ESC-TAB Complete filename & reverse cycle. ctrl-L Complete filename, list all. [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# less /var/log/messages Sep 8 03:41:01 node101 rsyslogd: [origin software="rsyslogd" swVersion="8.24.0-34.el7" x-pid="4104" x-info="http://www.rsyslog.com"] rsyslogd was HUPed Sep 8 04:01:01 node101 systemd: Started Session 31 of user root. Sep 8 05:01:01 node101 systemd: Started Session 32 of user root. Sep 8 06:01:01 node101 systemd: Started Session 33 of user root. Sep 8 07:01:01 node101 systemd: Started Session 34 of user root. Sep 8 08:01:01 node101 systemd: Started Session 35 of user root. Sep 8 08:15:17 node101 chronyd[3566]: Source 193.228.143.12 replaced with 124.108.20.1 Sep 8 09:01:01 node101 systemd: Started Session 36 of user root. Sep 8 10:01:01 node101 systemd: Started Session 37 of user root. Sep 8 11:01:01 node101 systemd: Started Session 38 of user root. Sep 8 12:01:01 node101 systemd: Started Session 39 of user root. Sep 8 13:00:23 node101 chronyd[3566]: Can't synchronise: no selectable sources Sep 8 13:01:01 node101 systemd: Started Session 40 of user root. Sep 8 14:01:01 node101 systemd: Started Session 41 of user root. Sep 8 15:01:01 node101 systemd: Started Session 42 of user root. Sep 8 16:01:01 node101 systemd: Started Session 43 of user root. Sep 8 17:01:02 node101 systemd: Started Session 44 of user root. Sep 8 18:01:01 node101 systemd: Started Session 45 of user root. Sep 8 18:10:15 node101 chronyd[3566]: Selected source 45.43.30.59 Sep 8 18:36:16 node101 chronyd[3566]: Source 124.108.20.1 replaced with 139.199.214.202 Sep 8 19:01:01 node101 systemd: Started Session 46 of user root. Sep 8 20:01:01 node101 systemd: Started Session 47 of user root. Sep 8 20:37:06 node101 chronyd[3566]: Selected source 139.199.214.202 Sep 8 20:58:19 node101 systemd-logind: Removed session 1. Sep 8 20:58:19 node101 systemd: Removed slice User Slice of root. Sep 8 21:01:01 node101 systemd: Created slice User Slice of root. Sep 8 21:01:01 node101 systemd: Started Session 48 of user root. Sep 8 21:01:01 node101 systemd: Removed slice User Slice of root. Sep 8 22:01:01 node101 systemd: Created slice User Slice of root. Sep 8 22:01:01 node101 systemd: Started Session 49 of user root. Sep 8 22:01:01 node101 systemd: Removed slice User Slice of root. Sep 8 23:01:01 node101 systemd: Created slice User Slice of root. Sep 8 23:01:01 node101 systemd: Started Session 50 of user root. Sep 8 23:01:01 node101 systemd: Removed slice User Slice of root. Sep 8 23:04:18 node101 systemd: Starting Cleanup of Temporary Directories... Sep 8 23:04:18 node101 systemd: Started Cleanup of Temporary Directories. Sep 8 23:51:00 node101 systemd: Created slice User Slice of root. Sep 8 23:51:00 node101 systemd-logind: New session 51 of user root. Sep 8 23:51:00 node101 systemd: Started Session 51 of user root. Sep 9 00:01:01 node101 systemd: Started Session 52 of user root. Sep 9 01:01:02 node101 systemd: Started Session 53 of user root. Sep 9 01:06:52 node101 NetworkManager[3613]: <info> [1568005612.4339] device (eth0): carrier: link connected Sep 9 02:00:03 node101 systemd-logind: Removed session 51. Sep 9 02:00:03 node101 systemd: Removed slice User Slice of root. /var/log/messages
四.显示文本前或后行内容
1>.head
[root@node101.yinzhengjie.org.cn ~]# head --help #查看该命令的帮助信息 Usage: head [OPTION]... [FILE]... Print the first 10 lines of each FILE to standard output. With more than one FILE, precede each with a header giving the file name. With no FILE, or when FILE is -, read standard input. Mandatory arguments to long options are mandatory for short options too. -c, --bytes=[-]K print the first K bytes of each file; with the leading '-', print all but the last K bytes of each file -n, --lines=[-]K print the first K lines instead of the first 10; with the leading '-', print all but the last K lines of each file -q, --quiet, --silent never print headers giving file names -v, --verbose always print headers giving file names --help display this help and exit --version output version information and exit K may have a multiplier suffix: b 512, kB 1000, K 1024, MB 1000*1000, M 1024*1024, GB 1000*1000*1000, G 1024*1024*1024, and so on for T, P, E, Z, Y. GNU coreutils online help: <http://www.gnu.org/software/coreutils/> For complete documentation, run: info coreutils 'head invocation' [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# seq 100 > f1.txt [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# head f1.txt 1 2 3 4 5 6 7 8 9 10 [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# head -n 5 f1.txt #只看前5行 1 2 3 4 5 [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# head -5 f1.txt #和上面一样，可以不写"-n",咱们可以简写 1 2 3 4 5 [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# echo "jason" | head -c 3 #很显然，只显示了三个字节，没有换行符。 jas[root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# echo "尹正杰到此一游" | head -c9 #虽说我们这样可以让其显示9个字节，但是由于Linux默认使用UTF-8编码，因此一个汉字一般情况下默认对应3个字节，最终输出"尹正杰"，注意没有换行符哟～ 尹正杰[root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# cat /dev/urandom | tr -dc 'a-zA-Z0-9' | head -c 12 #快速生成12个随机字符 XzTSsQdf5NmX[root@node101.yinzhengjie.org.cn ~]# cat /dev/urandom | tr -dc 'a-zA-Z0-9' | head -c 12 EyUrxFQTelEs[root@node101.yinzhengjie.org.cn ~]# cat /dev/urandom | tr -dc 'a-zA-Z0-9' | head -c 12 FLALxqxAoPGr[root@node101.yinzhengjie.org.cn ~]# cat /dev/urandom | tr -dc 'a-zA-Z0-9' | head -c 12 1r43iy0ofpCO[root@node101.yinzhengjie.org.cn ~]# cat /dev/urandom | tr -dc 'a-zA-Z0-9' | head -c 12 oUVoKrBqbNCm[root@node101.yinzhengjie.org.cn ~]# cat /dev/urandom | tr -dc 'a-zA-Z0-9' | head -c 12 f8gpt0mqSoxk[root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]#
2>.tail
