Re: while loop break when sub call

The thread to date sounds like you are not posting enough information, and that you've scrubbed your example too much to effectively debug. Please read How do I post a question effectively?, in particular, make sure that you post self-contained code that shows the problem. What happens in the subroutine? Nothing that's been posted should be resetting the getgrent iterator, though if you invoke it in your subroutine, that could mess you up. Note that the one-liner

perl -E 'sub func {"@_"} while (($name) = getgrent){if ($name =~ /^som
+etext_(\w+)/){func($name,$1);say $name}}';
[download]

runs just as I would expect, with no infinite loop.

#11929 First ask yourself `How would I do this without a computer?' Then have the computer do it the same way.

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Re^2: while loop break when sub call by papillon (Initiate) on Jan 09, 2015 at 18:16 UTC
Your comment pointed my mistake. In the subroutine, I create a new group, that must be the source of the problem. Using an intermediate array solved the problem. One of those cause that is so evident that you don't see it	[reply]
Re^3: while loop break when sub call by locked_user sundialsvc4 (Abbot) on Jan 09, 2015 at 22:39 UTC
Yes, undoubtedly the creation of a new group broke the iterator. That sort of thing happens a lot, and it goes back to the underlying operating system primitives. For example, I’ve found that when iterating through files and directories in Microsoft Windows (regardless of language), you mustn’t create/remove files or directories while doing so. First complete the scan (e.g. of one complete subdirectory), then act upon/iterate through an in-memory list of the things that the scan finds, and all is well.