using if in bash script to check if prog exists

karuna-bdc · 06-21-2009, 07:08 AM

i have this script i wrote to use in nautilus to play mp3s in mplayer just for shell script practice, and it dosen't seem to work if i put an if routine in it to check that mplayer is executable and exists.

#!/bin/bash

if [-x mplayer] then
mplayer $NAUTILUS_SCRIPT_SELECTED_FILE_PATHS
fi

but if i take out the test:

#!/bin/bash

mplayer $NAUTILUS_SCRIPT_SELECTED_FILE_PATHS

It works...
what am i doing wrong with the if check?

H_TeXMeX_H · 06-21-2009, 07:20 AM

You can do:

Code:

if which mplayer
then
  mplayer $NAUTILUS_SCRIPT_SELECTED_FILE_PATHS
fi

karuna-bdc · 06-21-2009, 07:25 AM

That works, thanks

but what was wrong with the previous code?

H_TeXMeX_H · 06-21-2009, 07:36 AM

Well, you need the full path to mplayer. If you run 'which mplayer' it will give you the full path.

if [-x /usr/bin/mplayer] then

colucix · 06-21-2009, 07:38 AM

Quote:

Originally Posted by karuna-bdc

but what was wrong with the previous code?

If you do if [ -x mplayer ] you look for an executable just in the current directory, whereas the which command tells if you have the executable in any directory included in your PATH.

karuna-bdc · 06-21-2009, 01:37 PM

ahhh, that makes sense. Thanks

thats one of the wonderful things about learning linux - the community is loadsa help

chrism01 · 06-21-2009, 07:23 PM

NB in your orig code, you had no spaces around the '[', ']'. That would be a syntax error.