[root@node101.yinzhengjie.org.cn ~]# tail --help #查看该命令的帮助信息 Usage: tail [OPTION]... [FILE]... Print the last 10 lines of each FILE to standard output. With more than one FILE, precede each with a header giving the file name. With no FILE, or when FILE is -, read standard input. Mandatory arguments to long options are mandatory for short options too. -c, --bytes=K output the last K bytes; or use -c +K to output bytes starting with the Kth of each file -f, --follow[={name|descriptor}] output appended data as the file grows; an absent option argument means 'descriptor' -F same as --follow=name --retry -n, --lines=K output the last K lines, instead of the last 10; or use -n +K to output starting with the Kth --max-unchanged-stats=N with --follow=name, reopen a FILE which has not changed size after N (default 5) iterations to see if it has been unlinked or renamed (this is the usual case of rotated log files); with inotify, this option is rarely useful --pid=PID with -f, terminate after process ID, PID dies -q, --quiet, --silent never output headers giving file names --retry keep trying to open a file if it is inaccessible -s, --sleep-interval=N with -f, sleep for approximately N seconds (default 1.0) between iterations; with inotify and --pid=P, check process P at least once every N seconds -v, --verbose always output headers giving file names --help display this help and exit --version output version information and exit If the first character of K (the number of bytes or lines) is a '+', print beginning with the Kth item from the start of each file, otherwise, print the last K items in the file. K may have a multiplier suffix: b 512, kB 1000, K 1024, MB 1000*1000, M 1024*1024, GB 1000*1000*1000, G 1024*1024*1024, and so on for T, P, E, Z, Y. With --follow (-f), tail defaults to following the file descriptor, which means that even if a tail'ed file is renamed, tail will continue to track its end. This default behavior is not desirable when you really want to track the actual name of the file, not the file descriptor (e.g., log rotation). Use --follow=name in that case. That causes tail to track the named file in a way that accommodates renaming, removal and creation. GNU coreutils online help: <http://www.gnu.org/software/coreutils/> For complete documentation, run: info coreutils 'tail invocation' [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# tail f1.txt #和head命令类似，如果我们不指定显示的行数那默认就显示10行。 91 92 93 94 95 96 97 98 99 100 [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# tail -n 3 f1.txt #显示后3行 98 99 100 [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# tail -3 f1.txt #同上，一种简写形式 98 99 100 [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# tail -10f /var/log/messages Oct 17 21:26:37 node101 chronyd[3584]: Selected source 139.199.214.202 Oct 17 21:26:57 node101 systemd: Created slice User Slice of root. Oct 17 21:26:57 node101 systemd-logind: New session 4 of user root. Oct 17 21:26:57 node101 systemd: Started Session 4 of user root. Oct 17 21:38:42 node101 systemd: Starting Cleanup of Temporary Directories... Oct 17 21:38:43 node101 systemd: Started Cleanup of Temporary Directories. Oct 17 22:01:01 node101 systemd: Started Session 5 of user root. Oct 17 22:26:53 node101 yum[4828]: Installed: 2:vim-filesystem-7.4.629-6.el7.x86_64 Oct 17 22:26:56 node101 yum[4828]: Installed: 2:vim-common-7.4.629-6.el7.x86_64 Oct 17 23:01:01 node101 systemd: Started Session 6 of user root. 尹正杰到此一游 #注意：我们此时开启另一个终端，只要往"/var/log/messages"文件写入东西就可以被监听到哟～
[root@node101.yinzhengjie.org.cn ~]# tail -F f1.txt #跟踪文件名，当文件被删除时会有相应的提示信息，当文件被新建后依旧还会监控该文件内容 91 92 93 94 95 96 97 98 99 100 tail: ‘f1.txt’ has become inaccessible: No such file or directory 注意，如果此时我们执行了一些标准错误信息如果使用"-F"参数监听文件的话也会被写进去，比如我们另外开启一个终端执行"rm -f f1.txt"就会出现上面最后一行的错误信息提示哟～
[root@node101.yinzhengjie.org.cn ~]# pidof tail #查看某个进程的文件描述符 4962 [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# ll /proc/`pidof tail`/fd #同过这种方式就可以看到tail命令对应的文件描述符 total 0 lrwx------. 1 root root 64 Oct 17 23:28 0 -> /dev/pts/0 lrwx------. 1 root root 64 Oct 17 23:28 1 -> /dev/pts/0 lrwx------. 1 root root 64 Oct 17 23:28 2 -> /dev/pts/0 lr-x------. 1 root root 64 Oct 17 23:29 3 -> /root/f1.txt lr-x------. 1 root root 64 Oct 17 23:28 4 -> anon_inode:inotify [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]#
3>.tailf(和tail -f类似，当文件不增长时并不访问文件)
[root@node101.yinzhengjie.org.cn ~]# tailf /var/log/messages Oct 17 21:26:57 node101 systemd: Created slice User Slice of root. Oct 17 21:26:57 node101 systemd-logind: New session 4 of user root. Oct 17 21:26:57 node101 systemd: Started Session 4 of user root. Oct 17 21:38:42 node101 systemd: Starting Cleanup of Temporary Directories... Oct 17 21:38:43 node101 systemd: Started Cleanup of Temporary Directories. Oct 17 22:01:01 node101 systemd: Started Session 5 of user root. Oct 17 22:26:53 node101 yum[4828]: Installed: 2:vim-filesystem-7.4.629-6.el7.x86_64 Oct 17 22:26:56 node101 yum[4828]: Installed: 2:vim-common-7.4.629-6.el7.x86_64 Oct 17 23:01:01 node101 systemd: Started Session 6 of user root. 尹正杰到此一游 c
五.按列抽取文本cut
1>.查看cut帮助信息
[root@node101.yinzhengjie.org.cn ~]# cut --help #查看该命令的帮助信息 Usage: cut OPTION... [FILE]... Print selected parts of lines from each FILE to standard output. Mandatory arguments to long options are mandatory for short options too. -b, --bytes=LIST select only these bytes -c, --characters=LIST select only these characters -d, --delimiter=DELIM use DELIM instead of TAB for field delimiter -f, --fields=LIST select only these fields; also print any line that contains no delimiter character, unless the -s option is specified -n with -b: don't split multibyte characters --complement complement the set of selected bytes, characters or fields -s, --only-delimited do not print lines not containing delimiters --output-delimiter=STRING use STRING as the output delimiter the default is to use the input delimiter --help display this help and exit --version output version information and exit Use one, and only one of -b, -c or -f. Each LIST is made up of one range, or many ranges separated by commas. Selected input is written in the same order that it is read, and is written exactly once. Each range is one of: N N'th byte, character or field, counted from 1 N- from N'th byte, character or field, to end of line N-M from N'th to M'th (included) byte, character or field -M from first to M'th (included) byte, character or field With no FILE, or when FILE is -, read standard input. GNU coreutils online help: <http://www.gnu.org/software/coreutils/> For complete documentation, run: info coreutils 'cut invocation' [root@node101.yinzhengjie.org.cn ~]#
2>.cut命令案例
