Make Spreadsheet::ParseXLSX be quiet about errors

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

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Re: Make Spreadsheet::ParseXLSX be quiet about errors ($SIG{__WARN__} ) by LanX (Saint) on Aug 18, 2022 at 15:42 UTC
> How can I grab all erorrs to some variable without polluting stderr? `eval {BLOCK}` is only catching fatal errors, either thrown with `die` or from inside perl. But these seem to come from `warn` One way is to locally use a `%SIG` -handler. DEMO: `> perl -de0 ... DB<173> eval { local $SIG{__WARN__} = sub { die $_[0] }; warn "bla" +} or print "<<<$@>>>" <<<bla at (eval 197)[c:/nonBKU/strawberry-perl-5.32.1.1-64bit-portable +/perl/lib/perl5db.pl:738] line 2. >>> DB<174>` [download] There is also a pragma for this redirection - `use warnings FATAL =>"all";` ° But with a handler you can also choose to save the warnings to another variable separate from fatals. FWIW: Another approach would be to locally redirect STDERR to a var... Cheers Rolf _{(addicted to the Perl Programming Language :) Wikisyntax for the Monastery} °) updated see https://perldoc.perl.org/warnings#Fatal-Warnings for more	[reply] [d/l] [select]
Re^2: Make Spreadsheet::ParseXLSX be quiet about errors ($SIG{__WARN__} ) by leszekdubiel (Scribe) on Aug 18, 2022 at 18:42 UTC
https://stackoverflow.com/a/71683833 #!/usr/bin/perl use warnings; use strict; print STDERR "STDERR is on.\n"; my ($stderr_fh, $err_msg_ref) = suppress_std_err(); print "STDERR is now off and error messages are being suppressed and s +aved.\n"; print STDERR "I'm an error message.\n"; restore_std_err($stderr_fh); print STDERR "STDERR is back on\n"; print "Errors reported while STDERR was off: $$err_msg_ref\n"; #Saves STDERR in filehandle then turns it off. #Any error messages that occur while STDERR is off are stored for safe +keeping. sub suppress_std_err { my $suppressed_std_error_messages; open (my $saved_std_err_fh, ">&", STDERR); close STDERR; open (STDERR, ">", \$suppressed_std_error_messages); return ($saved_std_err_fh, \$suppressed_std_error_messages); } #Restores STDERR from saved filehandle. sub restore_std_err { my $old_std_err_fh = shift; close STDERR; open (STDERR, ">&", $old_std_err_fh); } [download]	[reply] [d/l]
Re^3: Make Spreadsheet::ParseXLSX be quiet about errors ( STDERR redirection ) (UPDATED) by LanX (Saint) on Aug 18, 2022 at 19:31 UTC
Yeah, but why? Redirecting STDERR is a tricky thing, there are long perldocs on this issue, and I'm not too confident about portability here. And you loose the ability to just selectively silence known `warnings`, while still being alarmed by unknown issues. So you will need to parse that variable afterwards. If you really want to capture all errors indiscriminately, better `use warnings FATAL => 'all'` inside eval (hence only for that lexical scope) Cheers Rolf _{(addicted to the Perl Programming Language :) Wikisyntax for the Monastery} UPDATE well, ok. One advantage of redirecting STDERR is that `print STDERR` will also be caught. But the errors you've shown most certainly come from some `Carp` routines. (FWIW you might alsow want to look into `Carp` for silencing advice)	[reply] [d/l] [select]
Re: Make Spreadsheet::ParseXLSX be quiet about errors by kcott (Archbishop) on Aug 19, 2022 at 08:15 UTC
G'day leszekdubiel, "open() - Duping filehandles" explains how you can do this. Here's some example code (`stderr_test.pl`): `#!/usr/bin/env perl use strict; use warnings; use autodie; use Spreadsheet::ParseXLSX; my $original_stderr; eval { open $original_stderr, '>&', \STDERR; open STDERR, '>&', \STDOUT; Spreadsheet::ParseXLSX->new->parse('invalid.xlsx'); 1; } or do { my $err = $@; print $err; }; open STDERR, '>&', $original_stderr; warn "Now back to normal STDERR\n";` [download] I set up a clean directory to show how this works. ken@titan ~/tmp/pm_11146229 $ ls -l total 1 -rw-r--r-- 1 ken None 0 Aug 19 17:09 invalid.xlsx -rwxr-xr-x 1 ken None 380 Aug 19 18:10 stderr_test.pl ken@titan ~/tmp/pm_11146229 $ ./stderr_test.pl > stdout.out 2> stderr.out ken@titan ~/tmp/pm_11146229 $ ls -l total 6 -rw-r--r-- 1 ken None 0 Aug 19 17:09 invalid.xlsx -rw-r--r-- 1 ken None 26 Aug 19 18:11 stderr.out -rwxr-xr-x 1 ken None 380 Aug 19 18:10 stderr_test.pl -rw-r--r-- 1 ken None 1105 Aug 19 18:11 stdout.out ken@titan ~/tmp/pm_11146229 $ cat stdout.out format error: file is too short at /home/ken/perl5/perlbrew/perls/perl-5.36.0/lib/site_perl/5.36.0/Ar +chive/Zip/Archive.pm line 1031. Archive::Zip::Archive::_findEndOfCentralDirectory(Archive::Zip +::Archive=HASH(0x8000b79b0), IO::File=GLOB(0x800099368)) called at /h +ome/ken/perl5/perlbrew/perls/perl-5.36.0/lib/site_perl/5.36.0/Archive +/Zip/Archive.pm line 761 Archive::Zip::Archive::readFromFileHandle(Archive::Zip::Archiv +e=HASH(0x8000b79b0), IO::File=GLOB(0x800099368), "invalid.xlsx") call +ed at /home/ken/perl5/perlbrew/perls/perl-5.36.0/lib/site_perl/5.36.0 +/Archive/Zip/Archive.pm line 729 Archive::Zip::Archive::read(Archive::Zip::Archive=HASH(0x8000b +79b0), "invalid.xlsx") called at /home/ken/perl5/perlbrew/perls/perl- +5.36.0/lib/site_perl/5.36.0/Spreadsheet/ParseXLSX.pm line 63 Spreadsheet::ParseXLSX::parse(Spreadsheet::ParseXLSX=HASH(0x80 +17a9b88), "invalid.xlsx") called at ./stderr_test.pl line 14 eval {...} called at ./stderr_test.pl line 17 Can't open file 'invalid.xlsx' as a zip file at /home/ken/perl5/perlbr +ew/perls/perl-5.36.0/lib/site_perl/5.36.0/Spreadsheet/ParseXLSX.pm li +ne 63. ken@titan ~/tmp/pm_11146229 $ cat stderr.out Now back to normal STDERR ken@titan ~/tmp/pm_11146229 $ [download] — Ken	[reply] [d/l] [select]
Re: Make Spreadsheet::ParseXLSX be quiet about errors by NERDVANA (Priest) on Aug 20, 2022 at 13:29 UTC
Before attempting to redirect STDERR on your own, I would suggest a module like Capture::Tiny `my ($stdout, $stderr, @result) = capture { eval { Spreadsheet::ParseXLSX->new->parse("/tmp/invalid.xlsx") } };` [download]	[reply] [d/l]

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