How can I change my tcsh prompt to show my current working directory?

Question

I am using tcshand I am looking for a way responsive working directory where I at least want to display the last folder name instead of getting full path.

Imagine my current working directory is :

  [user@hostname/home/us/Desktop/my/projects]

then I would like to display the prompt like this :

    [user@hostname projects] 

present I am using the .cshrc file in file I have written like this:

  alias setprompt 'set prompt="[suman@`hostname` `pwd`:~] $"'
  alias setprompt 'set prompt="${LightGreen}[${yellow}suman${Light}${LightPurple}@%m ${LightGreen}:~] ${yellow}$ ${end} "'

I don't have PS1 variable also and don't know what it does, and I would like to know the difference between .cshrc file and .bashrc file.

Answer 1

You can use:

set prompt = '[%n@%m %c]$ '

%n for the username, %m for the hostname up to the first ., and %c for the last directory part. There are a large number of such substitutions available, you can find a list of them in tcsh(1), duplicated below for convenience.

Using `pwd` won't work, because the cshrc file is read only once on shelll startup, not on every directory change.

I would like to know the difference between .cshrc file and .bashrc file.

The cshrc file is used by csh and tcsh, the bashrc file is used by bash. Although they serve the same purpose, they're different programs (like ~/.mozilla/firefox and ~/.config/chromium).

---

%/  The current working directory.
%~  The current working directory, but with one's  home  direc‐
    tory  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 `/<skipped>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 vari‐
    able) for normal users, `#' (or  the  second  character  of
    promptchars) for the superuser.
%{string%}
    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 cor‐
    rected 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.

Answer 2

As stated by Randall, set the precmd alias:

alias precmd 'set prompt = "`echo $cwd` %# "'

Make the change permanent:

cat >> .cshrc << 'EOF'

# Custom prompt
alias precmd 'set prompt = "`echo $cwd` %# "'
'EOF'

Answer 3

Edit: I had assumed that the question would be about bash, because it was tagged like that.

.cshrc is the configuration file for csh or tcsh, wheras .bashrc is the configuration file for, well, bash. Even if they serve a similar purpose, bash and csh are simply different programs, so the configuration for one will not necessarily work for the other.

So what you need to do is to put a line like this into your .bashrc

PS1='...\w$ '

where \w is the magic code which will be expanded to the current working directory, as you can look up in the bash's man page in section "Prompting".

A more complete example, taken from the default setting of Cygwin's bash package, can look like this:

PS1='\[\e]0;\w\a\]\n\[\e[32m\]\u@\h \[\e[33m\]\w\[\e[0m\]\n\$ '

It will be expanded to a prompt like this (but with colors, uuuh):

user@machine currentdir $