Can I get the absolute path to the current script

Question

Is it possible to find out the full path to the script that is currently executing in KornShell (ksh)?

i.e. if my script is in /opt/scripts/myscript.ksh, can I programmatically inside that script discover /opt/scripts/myscript.ksh ?

Thanks,

Answer 1

This is what I did:

if [[ $0 != "/"* ]]; then
  DIR=`pwd`/`dirname $0`
else
  DIR=`dirname $0`
fi

Answer 2

In korn shell, all of these $0 solutions fail if you are sourcing in the script in question. The correct way to get what you want is to use $_

$ cat bar

echo dollar under is $_
echo dollar zero is $0

$ ./bar

dollar under is ./bar
dollar zero is ./bar

$ . ./bar
dollar under is bar
dollar zero is -ksh

Notice the last line there? Use $_. At least in Korn. YMMV in bash, csh, et al..

Answer 3

How the script was called is stored in the variable $0. You can use readlink to get the absolute file name:

readlink -f "$0"

Answer 4

I upgraded the Edward Staudt's answer, to be able to deal with absolute-path symbolic links, and with chains of links too.

DZERO=$0
while true; do
  echo "Trying to find real dir for script $DZERO"
  CPATH=$( cd -P -- "$(dirname -- "$(command -v -- "$DZERO")")" && pwd -P )
  CFILE=$CPATH/`basename $DZERO`
  if [ `ls -dl $CFILE | grep -c "^l" 2>/dev/null` -eq 0 ];then
    break
  fi
  LNKTO=`ls -ld $CFILE | cut -d ">" -f2 | tr -d " " 2>/dev/null`
  DZERO=`cd $CPATH ; command -v $LNKTO`
done

Ugly, but works... After run this, the path is $CPATH and the file is $CFILE

Answer 5

Using $_ provides the last command.

>source my_script

Works if I issue the command twice:

>source my_script
>source my_script

If I use a different sequence of commands:

>who
>source my_script

The $_ variable returns "who"

Answer 6

You could use:

## __SCRIPTNAME - name of the script without the path
##
typeset -r __SCRIPTNAME="${0##*/}"

## __SCRIPTDIR - path of the script (as entered by the user!)
##
__SCRIPTDIR="${0%/*}"

## __REAL_SCRIPTDIR - path of the script (real path, maybe a link)
##
__REAL_SCRIPTDIR=$( cd -P -- "$(dirname -- "$(command -v -- "$0")")" && pwd -P )