[root@node101.yinzhengjie.org.cn ~]# cat /etc/passwd root:x:0:0:root:/root:/bin/bash bin:x:1:1:bin:/bin:/sbin/nologin daemon:x:2:2:daemon:/sbin:/sbin/nologin adm:x:3:4:adm:/var/adm:/sbin/nologin lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin sync:x:5:0:sync:/sbin:/bin/sync shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown halt:x:7:0:halt:/sbin:/sbin/halt mail:x:8:12:mail:/var/spool/mail:/sbin/nologin operator:x:11:0:operator:/root:/sbin/nologin games:x:12:100:games:/usr/games:/sbin/nologin ftp:x:14:50:FTP User:/var/ftp:/sbin/nologin nobody:x:99:99:Nobody:/:/sbin/nologin systemd-network:x:192:192:systemd Network Management:/:/sbin/nologin dbus:x:81:81:System message bus:/:/sbin/nologin polkitd:x:999:998:User for polkitd:/:/sbin/nologin sshd:x:74:74:Privilege-separated SSH:/var/empty/sshd:/sbin/nologin postfix:x:89:89::/var/spool/postfix:/sbin/nologin chrony:x:998:996::/var/lib/chrony:/sbin/nologin yinzhengjie:x:1000:1000::/home/yinzhengjie:/bin/bash [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# cut -d : -f 1,3,7 /etc/passwd #我们使用"=d"参数指定分隔符为":",使用"-f"指定我们要获取的列分别为"1,3,7"这三列数据。 root:0:/bin/bash bin:1:/sbin/nologin daemon:2:/sbin/nologin adm:3:/sbin/nologin lp:4:/sbin/nologin sync:5:/bin/sync shutdown:6:/sbin/shutdown halt:7:/sbin/halt mail:8:/sbin/nologin operator:11:/sbin/nologin games:12:/sbin/nologin ftp:14:/sbin/nologin nobody:99:/sbin/nologin systemd-network:192:/sbin/nologin dbus:81:/sbin/nologin polkitd:999:/sbin/nologin sshd:74:/sbin/nologin postfix:89:/sbin/nologin chrony:998:/sbin/nologin yinzhengjie:1000:/bin/bash [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# cat /etc/passwd root:x:0:0:root:/root:/bin/bash bin:x:1:1:bin:/bin:/sbin/nologin daemon:x:2:2:daemon:/sbin:/sbin/nologin adm:x:3:4:adm:/var/adm:/sbin/nologin lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin sync:x:5:0:sync:/sbin:/bin/sync shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown halt:x:7:0:halt:/sbin:/sbin/halt mail:x:8:12:mail:/var/spool/mail:/sbin/nologin operator:x:11:0:operator:/root:/sbin/nologin games:x:12:100:games:/usr/games:/sbin/nologin ftp:x:14:50:FTP User:/var/ftp:/sbin/nologin nobody:x:99:99:Nobody:/:/sbin/nologin systemd-network:x:192:192:systemd Network Management:/:/sbin/nologin dbus:x:81:81:System message bus:/:/sbin/nologin polkitd:x:999:998:User for polkitd:/:/sbin/nologin sshd:x:74:74:Privilege-separated SSH:/var/empty/sshd:/sbin/nologin postfix:x:89:89::/var/spool/postfix:/sbin/nologin chrony:x:998:996::/var/lib/chrony:/sbin/nologin yinzhengjie:x:1000:1000::/home/yinzhengjie:/bin/bash [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# cat /etc/passwd | cut -d : -f 1-5 --output-delimiter=##### #我们可以自定义输出的没列之间的分隔符哟～我这里就用了"#####"来作为分隔符呢！ root#####x#####0#####0#####root bin#####x#####1#####1#####bin daemon#####x#####2#####2#####daemon adm#####x#####3#####4#####adm lp#####x#####4#####7#####lp sync#####x#####5#####0#####sync shutdown#####x#####6#####0#####shutdown halt#####x#####7#####0#####halt mail#####x#####8#####12#####mail operator#####x#####11#####0#####operator games#####x#####12#####100#####games ftp#####x#####14#####50#####FTP User nobody#####x#####99#####99#####Nobody systemd-network#####x#####192#####192#####systemd Network Management dbus#####x#####81#####81#####System message bus polkitd#####x#####999#####998#####User for polkitd sshd#####x#####74#####74#####Privilege-separated SSH postfix#####x#####89#####89##### chrony#####x#####998#####996##### yinzhengjie#####x#####1000#####1000##### [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# who root pts/0 2019-10-17 21:26 (172.30.1.2) root pts/1 2019-10-17 23:14 (172.30.1.2) [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# who | cut -d " " -f 1 #取出当前登陆用户 root root [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# ifconfig eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 172.30.1.101 netmask 255.255.255.0 broadcast 172.30.1.255 inet6 fe80::21c:42ff:fefb:c98a prefixlen 64 scopeid 0x20<link> ether 00:1c:42:fb:c9:8a txqueuelen 1000 (Ethernet) RX packets 25774 bytes 26008520 (24.8 MiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 9045 bytes 2050740 (1.9 MiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536 inet 127.0.0.1 netmask 255.0.0.0 inet6 ::1 prefixlen 128 scopeid 0x10<host> loop txqueuelen 1000 (Local Loopback) RX packets 64 bytes 5792 (5.6 KiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 64 bytes 5792 (5.6 KiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# ifconfig eth0 | head -2 | tail -1 | tr -s " " | cut -d " " -f 3 #使用cut取出IP地址 172.30.1.101 [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# cat /etc/passwd | cut -c 1-15 #只取出前15个字符 root:x:0:0:root bin:x:1:1:bin:/ daemon:x:2:2:da adm:x:3:4:adm:/ lp:x:4:7:lp:/va sync:x:5:0:sync shutdown:x:6:0: halt:x:7:0:halt mail:x:8:12:mai operator:x:11:0 games:x:12:100: ftp:x:14:50:FTP nobody:x:99:99: systemd-network dbus:x:81:81:Sy polkitd:x:999:9 sshd:x:74:74:Pr postfix:x:89:89 chrony:x:998:99 yinzhengjie:x:1 [root@node101.yinzhengjie.org.cn ~]#
六.合并文件paste
1>.查看帮助信息
[root@node101.yinzhengjie.org.cn ~]# paste --help Usage: paste [OPTION]... [FILE]... Write lines consisting of the sequentially corresponding lines from each FILE, separated by TABs, to standard output. With no FILE, or when FILE is -, read standard input. Mandatory arguments to long options are mandatory for short options too. -d, --delimiters=LIST reuse characters from LIST instead of TABs -s, --serial paste one file at a time instead of in parallel --help display this help and exit --version output version information and exit GNU coreutils online help: <http://www.gnu.org/software/coreutils/> For complete documentation, run: info coreutils 'paste invocation' [root@node101.yinzhengjie.org.cn ~]#
2>.paste命令案例
