cshell环境中提示符设置

终端的提示符可以按如下设置：
set prompt = '[%n@%m %c]$ '
set prompt='[%m:%/]>>>'
%n：用户名
%m：主机名
%c：最后的目录.
使用 pwd无效, 因为cshrc文件在shell启动的时候是只读的，不是在每一次文件改变时都读取。
csh和tcsh使用cshrc文件，bash使用bashrc文件。

以下是tcshell常用的提示符设置选项：

option	description
%/	The current working directory.
%~	The current working directory, but with one's home directory represented by `~' and other users' home directories represented by `~user' as per Filename substitution.`~user' substitution happens only if the shell has already used `~user' in a pathname in the current session.
%c[[0]n], %.[[0]n]	The trailing component of the current working directory, or n trailing components if a digit n is given. If n begins with `0', the number of skipped components precede the trailing component(s) in the format `/trailing'. If the ellipsis shell variable is set, skipped components are represented by an ellipsis so the whole becomes `...trailing'. `~' substitution is done as in `%~' above, but the `~' component is ignored when counting trailing components.
%C	Like %c, but without `~' substitution.
%h, %!, !	The current history event number.
%M	The full hostname.
%m	The hostname up to the first `.'.
%S (%s)	Start (stop) standout mode.
%B (%b)	Start (stop) boldfacing mode.
%U (%u)	Start (stop) underline mode.
%t, %@	The time of day in 12-hour AM/PM format.
%T	Like `%t', but in 24-hour format (but see the ampm shell variable).
%p	The `precise' time of day in 12-hour AM/PM format, with seconds.
%P	Like `%p', but in 24-hour format (but see the ampm shell variable).
\c	c is parsed as in bindkey.
^c	c is parsed as in bindkey.
%%	A single `%'.
%n	The user name.
%N	The effective user name.
%j	The number of jobs.
%d	The weekday in `Day' format.
%D	The day in `dd' format.
%w	The month in `Mon' format.
%W	The month in `mm' format.
%y	The year in `yy' format.
%Y	The year in `yyyy' format.
%l	The shell's tty.
%L	Clears from the end of the prompt to end of the display or the end of the line.
%$	Expands the shell or environment variable name immediately after the `$'.
%#	`>' (or the first character of the promptchars shell variable) for normal users, `#' (or the second character of promptchars) for the superuser.
%	Includes string as a literal escape sequence. It should be used only to change terminal attributes and should not move the cursor location. This cannot be the last sequence in prompt.
%?	The return code of the command executed just before the prompt.
%R	In prompt2, the status of the parser. In prompt3, the corrected string. In history, the history string.

`%B', `%S', `%U' and `%{string%}' are available in only eight-bit-clean shells; see the version shell variable.
The bold, standout and underline sequences are often used to distinguish a superuser shell. For example,
> set prompt = "%m [%h] %B[%@]%b [%/] you rang? "
tut [37] [2:54pm] [/usr/accts/sys] you rang? _

If `%t', `%@', `%T', `%p', or `%P' is used, and noding is not set, then print DING!' on the change of hour (i.e, :00' min‐
utes) instead of the actual time.

Set by default to `%# ' in interactive shells.