bash -c not working with newlines

zagzagel · 07-14-2010, 04:41 PM

Hi everyone,

I've been using Linux for almost an year and I can't believe how I survived so long without knowing it (so far only used wind..ughh can't finish saying it).

Anyhow, I'm using Ubuntu 10.04LTS on Openbox. Everything is working fine, but when I add keybindings at some point I need globbing so I do <execute>bash -c "application /path/to/args/*"</execute> to enable globbing. This however has a problem, I can't add newlines between the arguments, and sometimes it leads to really long lines that have to be wrapped.

So, finally, my question: Is there anyway to execute an application through openbox's keybindings with globbing enabled which allows me to add newlines between the programs arguments?
[EDIT]I'd prefer not to make my own program to apply globbing to the application nor create scripts, so if that's the only way you can find to solve this problem then I do not need you answear (not trying to act up, it's just that I can solve it that way too, but prefer a more elegant aproach)[/EDIT]

Best regards,
Raimundo Martins

Andrew Benton · 07-14-2010, 07:07 PM

Interesting question. I don't use Ubunut but I do use openbox and I have tweaked the keybindings a bit. Can you give me an example of the sort of command that would need to be split over more than one line?

zagzagel · 07-14-2010, 07:39 PM

Well, I basically use these keybindings to play music so something like

<keybind key="backslash"><action name="Execute"><execute>audacious
~/music/mars\ volta\,\ the/2003\ -\ de-loused\ in\ the\ comatorium/inertiatic\ esp.mp3
~/music/mars\ volta\,\ the/2009\ -\ octahedron/*
~/music/prodigy\,\ the/*/*
</execute></action></keybind>

I don't actually have the really long lines right now because... well.. I'd have a really long config file (and it would be pointless to post dozens of lines when they're just paths to personal filenames) but it would be something like this.

I tried:

<keybind key="backslash"><action name="Execute"><execute>bash -c "audacious \
~/music/mars\ volta\,\ the/2003\ -\ de-loused\ in\ the\ comatorium/inertiatic\ esp.mp3 \
~/music/mars\ volta\,\ the/2009\ -\ octahedron/* \
~/music/prodigy\,\ the/*/*"
</execute></action></keybind>

But it doesn't work. It starts audacious without any song and I get an output like:
bash: line 1: ~/music/mars\ volta\,\ the/2003\ -\ de-loused\ in\ the\ comatorium/inertiatic\ esp.mp3: permission denied

I'm checking on openbox's source code to see if I can add something to the parser to understand my folders and automatically add keybinds to them. Fun project for holidays, uh? :P

Thanks for your interest =)

Andrew Benton · 07-15-2010, 11:21 AM

Well if it was me I would just make an m3u playlist and set audacious as the default app to run the playlist, then when I click on the m3u playlist it would just work. However, as you want keybindings, not clicky clicky mouse clicking (I do understand), this works for me

Code:

    <keybind key="backslash">
      <action name="Execute">
        <execute>audacious \
        ~/save/share/music/Wilco\ \-\ Someone\ Else\'s\ Song.mp3
        ~/save/share/music/Thin\ Lizzy\ \-\ Borderline.m4a
        </execute>
      </action>
    </keybind>

zagzagel · 07-15-2010, 12:39 PM

Yes, that works for me too, but if you look closely you're not doing any globbing, ie you don't have something like:

Code:

audacious /play/everything/on/this/folder/*

But I see this is dragging along for too long, so I'll just call a C proggy to do the globbing instead of bash. And since bash calls ~/.bashrc on startup, it's probably most efficient this way. I'll post the C code of the program in case anyone stumbles upon this and needs my solution (still don't know what's wrong with bash and newlines which was the whole point of this question for me)

Code:

#include<stdio.h>
#include<stdlib.h>
#include<unistd.h>
#include<glob.h> //Nice header :) allows  for filename expansion just like shell. Oh, how I love Linux! x)

//#define DEBUG

int main(int argc, char *argv[])
{
        int i = 0;
        glob_t globber;

        if(argc > 1)
        {
                glob(argv[1], GLOB_NOCHECK | GLOB_TILDE | GLOB_BRACE, NULL, &globber);
                for(i = 2; i < argc; i++)
                        glob(argv[i], GLOB_NOCHECK | GLOB_TILDE | GLOB_BRACE | GLOB_APPEND, NULL, &globber);
        }

#if DEBUG
        for(i = 0; i < globber.gl_pathc; i++)
                printf("Arg %d: %s\n", i, globber.gl_pathv[i]);
#endif

        execvp(globber.gl_pathv[0], globber.gl_pathv);
        fprintf(stderr, "Globber: failed to execute application: %s\n", globber.gl_pathv[0]);
        return 1;
}

The first argument is "audacious" in this case. So to keybind that folder I'd have something like:

Code:

<execute>
globber audacious
/play/everything/on/this/folder/*
/and/this/folder/too/*
/accepts/braces/{folder1,folder2}/{01,02,05}*
</execute>

It's actually not that bad now that I did that. Maybe the kernel should support globbing by itself? :P Or maybe it's just bloat for a kernel.

If anyone would be kind enough to explain me what's the problem in executing bash that way though, I'd still love to hear it.