Incase you didn't notice in the first post using grep, the -x function tests whether a file is executable. Like so: 
if ( -x '/path/to/file' ) {
    # file is executable, run it
    system('/path/to/file');
} else {
    # whatever
    system('/run/something/else');
}

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In reply to Re: checking external program for availability? by elwarren
in thread checking external program for availability? by bcrowell2

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