perl die & exit values

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

Hi,

Can any one enlighten me why the exit values are different in below code snippet? One is exit(-1) & other is exit(EBADF).

user@ubuntu:~$ perl -e 'die "Hello"';echo $?
Hello at -e line 1.
255
user@ubuntu:~$ perl 
die "Hello"
Hello at - line 1.
user@ubuntu:~$ echo $?
9
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Re: perl die & exit values by Corion (Patriarch) on Feb 26, 2018 at 14:55 UTC
See the documentation of die: If an uncaught exception results in interpreter exit, the exit code is determined from the values of $! and $? with this pseudocode: `exit $! if $!; # errno exit $? >> 8 if $? >> 8; # child exit status exit 255; # last resort` [download] And likely, `$!` is set from some other operation that your script (or Perl) performed. So you can't rely on a specific exit code if your script `die`s. If you need something really specific, you could install your own handler via either an END block or a `$SIG{__DIE__}` handler (perlvar).	[reply] [d/l] [select]
Re^2: perl die & exit values by choroba (Cardinal) on Feb 26, 2018 at 15:36 UTC
> you can't rely on a specific exit code if your script dies What about setting $! just before you die? `$ perl; echo $? $!=42; die "Hello" __END__ Hello at - line 1. 42` [download] ($q=q:Sq=~/;[c](.)(.)/;chr(-\|\|-\|5+lengthSq)`"S\|oS2"`map{chr \|+ord }map{substrSq`S_+\|`\|}3E\|-\|`7**2-3:)=~y+S\|`+$1,++print+eval$q,q,a, [download]	[reply] [d/l] [select]