Re^2: Unexpected termination on "print" (pipe)

Thanks for your reply tye. Much appreciated, especially given how deep these nodes get pushed with all the questions coming through.

I know in principle what $? is used for, but I could not find (nor does the documentation you point to) a list matching perl exit codes (or are they system error codes?) with reasons. Should I be looking at something like errno.h?

However your pointer to SIGPIPE was spot on. Installing a handler allowed me to deal with the error and continue execution.

Thanks again.

Comment on Re^2: Unexpected termination on "print" (pipe)

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Re^3: Unexpected termination on "print" (docs) by tye (Sage) on Aug 14, 2015 at 20:50 UTC
Should I be looking at something like errno.h? No, you should be reading the documentation that I already linked to: $?. - tye	[reply]
Re^4: Unexpected termination on "print" (docs) by mlawren (Sexton) on Aug 14, 2015 at 21:22 UTC
Hmm... perhaps you think I didn't read the documentation you linked to? I did, twice, but that didn't get me very far. Which either says something about my comprehension, or the quality of the documentation. $? is a perl variable. Presumably, in the case we are discussing, print/write to a closed pipe results in $? being set, and presumably that is also what perl ends up passing back to the shell, which shifts it by 8 and eventually I end up seeing it as an integer. How does the documentation for $? supposed to get me from the number 141 back to SIGPIPE? update: So it turns out the shell exit code is $? directly, and not shifted like I thought. Hence: `141 >> 8 = 0 141 & 127 = 13 141 & 128 = 128` [download] And now I see that I have something I can look up in signum.h.	[reply] [d/l]
Re^5: Unexpected termination on "print" (docs) by afoken (Chancellor) on Aug 14, 2015 at 22:27 UTC
Hmm... perhaps you think I didn't read the documentation you linked to? I did, twice, but that didn't get me very far. Then you seem to have a real problem reading the documentation. Read the first paragraph below `$?`, and especially its last sentence. This is the first paragraph: The status returned by the last pipe close, backtick (``) command, successful call to `wait()` or `waitpid()`, or from the `system()` operator. This is just the 16-bit status word returned by the traditional Unix `wait()` system call (or else is made up to look like it). Thus, the exit value of the subprocess is really (`$? >> 8`), and `$? & 127` gives which signal, if any, the process died from, and `$? & 128` reports whether there was a core dump. What part of it don't you understand? Alexander -- Today I will gladly share my knowledge and experience, for there are no sweeter words than "I told you so". ;-)	[reply] [d/l] [select]
Re^5: Unexpected termination on "print" (docs) by AnomalousMonk (Archbishop) on Aug 14, 2015 at 22:29 UTC
How does the documentation for $? ... So it turns out ... Since you did not find this info in the linked documentation, can you please, for the benefit of future Seekers of Wisdom, publish a link or some other reference to the documentation or source of information that you ultimately used? Give a man a fish: `<%-{-{-{-<`	[reply] [d/l]
Re^6: Unexpected termination on "print" (docs) by mlawren (Sexton) on Aug 15, 2015 at 10:41 UTC
Re^7: Unexpected termination on "print" (standard) by tye (Sage) on Aug 15, 2015 at 16:32 UTC


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