[root@node101.yinzhengjie.org.cn ~]# seq 5 > f1.txt [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# cat f1.txt 1 2 3 4 5 [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# echo {a..g} | tr ' ' '\n' > f2.txt [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# cat f2.txt a b c d e f g [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# paste f1.txt f2.txt #横向合并2个内容，若不指定分隔符，默认以TAB制表符进行分割。 1 a 2 b 3 c 4 d 5 e f g [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# paste f1.txt f2.txt | cat -A #不难发现，paste默认以空格进行分割2个文件行内容 1^Ia$ 2^Ib$ 3^Ic$ 4^Id$ 5^Ie$ ^If$ ^Ig$ [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# paste f1.txt f2.txt | cat -A #默认以TAB制表符作为分隔符 1^Ia$ 2^Ib$ 3^Ic$ 4^Id$ 5^Ie$ ^If$ ^Ig$ [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# paste -d ":" f1.txt f2.txt #我们这里使用"-d"选项指定分隔符为":" 1:a 2:b 3:c 4:d 5:e :f :g [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# cat f1.txt 1 2 3 4 5 [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# cat f2.txt a b c d e f g [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# paste -s f1.txt f2.txt #将每个文件的内容合并成一行显示，每行分隔符不指定默认为TAB制表符 1 2 3 4 5 a b c d e f g [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# paste -s f1.txt f2.txt | cat -A 1^I2^I3^I4^I5$ a^Ib^Ic^Id^Ie^If^Ig$ [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# paste -d ":" f1.txt f2.txt -s #这里现实制定了分隔符为":" 1:2:3:4:5 a:b:c:d:e:f:g [root@node101.yinzhengjie.org.cn ~]#
七.分析文本的工具
1>.文本数据统计：wc命令(可用于统计文件的行总数，单词总数，字节总数和字符总数，以及对文件或STDIN中的数据统计)
[root@node101.yinzhengjie.org.cn ~]# wc --help #查看该命令的帮助信息 Usage: wc [OPTION]... [FILE]... or: wc [OPTION]... --files0-from=F Print newline, word, and byte counts for each FILE, and a total line if more than one FILE is specified. With no FILE, or when FILE is -, read standard input. A word is a non-zero-length sequence of characters delimited by white space. The options below may be used to select which counts are printed, always in the following order: newline, word, character, byte, maximum line length. -c, --bytes print the byte counts -m, --chars print the character counts -l, --lines print the newline counts --files0-from=F read input from the files specified by NUL-terminated names in file F; If F is - then read names from standard input -L, --max-line-length print the length of the longest line -w, --words print the word counts --help display this help and exit --version output version information and exit GNU coreutils online help: <http://www.gnu.org/software/coreutils/> For complete documentation, run: info coreutils 'wc invocation' [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# cat hadoop.txt The Apache Hadoop software library is a framework that allows for the distributed processing of large data sets across clusters of computers using simple programming models. It is designed to scale up from single servers to thousands of machines, each offering local computation and storage. Rather than rely on hardware to deliver high-availability, the library itself is designed to detect and handle failures at the application layer, so delivering a highly-available service on top of a cluster of computers, each of which may be prone to failures. [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# wc hadoop.txt #注意输出的4列参数表示的意思，第一列表示该文件共有多少行，第二列表示该文件共计有多少个单词，第三列表示该文件共有多少字节，第四列表示该文件的名称。 1 87 553 hadoop.txt [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# cat f1.txt 1 linux 2 hadoop 3 python 4 java c++ 5 golang [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# wc f1.txt 5 11 46 f1.txt [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# wc -l f1.txt #只计数行数 5 f1.txt [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# cat f1.txt 1 linux 2 hadoop 3 python 4 java c++ 5 golang [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# wc f1.txt 5 11 46 f1.txt [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# wc -w f1.txt #只计数单词总数 11 f1.txt [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# cat f1.txt 1 linux 2 hadoop 3 python 4 java c++ 5 golang [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# wc f1.txt 5 11 46 f1.txt [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# wc -c f1.txt #只计数字节总数 46 f1.txt [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# cat f1.txt 1 linux 2 hadoop 3 python 4 java c++ 5 golang [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# wc f1.txt 5 11 46 f1.txt [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# wc -m f1.txt #只计数字符总数 46 f1.txt [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# cat f1.txt 1 linux 2 hadoop 3 python 4 java c++ 5 golang [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# wc f1.txt 5 11 46 f1.txt [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# wc -L f1.txt #只显示文件中最长行的长度 10 f1.txt [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]#
2>.整理文本：sort命令(把整理过的文本显示在STDOUT，不改变原始文件)和uniq命令(从输入中删除前后相接的重复的行)
[root@node101.yinzhengjie.org.cn ~]# sort --help #显示该命令的帮助信息 Usage: sort [OPTION]... [FILE]... or: sort [OPTION]... --files0-from=F Write sorted concatenation of all FILE(s) to standard output. Mandatory arguments to long options are mandatory for short options too. Ordering options: -b, --ignore-leading-blanks ignore leading blanks -d, --dictionary-order consider only blanks and alphanumeric characters -f, --ignore-case fold lower case to upper case characters -g, --general-numeric-sort compare according to general numerical value -i, --ignore-nonprinting consider only printable characters -M, --month-sort compare (unknown) < 'JAN' < ... < 'DEC' -h, --human-numeric-sort compare human readable numbers (e.g., 2K 1G) -n, --numeric-sort compare according to string numerical value -R, --random-sort sort by random hash of keys --random-source=FILE get random bytes from FILE -r, --reverse reverse the result of comparisons --sort=WORD sort according to WORD: general-numeric -g, human-numeric -h, month -M, numeric -n, random -R, version -V -V, --version-sort natural sort of (version) numbers within text Other options: --batch-size=NMERGE merge at most NMERGE inputs at once; for more use temp files -c, --check, --check=diagnose-first check for sorted input; do not sort -C, --check=quiet, --check=silent like -c, but do not report first bad line --compress-program=PROG compress temporaries with PROG; decompress them with PROG -d --debug annotate the part of the line used to sort, and warn about questionable usage to stderr --files0-from=F read input from the files specified by NUL-terminated names in file F; If F is - then read names from standard input -k, --key=KEYDEF sort via a key; KEYDEF gives location and type -m, --merge merge already sorted files; do not sort -o, --output=FILE write result to FILE instead of standard output -s, --stable stabilize sort by disabling last-resort comparison -S, --buffer-size=SIZE use SIZE for main memory buffer -t, --field-separator=SEP use SEP instead of non-blank to blank transition -T, --temporary-directory=DIR use DIR for temporaries, not $TMPDIR or /tmp; multiple options specify multiple directories --parallel=N change the number of sorts run concurrently to N -u, --unique with -c, check for strict ordering; without -c, output only the first of an equal run -z, --zero-terminated end lines with 0 byte, not newline --help display this help and exit --version output version information and exit KEYDEF is F[.C][OPTS][,F[.C][OPTS]] for start and stop position, where F is a field number and C a character position in the field; both are origin 1, and the stop position defaults to the line's end. If neither -t nor -b is in effect, characters in a field are counted from the beginning of the preceding whitespace. OPTS is one or more single-letter ordering options [bdfgiMhnRrV], which override global ordering options for that key. If no key is given, use the entire line as the key. SIZE may be followed by the following multiplicative suffixes: % 1% of memory, b 1, K 1024 (default), and so on for M, G, T, P, E, Z, Y. With no FILE, or when FILE is -, read standard input. *** WARNING *** The locale specified by the environment affects sort order. Set LC_ALL=C to get the traditional sort order that uses native byte values. GNU coreutils online help: <http://www.gnu.org/software/coreutils/> For complete documentation, run: info coreutils 'sort invocation' [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# cat /etc/passwd root:x:0:0:root:/root:/bin/bash bin:x:1:1:bin:/bin:/sbin/nologin daemon:x:2:2:daemon:/sbin:/sbin/nologin adm:x:3:4:adm:/var/adm:/sbin/nologin lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin sync:x:5:0:sync:/sbin:/bin/sync shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown halt:x:7:0:halt:/sbin:/sbin/halt mail:x:8:12:mail:/var/spool/mail:/sbin/nologin operator:x:11:0:operator:/root:/sbin/nologin games:x:12:100:games:/usr/games:/sbin/nologin ftp:x:14:50:FTP User:/var/ftp:/sbin/nologin nobody:x:99:99:Nobody:/:/sbin/nologin systemd-network:x:192:192:systemd Network Management:/:/sbin/nologin dbus:x:81:81:System message bus:/:/sbin/nologin polkitd:x:999:998:User for polkitd:/:/sbin/nologin sshd:x:74:74:Privilege-separated SSH:/var/empty/sshd:/sbin/nologin postfix:x:89:89::/var/spool/postfix:/sbin/nologin chrony:x:998:996::/var/lib/chrony:/sbin/nologin yinzhengjie:x:1000:1000::/home/yinzhengjie:/bin/bash [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# sort /etc/passwd #默认会按照每一行的第一个字符进行排序，主要根据ASCII编码表顺序来排序。 adm:x:3:4:adm:/var/adm:/sbin/nologin bin:x:1:1:bin:/bin:/sbin/nologin chrony:x:998:996::/var/lib/chrony:/sbin/nologin daemon:x:2:2:daemon:/sbin:/sbin/nologin dbus:x:81:81:System message bus:/:/sbin/nologin ftp:x:14:50:FTP User:/var/ftp:/sbin/nologin games:x:12:100:games:/usr/games:/sbin/nologin halt:x:7:0:halt:/sbin:/sbin/halt lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin mail:x:8:12:mail:/var/spool/mail:/sbin/nologin nobody:x:99:99:Nobody:/:/sbin/nologin operator:x:11:0:operator:/root:/sbin/nologin polkitd:x:999:998:User for polkitd:/:/sbin/nologin postfix:x:89:89::/var/spool/postfix:/sbin/nologin root:x:0:0:root:/root:/bin/bash shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown sshd:x:74:74:Privilege-separated SSH:/var/empty/sshd:/sbin/nologin sync:x:5:0:sync:/sbin:/bin/sync systemd-network:x:192:192:systemd Network Management:/:/sbin/nologin yinzhengjie:x:1000:1000::/home/yinzhengjie:/bin/bash [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# cat /etc/passwd root:x:0:0:root:/root:/bin/bash bin:x:1:1:bin:/bin:/sbin/nologin daemon:x:2:2:daemon:/sbin:/sbin/nologin adm:x:3:4:adm:/var/adm:/sbin/nologin lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin sync:x:5:0:sync:/sbin:/bin/sync shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown halt:x:7:0:halt:/sbin:/sbin/halt mail:x:8:12:mail:/var/spool/mail:/sbin/nologin operator:x:11:0:operator:/root:/sbin/nologin games:x:12:100:games:/usr/games:/sbin/nologin ftp:x:14:50:FTP User:/var/ftp:/sbin/nologin nobody:x:99:99:Nobody:/:/sbin/nologin systemd-network:x:192:192:systemd Network Management:/:/sbin/nologin dbus:x:81:81:System message bus:/:/sbin/nologin polkitd:x:999:998:User for polkitd:/:/sbin/nologin sshd:x:74:74:Privilege-separated SSH:/var/empty/sshd:/sbin/nologin postfix:x:89:89::/var/spool/postfix:/sbin/nologin chrony:x:998:996::/var/lib/chrony:/sbin/nologin yinzhengjie:x:1000:1000::/home/yinzhengjie:/bin/bash [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# sort -t ":" -k 3 -n /etc/passwd #"-t"参数表示指定分隔符，我这里指定冒号(":")为分隔符,"-k"表示指定以那一列进行排序，我这里指定基于用户的uid进行排序(即第3列)，"-n"参数表示将第三列当初数字(number)进行比较，若不加该参数默认以字符串进行比较。 root:x:0:0:root:/root:/bin/bash bin:x:1:1:bin:/bin:/sbin/nologin daemon:x:2:2:daemon:/sbin:/sbin/nologin adm:x:3:4:adm:/var/adm:/sbin/nologin lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin sync:x:5:0:sync:/sbin:/bin/sync shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown halt:x:7:0:halt:/sbin:/sbin/halt mail:x:8:12:mail:/var/spool/mail:/sbin/nologin operator:x:11:0:operator:/root:/sbin/nologin games:x:12:100:games:/usr/games:/sbin/nologin ftp:x:14:50:FTP User:/var/ftp:/sbin/nologin sshd:x:74:74:Privilege-separated SSH:/var/empty/sshd:/sbin/nologin dbus:x:81:81:System message bus:/:/sbin/nologin postfix:x:89:89::/var/spool/postfix:/sbin/nologin nobody:x:99:99:Nobody:/:/sbin/nologin systemd-network:x:192:192:systemd Network Management:/:/sbin/nologin chrony:x:998:996::/var/lib/chrony:/sbin/nologin polkitd:x:999:998:User for polkitd:/:/sbin/nologin yinzhengjie:x:1000:1000::/home/yinzhengjie:/bin/bash [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# cat /etc/passwd root:x:0:0:root:/root:/bin/bash bin:x:1:1:bin:/bin:/sbin/nologin daemon:x:2:2:daemon:/sbin:/sbin/nologin adm:x:3:4:adm:/var/adm:/sbin/nologin lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin sync:x:5:0:sync:/sbin:/bin/sync shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown halt:x:7:0:halt:/sbin:/sbin/halt mail:x:8:12:mail:/var/spool/mail:/sbin/nologin operator:x:11:0:operator:/root:/sbin/nologin games:x:12:100:games:/usr/games:/sbin/nologin ftp:x:14:50:FTP User:/var/ftp:/sbin/nologin nobody:x:99:99:Nobody:/:/sbin/nologin systemd-network:x:192:192:systemd Network Management:/:/sbin/nologin dbus:x:81:81:System message bus:/:/sbin/nologin polkitd:x:999:998:User for polkitd:/:/sbin/nologin sshd:x:74:74:Privilege-separated SSH:/var/empty/sshd:/sbin/nologin postfix:x:89:89::/var/spool/postfix:/sbin/nologin chrony:x:998:996::/var/lib/chrony:/sbin/nologin yinzhengjie:x:1000:1000::/home/yinzhengjie:/bin/bash [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# sort -t ":" -k 3 -n /etc/passwd root:x:0:0:root:/root:/bin/bash bin:x:1:1:bin:/bin:/sbin/nologin daemon:x:2:2:daemon:/sbin:/sbin/nologin adm:x:3:4:adm:/var/adm:/sbin/nologin lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin sync:x:5:0:sync:/sbin:/bin/sync shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown halt:x:7:0:halt:/sbin:/sbin/halt mail:x:8:12:mail:/var/spool/mail:/sbin/nologin operator:x:11:0:operator:/root:/sbin/nologin games:x:12:100:games:/usr/games:/sbin/nologin ftp:x:14:50:FTP User:/var/ftp:/sbin/nologin sshd:x:74:74:Privilege-separated SSH:/var/empty/sshd:/sbin/nologin dbus:x:81:81:System message bus:/:/sbin/nologin postfix:x:89:89::/var/spool/postfix:/sbin/nologin nobody:x:99:99:Nobody:/:/sbin/nologin systemd-network:x:192:192:systemd Network Management:/:/sbin/nologin chrony:x:998:996::/var/lib/chrony:/sbin/nologin polkitd:x:999:998:User for polkitd:/:/sbin/nologin yinzhengjie:x:1000:1000::/home/yinzhengjie:/bin/bash [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# sort -t ":" -k 3 -nr /etc/passwd #注意，"-r"选项表示降序，如果不加该选项表示升序排列。 yinzhengjie:x:1000:1000::/home/yinzhengjie:/bin/bash polkitd:x:999:998:User for polkitd:/:/sbin/nologin chrony:x:998:996::/var/lib/chrony:/sbin/nologin systemd-network:x:192:192:systemd Network Management:/:/sbin/nologin nobody:x:99:99:Nobody:/:/sbin/nologin postfix:x:89:89::/var/spool/postfix:/sbin/nologin dbus:x:81:81:System message bus:/:/sbin/nologin sshd:x:74:74:Privilege-separated SSH:/var/empty/sshd:/sbin/nologin ftp:x:14:50:FTP User:/var/ftp:/sbin/nologin games:x:12:100:games:/usr/games:/sbin/nologin operator:x:11:0:operator:/root:/sbin/nologin mail:x:8:12:mail:/var/spool/mail:/sbin/nologin halt:x:7:0:halt:/sbin:/sbin/halt shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown sync:x:5:0:sync:/sbin:/bin/sync lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin adm:x:3:4:adm:/var/adm:/sbin/nologin daemon:x:2:2:daemon:/sbin:/sbin/nologin bin:x:1:1:bin:/bin:/sbin/nologin root:x:0:0:root:/root:/bin/bash [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# seq 10 1 2 3 4 5 6 7 8 9 10 [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# seq 10 | sort -nr #按数字倒叙排列 10 9 8 7 6 5 4 3 2 1 [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# seq 10 | sort -R #随机排列 6 10 3 5 4 1 8 2 9 7 [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# seq 10 | sort -R| head -1 #模拟随机抽取一个数字 10 [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# seq 10 | sort -R| head -1 3 [root@node101.yinzhengjie.org.cn ~]# seq 10 | sort -R| head -1 6 [root@node101.yinzhengjie.org.cn ~]# seq 10 | sort -R| head -1 6 [root@node101.yinzhengjie.org.cn ~]# seq 10 | sort -R| head -1 7 [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# df Filesystem 1K-blocks Used Available Use% Mounted on /dev/mapper/VolGroup-lv_root 51474912 1449844 47387244 3% / devtmpfs 927056 0 927056 0% /dev tmpfs 938788 0 938788 0% /dev/shm tmpfs 938788 9112 929676 1% /run tmpfs 938788 0 938788 0% /sys/fs/cgroup /dev/sda1 487634 115872 342066 26% /boot /dev/mapper/VolGroup-lv_home 11778300 596844 10560096 6% /home tmpfs 187760 0 187760 0% /run/user/0 [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# df | tr -s ' ' '%' | cut -d "%" -f 5 | tr -dc '[0-9]\n' | sort -nr #对磁盘空间使用率进行排序 26 6 3 1 0 0 0 0 [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# uniq --help #查看该命令的帮助信息 Usage: uniq [OPTION]... [INPUT [OUTPUT]] Filter adjacent matching lines from INPUT (or standard input), writing to OUTPUT (or standard output). With no options, matching lines are merged to the first occurrence. Mandatory arguments to long options are mandatory for short options too. -c, --count prefix lines by the number of occurrences -d, --repeated only print duplicate lines, one for each group -D, --all-repeated[=METHOD] print all duplicate lines groups can be delimited with an empty line METHOD={none(default),prepend,separate} -f, --skip-fields=N avoid comparing the first N fields --group[=METHOD] show all items, separating groups with an empty line METHOD={separate(default),prepend,append,both} -i, --ignore-case ignore differences in case when comparing -s, --skip-chars=N avoid comparing the first N characters -u, --unique only print unique lines -z, --zero-terminated end lines with 0 byte, not newline -w, --check-chars=N compare no more than N characters in lines --help display this help and exit --version output version information and exit A field is a run of blanks (usually spaces and/or TABs), then non-blank characters. Fields are skipped before chars. Note: 'uniq' does not detect repeated lines unless they are adjacent. You may want to sort the input first, or use 'sort -u' without 'uniq'. Also, comparisons honor the rules specified by 'LC_COLLATE'. GNU coreutils online help: <http://www.gnu.org/software/coreutils/> For complete documentation, run: info coreutils 'uniq invocation' [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# cat f3.txt a b a aa bb bb bb ccc ccc ccc d eee eee eee eee eee a eee f [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# uniq f3.txt #该命令会默认删除前后相接重复的行 a b a aa bb ccc d eee a eee f [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# cat f3.txt a b a aa bb bb bb ccc ccc ccc d eee eee eee eee eee a eee f [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# uniq -c f3.txt #除了删除前后相接重复的行外，这里的"-c"选项还可以显示相邻行出现重复的频次 1 a 1 b 1 a 1 aa 3 bb 3 ccc 1 d 5 eee 1 a 1 eee 1 f [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# cat f3.txt a b a aa bb bb bb ccc ccc ccc d eee eee eee eee eee a eee f [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# uniq -c f3.txt | sort -nr #对相邻行之间出现对频次进行一个降序排列 5 eee 3 ccc 3 bb 1 f 1 eee 1 d 1 b 1 aa 1 a 1 a 1 a [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# cat f3.txt a b a aa bb bb bb ccc ccc ccc d eee eee eee eee eee a eee f [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# uniq -d f3.txt #只显示相邻行出现重复的行 bb ccc eee [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# uniq -d -c f3.txt 3 bb 3 ccc 5 eee [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# cat f3.txt a b a aa bb bb bb ccc ccc ccc d eee eee eee eee eee a eee f [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# uniq -u f3.txt #只显示相邻行没有出现重复的行 a b a aa d a eee f [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# ll total 20 drwxr-xr-x. 2 root root 4096 Oct 18 03:26 data -rw-r--r--. 