Change Parent Shell’s Working Directory Programmatically

bashcd-commandshell

I want to write some code to allow me switching to some directories that I usually go to. Say this program is mycd, and /a/very/long/path/name is the directory that I want to go to.

So I can simply type mycd 2 instead of cd /a/very/long/path/name. Here I assume mycd knows 2 refers to that /a/very/long/path/name . There might also be mycd 1, mycd 3, … etc.

The problem is I have to write mycd as a shell script and type . mycd 2 to do the desired thing because otherwise the script just get executed in a child script which doesn't change anything about the parent shell that I actually care about.

My question is:

can I do it without using source? because . mycd assumes mycd has to be a shell script and this might also introduce some functions that I don't want.
can I implement it in some other programming languages?

Best Answer

make mycd a function so the cd command executes in your current shell. Save it in your ~/.bashrc file.

function mycd {
    if (( $# == 0 )); then
        echo "usage: $FUNCNAME [1|2|3|...]"
        return
    fi
    case $1 in
        1) cd /tmp ;;
        2) cd /a/very/long/path/name ;;
        3) cd /some/where/else ;;
        *) echo "unknown parameter" ;;
    esac
}

Related Solutions

Bash CD – Change Directory by Just Typing the Directory’s Name

Bash: shopt -s autocd
Zsh: setopt autocd
tcsh: set implicitcd

Also, 'autojump' is a useful tool. Once installed it remembers directories so that you can type j abc and if you've visited abc before, say x/d/f/g/t/abc then it will cd to there!
https://github.com/joelthelion/autojump

Bash – Simplified navigation in terminal

With two functions in your .bashrc file, you can use the directory stack for some navigation

function down ()
{
  if [[ -z "$1" ]]
  then
   n=1
  else
   n=$1
  fi

  for ((i=0; i<$n; i++ ));
  do
      pushd .. > /dev/null
  done;
}
function up ()
{
  if [[ -z "$1" ]]
  then
   n=1
  else
   n=$1
  fi

  for ((i=0; i<$n; i++ ));
  do
      popd > /dev/null
  done;
#  dirs -c  # To clear directory on up motion
}

Where you can use down N and up N, respectively.

Sample usage:

~/tmp/bash/dir1/dir2/dir3$ down 4
~/tmp$ up 2
~/tmp/bash/dir1$ up 2
~/tmp/bash/dir1/dir2/dir3$ down 2
~/tmp/bash/dir1$ down 1
~/tmp/bash$ up 3
~/tmp/bash/dir1/dir2/dir3$

Of course, you cannot use up N before using down N. Unexpected things might happen, or error messages may appear.

Best Answer

Related Solutions

Bash CD – Change Directory by Just Typing the Directory’s Name

Bash – Simplified navigation in terminal

Related Question