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Re: Check for another program availability

by afoken (Canon)
on Apr 11, 2021 at 09:29 UTC ( #11131104=note: print w/replies, xml ) Need Help??

in reply to Check for another program availability

If the program can be found in $ENV{'PATH'} when it is installed, then just trying to execute it will either succeed or fail, no need to search first. See system and exec.


Today I will gladly share my knowledge and experience, for there are no sweeter words than "I told you so". ;-)

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Re^2: Check for another program availability
by Radiola (Monk) on Apr 14, 2021 at 06:20 UTC

    Iíll sometimes do this as an explicit pre-flight check. If so, itís either because:

    1. I use this program deep in the code and I donít want to have to unroll a bunch of state (or fail and leave a broken mess) if I get halfway through and then find a critical external program is missing.

    2. I want to be unusually user-friendly for a Unix program. Seriously, sometimes the failure that results ďnaturallyĒ is misleading and will leave the user (usually me) scratching their head and having to troubleshoot. I can save them (myself) a bunch of time if I simply tell them (me) what's wrong.

    I agree thereís no point to checking for availability on the line before you try to run the program; you might as well just process the error from system or whatever.

    – Aaron
    Preliminary operational tests were inconclusive. (The damn thing blew up.)

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