1

Background:

This question is about using the cd command in a bash script or alias.

There is a related SO question here: Why doesn't "cd" work in a bash shell script?

Problem:

Suppose you have a bash program called "foopath" that sends a path to a directory to stdout when you pass in an argument, e.g., 

  $> /usr/bin/foopath 1998      ## returns /some/long/path/here/1998
  $> /usr/bin/foopath 80817     ## returns /totally/different/path/80817/files

The foopath program just does a lookup and returns the closest matching path it can find based on the argument the user passed in.

Question:

1) How would you construct a function and alias in your .bash_profile so that the user can:

  • 1a) type foo 1998 or foo 80817 (foopath command shortening goal)
  • 1b) change dir using cd foo 1998 or cd foo 80817 (change-directory goal)
  • 1c) change directory from the command prompt (not-just-subshell-only goal)

Pitfalls

Because of the goal in 1c above, this seemingly simple task is proving cumbersome. In other words, the function/alias should be usable interactively, just as shown in the example from the related SO post at Why doesn't "cd" work in a bash shell script?.

Community
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dreftymac
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2 Answers2

1

1a)

foo () {
    cd "$(foopath $1)"
}

1b)

cd () {
    case $1 in     
      (foo) builtin cd "$(foopath $2)";;
      (*)   builtin cd "$@";;
    esac
}

1c) Both 1a) and 1b) can be used interactively.

Jens
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1

The solution could be either

  1. by making the script a function instead

    function script() 
{
     cd "$(foopath "$*")"
}

  2. by using source script.sh (or . script.sh) instead, so the script runs in the calling shell

sehe
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