Re: checking for utilities/applications in the PATH

> i am trying to do a simple check for archiving utilities (zip, unzip, > ...), to make sure they exist within the PATH, and are executable by > PHP. > > i could not find a better way to do this through php, so i went ahead > and did an > > exec('which ' . $utility, $output, $return_value); > > then, i check the $return_value for a non-zero value, which would > indicate that the utility was not found. using GNU/Linux this seems to > work fine, but i wouldn't mind keeping my work cross-platform. > > so, my question is, is there a better way to do this? If you don't want to use the shell, you can check the $_SERVER['PATH'] environment variable. On my (linux) system it looks like "sbin:/usr/sbin:/bin:/usr/bin:/usr/X11R6/bin", so you could explode() that on ':' and then cycle through the files in each directory using readdir(), checking each with is_executable(). You could also just check the output of your exec() call - it should be the full path of the executable you're looking for. An empty return would imply that there isn't a matching executable. I think which always returns just the first match, since it's meant to show what would get called if you were to use that command. Personally I love using exec() to make php behave like bash at times, but posts on this list from pparently knowledgeable people occasionally imply that it's not the best/fastest/most stable method to use, so I try not to. -mike. --------------------------------------------------------------------- michal migurski- contact info and pgp key: sf/ca http://mike.teczno.com/contact.html