1 root root 46 Oct 18 02:24 f1.txt -rw-r--r--. 1 root root 14 Oct 18 02:04 f2.txt -rw-r--r--. 1 root root 60 Oct 18 03:09 f3.txt -rw-r--r--. 1 root root 553 Oct 18 02:20 hadoop.txt [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# ll data/ total 12 -rw-r--r--. 1 root root 0 Oct 18 03:26 6.txt -rw-r--r--. 1 root root 0 Oct 18 03:26 7.txt -rw-r--r--. 1 root root 0 Oct 18 03:26 8.txt -rw-r--r--. 1 root root 46 Oct 18 03:25 f1.txt -rw-r--r--. 1 root root 14 Oct 18 03:25 f2.txt -rw-r--r--. 1 root root 60 Oct 18 03:25 f3.txt [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# ls /root/ > /tmp/root.log [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# ls /root/data/ > /tmp/data.log [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# cat /tmp/root.log /tmp/data.log | sort | uniq -d #统计2个目录出现文件名相同的行 f1.txt f2.txt f3.txt [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# sort /tmp/data.log /tmp/root.log | uniq -d f1.txt f2.txt f3.txt [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# ls /root/ /root/data/ -1 | sort | uniq -d #可以很轻松统计两个目录中出现同名的文件名 f1.txt f2.txt f3.txt [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# ls data f1.txt f2.txt f3.txt hadoop.txt [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# ls data/ 6.txt 7.txt 8.txt f1.txt f2.txt f3.txt [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# ls /root/ /root/data/ -1 | sort | uniq -u #取出两个目录中不同的文件列表 6.txt 7.txt 8.txt data hadoop.txt /root/: /root/data/: [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]#
运维面试题一：取出Nginx访问日志中"/var/log/access_log"中访问量Top 10. 参考案例：[root@node101.yinzhengjie.org.cn ~]# cut -d " " -f 1 /var/log/access_log | sort | uniq -c | sort -nr | head -n 10
运维面试题二:取出"login.txt"文件中用户登陆失败IP最高的Top 10.
参考案例:[root@node101.yinzhengjie.org.cn ~]# lastb -f login.txt | tr -s " " | cut -d " " -f 3 | sort | uniq -c | sort -nr | head
运维面试题三:取出"login.txt"文件中用户登陆失败尝试最多用户的Top 5.
参考案例:[root@node101.yinzhengjie.org.cn ~]# lastb -f login.txt | cut -d " " -f 1 | sort | uniq -c | sort -nr | head -5
3>.比较文件：diff(比较两个文件的区别，命令的输出被保存在一种叫做"补丁"的文件中)和patch(复制在其他文件中进行的改变，要谨慎使用)
[root@node101.yinzhengjie.org.cn ~]# diff --help #查看该命令的帮助信息 Usage: diff [OPTION]... FILES Compare FILES line by line. Mandatory arguments to long options are mandatory for short options too. --normal output a normal diff (the default) -q, --brief report only when files differ -s, --report-identical-files report when two files are the same -c, -C NUM, --context[=NUM] output NUM (default 3) lines of copied context -u, -U NUM, --unified[=NUM] output NUM (default 3) lines of unified context -e, --ed output an ed script -n, --rcs output an RCS format diff -y, --side-by-side output in two columns -W, --width=NUM output at most NUM (default 130) print columns --left-column output only the left column of common lines --suppress-common-lines do not output common lines -p, --show-c-function show which C function each change is in -F, --show-function-line=RE show the most recent line matching RE --label LABEL use LABEL instead of file name (can be repeated) -t, --expand-tabs expand tabs to spaces in output -T, --initial-tab make tabs line up by prepending a tab --tabsize=NUM tab stops every NUM (default 8) print columns --suppress-blank-empty suppress space or tab before empty output lines -l, --paginate pass output through 'pr' to paginate it -r, --recursive recursively compare any subdirectories found --no-dereference don't follow symbolic links -N, --new-file treat absent files as empty --unidirectional-new-file treat absent first files as empty --ignore-file-name-case ignore case when comparing file names --no-ignore-file-name-case consider case when comparing file names -x, --exclude=PAT exclude files that match PAT -X, --exclude-from=FILE exclude files that match any pattern in FILE -S, --starting-file=FILE start with FILE when comparing directories --from-file=FILE1 compare FILE1 to all operands; FILE1 can be a directory --to-file=FILE2 compare all operands to FILE2; FILE2 can be a directory -i, --ignore-case ignore case differences in file contents -E, --ignore-tab-expansion ignore changes due to tab expansion -Z, --ignore-trailing-space ignore white space at line end -b, --ignore-space-change ignore changes in the amount of white space -w, --ignore-all-space ignore all white space -B, --ignore-blank-lines ignore changes where lines are all blank -I, --ignore-matching-lines=RE ignore changes where all lines match RE -a, --text treat all files as text --strip-trailing-cr strip trailing carriage return on input -D, --ifdef=NAME output merged file with '#ifdef NAME' diffs --GTYPE-group-format=GFMT format GTYPE input groups with GFMT --line-format=LFMT format all input lines with LFMT --LTYPE-line-format=LFMT format LTYPE input lines with LFMT These format options provide fine-grained control over the output of diff, generalizing -D/--ifdef. LTYPE is 'old', 'new', or 'unchanged'. GTYPE is LTYPE or 'changed'. GFMT (only) may contain: %< lines from FILE1 %> lines from FILE2 %= lines common to FILE1 and FILE2 %[-][WIDTH][.[PREC]]{doxX}LETTER printf-style spec for LETTER LETTERs are as follows for new group, lower case for old group: F first line number L last line number N number of lines = L-F+1 E F-1 M L+1 %(A=B?T:E) if A equals B then T else E LFMT (only) may contain: %L contents of line %l contents of line, excluding any trailing newline %[-][WIDTH][.