Can I get the absolute path to the current script in KornShell?

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,

Solution 1

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 )

Solution 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..

Solution 3

Well it took me a while but this one is so simple it screams.

_SCRIPTDIR=$(cd $(dirname $0);echo $PWD)

since the CD operates in the spawned shell with $() it doesn't affect the current script.

Solution 4

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

readlink -f "$0"

Solution 5

The variable $RPATH contains the relative path to the real file or the real path for a real file.

CURPATH=$( cd -P -- "$(dirname -- "$(command -v -- "$0")")" && pwd -P )

CURLOC=$CURPATH/`basename $0`

if [ `ls -dl $CURLOC |grep -c "^l" 2>/dev/null` -ne 0 ];then

    ROFFSET=`ls -ld $CURLOC|cut -d ">" -f2 2>/dev/null`

    RPATH=`ls -ld $CURLOC/$ROFFSET 2>/dev/null`

else

    RPATH=$CURLOC

fi

echo $RPATH

View more solutions

Comments

[brabster]

thanks for the $0 tip, what's readlink? doesn't seem to be on my system

[brabster]

Hmmm need something totally within ksh, no dependencies. Thanks though

[soulmerge]

I'm afraid that won't be possible - unless ksh has a possibility I am not aware of for interacting with the file system. What's your OS?

[Henk Langeveld]

$0 refers to the name of the command as it was invoked, and does not need to refer to a file system object.

[synthesizerpatel]

Great answer - I was hoping this would also work if you source the script i.e. '. /some/script.sh' but it doesn't.

[Mat M]

@synthesizerpatel: In ksh93, you have ${.sh.file} which also works for sourced files.

[Tom Quarendon]

As pointed out by Gruik, this doesn't work if there is a symbolic link to the shell script itself. So if you link the command into, say, /usr/bin, then __REAL_SCRIPTDIR will return /usr/bin, which is (most likely) not what you want. You do apparently need readlink for this

[Tom Quarendon]

This does appear to be the only method available that copes with the situation of a symlink to the script itself, horrible though it is.

[andreee]

This answer should be incorporated into the accepted one. I was struggling for half an hour sourcing my ksh script until I realized that I need $_.