altering cd command, can it be done?

glingon · 10-28-2004, 01:00 PM

This may be more of a unix question, but I'll give it a go anyway. I'm using linux boxes running RedHat 9. the shell - Konsole in RedHat uses bash, knowing this is important.. My goal is to change the command prompt to look alot cooler than I thought the regular one did. I've acheived this:

<MyName><~> 5566#

through changing my .bashrc file at PS1= to say this:

PS1="<MyName><\w> \!# "

\w being current working directory.

This would have been enough, however there is the problem of using the cd (change directory) command. The problem being every time you change directory it prints the working directory. Why is this a problem, because the current directory is already being printed, I really don't need it printed twice. My question is now, can I somehow change the cd command to not print the working directory? Thanks in advance for responses

trickykid · 10-28-2004, 01:09 PM

That's not a problem with your cd command nor can it be fixed, as it has no idea what type of PS? type input you've customized for yourself. I don't know an easy way around this but it sounds like this would still be a hack for your PS1 environment setting for your user.

acid_kewpie · 10-28-2004, 01:11 PM

kshell? you mean ksh? ksh doesn't use bash... they are both shells, they don't use each other. and cd in bash doesn't print the current directory.

ranger_nemo · 10-28-2004, 01:18 PM

If you comment out the PS1= line in your .bashrc, and re-login, does it still print the pwd?

I can only think it is something else that is doing it. Do you have an alias for cd? Do you have a script named cd somewhere in a directory in your path?

bigrigdriver · 10-28-2004, 02:23 PM

Perhaps a thorough read of the bashprompt howto would give you ideas of how to customize the prompt.

glingon · 10-29-2004, 07:47 AM

Sorry about the thing about Kshell, i was just looking at the window title Shell - Konsole and thats what came out. I've overviewed the bashprompt howto and it doesn't look like it's going to help me.

My main question here is with the cd command. I've still not found a way to alter this so that it doesn't print the working directory on the next line after you type the command. Someone posted that cd does not do this, but I'm sitting here right now changing directories and its printing the working directory after I use cd.

Any direction would be great.

mAineAc · 10-29-2004, 08:11 AM

type 'alias' at the command line and see if cd has an alias that is doing this. Some distros will do this to make them more user friendly. Like some will have 'rm' alias as 'rm -i' so that it always asks if your sure you want to delete the file.

glingon · 10-29-2004, 09:29 AM

Nope, cd itself does not have an alias, however... that may be the solution to my problem, could anyone help me with creating and alias for the cd command that does not pwd?

glingon · 11-01-2004, 03:04 PM

Alright, not that you guys don't know any >8 ) . But i went and asked my university unix guru and he gave me the answer. You have to alias the cd command. you use this:

alias cd="cd $1 < /dev/null"

there... its useful.

KwajKeith · 11-24-2004, 08:47 PM

On Fedora, bash has trouble with alias cd="cd $1 < /bin/null". It can't perform the cd.

On csh or tcsh shells, on SGI unix, the command:
alias cd 'chdir \!* && set prompt="`hostname -s`:${LOGNAME}:`dirs`>'

works to give a prompt like Compter2:JJ:/home>

The prompt can be edited to give any combination of information the user wants to see. The ability to do this is facilitated by having the synonym for cd (chdir) in the builtin commands for the shell. This allows overloading the cd command. In bash, that is harder to do. cd does not normally print the directory again. You may have an overriding alias or two happening.

Hope this helps.