Printing a message on the console when the user moves to specific directory

mohit052 · 05-13-2009, 01:27 AM

Hi all .
I want that the user whenever moves to the directory /home/user/someApp
He should get a alert message

example:

[demo@localhost ~]$cd /home/user/someApp
ALERT!!!
Please dont delete any files in the folder...
[demo@localhost /home/user/someApp]$

Thanks in advance ... :-)

colucix · 05-13-2009, 02:58 AM

You have to create your own function and put it in a file which is sourced whenever a user logins or opens a new shell session. It depends on the system you're running on (e.g. /etc/bashrc, /etc/profile, etc).

Code:

function cd() {
  builtin cd "$@" && test "$PWD" == "/home/$USER/someApp" && echo ALERT\!\!\! && echo Please don\'t delete any files in the folder...
}

Edit: I was wondering about the possibility a user changes directly to a directory that is some levels down /home/user/someApp. In that case the message is not displayed unless you change the function to match $PWD against a regular expression. The following is valid for Bash version 3 only (version 2 does not have the =~ operator). For older versions you have to change the code using grep:

Code:

function cd() {
  builtin cd "$@"
  if [[ "$PWD" =~ "^$HOME/someApp" ]]
  then
    echo ALERT\!\!\!
    echo Please don\'t delete any files in the folder...
  fi
}

For bash version 2, change the if statement to

Code:

if echo "$PWD" | grep -q $HOME/someApp