2013 年 9月 16 日随笔档案 - wjshan0808

2013年9月16日

摘要： 1 user commands2 system calls3 library functions4 special files5 file formats6 games7 conventions and miscellany8 administration and privileged commands这些只能有root执行阅读全文

posted @ 2013-09-16 23:12 wjshan0808 阅读(135) 评论(0) 推荐(0)

CentOS 的命令链接符“;”

摘要： ";" 用于在一行中输入多个命令，执行顺序=输入顺序。For instance：$ ls -a;cd Music 阅读全文

posted @ 2013-09-16 22:47 wjshan0808 阅读(1238) 评论(0) 推荐(0)

'printf' Function

摘要： printf is not part of the C language; there is no input or output defined in C itself.printf is just a useful function from the standard library of functions that are normally accessible to C programs.The behaviour of printf is defined in the ANSI standard,(美国国家标准协会 American National Standards Insti 阅读全文

posted @ 2013-09-16 13:42 wjshan0808 阅读(227) 评论(0) 推荐(0)

'%' For instance '%d'

摘要： with each % indicating where one of the other (second, third, ...) arguments is to be substituted, and in what form itis to be printed. For instance, %d specifies an integer argumentaugment each %dFor Instanceprintf("%3d'F%6d'C\n",Fahrenheit,Celsius);to print the first number of ea 阅读全文

posted @ 2013-09-16 13:31 wjshan0808 阅读(280) 评论(0) 推荐(0)

"Celsius=5/9*(Fahrenheit-32)" and "Celsius=5*(Fahrenheit-32)/9 "

摘要： The reason for multiplying by 5 and dividing by 9 instead of just multiplying by 5/9 is that in C, as in many otherlanguages, integer division truncates: any fractional part is discarded. Since 5 and 9 are integers. 5/9 would betruncated to zero and so all the Celsius temperatures would be reported 阅读全文

posted @ 2013-09-16 13:20 wjshan0808 阅读(368) 评论(0) 推荐(0)

Data types 'int' and 'float'

摘要： The type int means that the variables listed are integers; by contrast with float, which means floating point,i.e., numbers that may have a fractional part. The range of both int and float depends on the machine you areusing; 16-bits ints, which lie between -32768 and +32767, are common, as are 32-b 阅读全文

posted @ 2013-09-16 11:37 wjshan0808 阅读(208) 评论(0) 推荐(0)

escape sequence "\c"

摘要： #include int main(){ printf("Hello World !\c"); return 0;}[10:40:36@wjshan0808 ~/Documents/C Program]$ gcc printf.cprintf.c:4:9: warning: unknown escape sequence '\c'[10:41:52@wjshan0808 ~/Documents/C Program]$ g++ printf.cprintf.c: In function ‘int main()’:printf.c:4: warning: unk 阅读全文

posted @ 2013-09-16 10:46 wjshan0808 阅读(963) 评论(0) 推荐(0)

#include <stdio.h>

摘要： The first line of the C program#include tells the compiler to include information about the standard input/output library. 阅读全文

posted @ 2013-09-16 09:42 wjshan0808 阅读(367) 评论(0) 推荐(0)