[PREC]]{doxX}n printf-style spec for input line number Both GFMT and LFMT may contain: %% % %c'C' the single character C %c'\OOO' the character with octal code OOO C the character C (other characters represent themselves) -d, --minimal try hard to find a smaller set of changes --horizon-lines=NUM keep NUM lines of the common prefix and suffix --speed-large-files assume large files and many scattered small changes --help display this help and exit -v, --version output version information and exit FILES are 'FILE1 FILE2' or 'DIR1 DIR2' or 'DIR FILE...' or 'FILE... DIR'. If --from-file or --to-file is given, there are no restrictions on FILE(s). If a FILE is '-', read standard input. Exit status is 0 if inputs are the same, 1 if different, 2 if trouble. Report bugs to: bug-diffutils@gnu.org GNU diffutils home page: <http://www.gnu.org/software/diffutils/> General help using GNU software: <http://www.gnu.org/gethelp/> [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# cat a.txt a b c [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# cat b.txt a bb ccc [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# diff a.txt b.txt #显示2个文件不同的行。 2,3c2,3 < b < c --- > bb > ccc [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# cat a.txt a b c [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# cat b.txt a bb ccc [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# diff -u a.txt b.txt #可以看到更加详细的对比 --- a.txt 2019-10-18 04:06:11.929873028 -0400 #下面带有"-"表示的是a.txt +++ b.txt 2019-10-18 04:07:04.243307997 -0400 #下面带有"+"表示的是b.txt @@ -1,3 +1,3 @@ a -b -c +bb +ccc [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# patch --help #查看该命令的帮助信息 Usage: patch [OPTION]... [ORIGFILE [PATCHFILE]] Input options: -p NUM --strip=NUM Strip NUM leading components from file names. -F LINES --fuzz LINES Set the fuzz factor to LINES for inexact matching. -l --ignore-whitespace Ignore white space changes between patch and input. -c --context Interpret the patch as a context difference. -e --ed Interpret the patch as an ed script. -n --normal Interpret the patch as a normal difference. -u --unified Interpret the patch as a unified difference. -N --forward Ignore patches that appear to be reversed or already applied. -R --reverse Assume patches were created with old and new files swapped. -i PATCHFILE --input=PATCHFILE Read patch from PATCHFILE instead of stdin. Output options: -o FILE --output=FILE Output patched files to FILE. -r FILE --reject-file=FILE Output rejects to FILE. -D NAME --ifdef=NAME Make merged if-then-else output using NAME. --merge Merge using conflict markers instead of creating reject files. -E --remove-empty-files Remove output files that are empty after patching. -Z --set-utc Set times of patched files, assuming diff uses UTC (GMT). -T --set-time Likewise, assuming local time. --quoting-style=WORD output file names using quoting style WORD. Valid WORDs are: literal, shell, shell-always, c, escape. Default is taken from QUOTING_STYLE env variable, or 'shell' if unset. Backup and version control options: -b --backup Back up the original contents of each file. --backup-if-mismatch Back up if the patch does not match exactly. --no-backup-if-mismatch Back up mismatches only if otherwise requested. -V STYLE --version-control=STYLE Use STYLE version control. STYLE is either 'simple', 'numbered', or 'existing'. -B PREFIX --prefix=PREFIX Prepend PREFIX to backup file names. -Y PREFIX --basename-prefix=PREFIX Prepend PREFIX to backup file basenames. -z SUFFIX --suffix=SUFFIX Append SUFFIX to backup file names. -g NUM --get=NUM Get files from RCS etc. if positive; ask if negative. Miscellaneous options: -t --batch Ask no questions; skip bad-Prereq patches; assume reversed. -f --force Like -t, but ignore bad-Prereq patches, and assume unreversed. -s --quiet --silent Work silently unless an error occurs. --verbose Output extra information about the work being done. --dry-run Do not actually change any files; just print what would happen. --posix Conform to the POSIX standard. -d DIR --directory=DIR Change the working directory to DIR first. --reject-format=FORMAT Create 'context' or 'unified' rejects. --binary Read and write data in binary mode. --read-only=BEHAVIOR How to handle read-only input files: 'ignore' that they are read-only, 'warn' (default), or 'fail'. -x NUM --debug=NUM Set internal debugging flags. -v --version Output version info. --help Output this help. Report bugs to <bug-patch@gnu.org>. [root@node101.yinzhengjie.org.cn ~]#
[root@node101.yinzhengjie.org.cn ~]# cat a.txt a b c [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# cat b.txt a bb ccc [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# diff -u a.txt b.txt > diff.log #我们将文件的不同之处保存到一个中间文件中 [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# rm -f b.txt #此时我们将“b.txt”文件删除掉 [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# patch -b a.txt diff.log #我们使用patch命令可以找回文件，"-b"参数表示对a.txt文件进行备份，因为我们使用patch命令基于diff.log文件恢复b.txt文件内容会覆盖a.txt文件内容。 patching file a.txt [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# ll total 12 -rw-r--r--. 1 root root 9 Oct 18 04:16 a.txt -rw-r--r--. 1 root root 6 Oct 18 04:06 a.txt.orig -rw-r--r--. 1 root root 126 Oct 18 04:14 diff.log [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# cat a.txt #这是原来"b.txt"文件内容 a bb ccc [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# cat a.txt.orig #这是原来"a.txt"文件内容的备份 a b c [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# mv a.txt b.txt [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# mv a.txt.orig a.txt [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# cat a.txt a b c [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]# cat b.txt a bb ccc [root@node101.yinzhengjie.org.cn ~]# [root@node101.yinzhengjie.org.cn ~]#
八.小试牛刀
1>.找出ifconfig “网卡名” 命令结果中本机的IPv4地址 2>.查出分区空间使用率的最大百分比值 3>.查出用户UID最大值的用户名、UID及shell类型 4>.查出/tmp的权限，以数字方式显示 5>.统计当前连接本机的每个远程主机IP的连接数，并按从大到小排序
当你的才华还撑不起你的野心的时候，你就应该静下心来学习。当你的能力还驾驭不了你的目标的时候，你就应该沉下心来历练。问问自己，想要怎样的人生。
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