how to start from within my shell-script xterm which starts mplayer and plays the files that are the argument of the script

Question

What I want to do: Start my script with a list of files as arguments. From within my script I want to start xterm that starts mplayer with these files.

I tried several things. I call my script like this:

myscript.sh *

The files are named like

"aaa AAA"
"bbb BBB"
"ccc DDD"

(i.e. filenames with spaces) and are playable sounds, music or videos with mplayer.

This is what I tried

All of the following commands were written inside my script!

I tried:

1. The following works. Files are printed.

   ls -l $@
   

2. The following works. Files are printed.

   IFS='\n'
   ls -l $*
   

3. The following works. Files are printed. Strangely I do not need the IFS='\n' here. Why?

   xterm -e 'ls -l $*; read'
   

4. This does not find the files.

   FILES=$@
   ls -l $FILES
   

5. This does not find the files. Here all filenames are treated as one long filename. (???)

   IFS='\n'
   FILES=$@
   ls -l $FILES
   

6. This does not find the files.

   export FILES=$@
   ls -l $FILES
   

7. But the following works. Files are printed.

   IFS='\n'
   export FILES=$@
   ls -l $FILES
   

---

Now with mplayer.

1. This works.

   IFS='\n'
   export FILES=$@
   mplayer $FILES
   

2. This does not work. But why does number 2 for ls -l work then? Here mplayer exits printing it’s help as if I just start mplayer with no arguments.

   xterm -e 'mplayer $*; read'
   

3. This does not work. It fails for all the files with spaces in the filename.

   IFS='\n'
   FILES=$@
   xterm -e 'mplayer $FILES; read'
   

Question: How can I start mplayer from its own xterm with the files saved in the $FILES variable?

Answer 1

If you want to pass the arguments to your script to mplayer, in an xterm, this should work:

#!/bin/sh
xterm -e mplayer "$@"

This works because of how "$@" expands: one parameter per item. xterm does not attempt to interpret the arguments to the command in any way; it just passes them through.

If you need actually put your file list in a variable, your best bet is to use an array variable. For example:

#!/bin/bash
declare -a FILES
for f; do
    if [ -r "$f" ]; then
        FILES+=("$f")
    fi
done

xterm -e mplayer "${FILES[@]}"

The above filters the files to only pass ones which are readable. This is just an example, normally you'd not do this type of filtering. Also, typically, I'd use a lowercase variable name, unless I were planning on exporting it.

PS: Depending on what you're doing, are you aware of mplayer's -slave mode?