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Symfony Process component: argument substitution with curly braces

Here is a code:

$cmd_make_sprite = '/usr/bin/gm convert /path/thumbs/video{1..353}.jpg -append /path/thumbs/sprite.jpg';

$process = new Process($cmd_make_sprite);
$process->run();
echo $process->getErrorOutput();

When I run this snippet I see this output:

/usr/bin/gm convert: Unable to open file (/path/thumbs/video{1..353}.jpg) [No such file or directory].

I think it happens because video{1..353}.jpg substitution doesn't work and Symfony Process builder treats this as a regular file name, which doesn't exist of course.

I tried to make a sprite_wrapper.sh for it:

#!/bin/bash

$@

and use it like this:

$cmd_make_sprite = 'bash sprite_wrapper.sh /usr/bin/gm convert /path/thumbs/video{1..353}.jpg -append /path/thumbs/sprite.jpg';

$process = new Process($cmd_make_sprite);
$process->run();
echo $process->getErrorOutput();

and it works, but I'd like to have a more clean code than that.

Does anyone have some thoughts how to improve it? Thanks in advance.

Solution

  • As you perhaps have guessed, the {x..y} syntax only works in Bash. But the default shell of Process is typically /bin/sh, which may not be Bash. That's why your first attempt didn't work.

    The intermediary sprite_wrapper.sh is really ugly, and unnecessary. You can write like this:

    $cmd_make_sprite = 'bash -c "/usr/bin/gm convert /path/thumbs/video{1..353}.jpg -append /path/thumbs/sprite.jpg"';

    That is, you can pass Bash code to execute with bash using the -c "..." option.