in reply to Check if module is installed

perldoc -f require : no option for checking the version on a module like with use.

I hate to ask a stupid question, but when troubleshooting I always start at the "is it plugged in" basics: Is Mail::Sendmail installed?

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Re^2: Check if module is installed
by DreamT (Pilgrim) on Nov 16, 2009 at 11:08 UTC
    Ok!
    No, It's not installed, the purpose was to create some "try/catch" code to catch the error if the module isn't installed, since the code is to be distributed to several machines.
[reply]
      You want string eval: 
      eval "use Some::Module 94.5";
 
if($@) {
  print "Oh noes, it's not installed!\n";
} else {
  ...
}

      [download]
[reply]
[d/l]
        Checking $@ is not an appropriate way to check if an eval failed. An eval can fail, but in the clean up (DESTROY for instance), something can unset $@.

        The only way to make sure an eval succeeded is to check its return value: 

        eval "use Some::Module 94.5; 1" or do {
    printf "Loading Some::Module failed: %s", $@ // "Unknown error";
    ...
};

        [download]
[reply]
[d/l]

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