Re^2: 'do' command is dead? Surely not?

in reply to Re: 'do' command is dead? Surely not?
in thread 'do' command is dead? Surely not?

Thanks haukex - swift reply!

What, me, not using strict and warnings? ;-) Have changed 'test.pl' to the following:

use strict;
use warnings;

print "Hello world!\n";

my $file='test-response.pl';

unless (my $return = do $file) {
    warn "couldn't parse $file: $@" if $@;
    warn "couldn't do $file: $!"    unless defined $return;
    warn "couldn't run $file"       unless $return;
}

print "Did that work?\n";
[download]

Output is now

Hello world!
couldn't do test-response.pl: No such file or directory at test.pl lin
+e 10.
couldn't run test-response.pl at test.pl line 11.
Did that work?
[download]

The file 'test-response.pl' is certainly there.... (the files are on my desktop and I'm calling them from a command prompt having changed directory to the desktop, by the way).

Comment on Re^2: 'do' command is dead? Surely not? Select or Download Code

Replies are listed 'Best First'.
Re^3: 'do' command is dead? Surely not? by Eily (Monsignor) on May 19, 2017 at 14:24 UTC
You can check perl's current directory with Cwd (no matter how unlikely it seems for something to be the cause of a defect, if you're stuck, it's better to check than "just know"). You can also check which files .pl perl sees in the current folder with: `use Data::Dump qw( pp ); pp <*.pl>;` [download] I used Data::Dump instead of a simple print, because it will explicitly display characters that might go otherwise unnoticed. If you don't want to install it, you can use Data::Dumper and set $Data::Dumper::Useqq to 1	[reply] [d/l]
Re^3: 'do' command is dead? Surely not? by KurtZ (Friar) on May 19, 2017 at 14:28 UTC
do docs say "searches the @INC", so maybe check if "." is missing.	[reply]
Re^4: 'do' command is dead? Surely not? by davido (Cardinal) on May 19, 2017 at 14:38 UTC
Recent versions of Perl (v5.24.1+) removed '`.`' from `@INC`, so this is probably right on the mark. If the OP is using a recent enough Perl version it will not look in the dot path unless something like this happens: `use lib '.';` [download] Though that is subject to the challenges that the `dot` path has always faced. It would be better to do something like this: `use FindBin; use lib "$FindBin::Bin/../lib"; # Or whatever is accurate for this scr +ipt's needs.` [download] This eliminates sensitivity to where the script was invoked from. See also: FindBin, lib, and perl5241delta. Dave	[reply] [d/l] [select]
Re^5: 'do' command is dead? Surely not? by haukex (Archbishop) on May 19, 2017 at 16:27 UTC
Based on this post by the OP it sounds like this is the problem! Just to add a little info: Unfortunately the 5.24.1 doc is not up on http://perldoc.perl.org yet, so here is the link to the source. It seems that do's mechanism of searching `@INC` was impacted by this change - some interesting further reading for the curious is in the P5P threads The tricky issue of do() and [perl #131069] do file: Add './' in additional cases. Update: So as far as I understand it, the issue might be improved upon in v5.26 when that gets released.	[reply] [d/l]
Re^6: 'do' command is dead? Surely not? by ACI (Acolyte) on May 19, 2017 at 17:13 UTC
Re^5: 'do' command is dead? Surely not? by syphilis (Archbishop) on May 20, 2017 at 09:49 UTC
Recent versions of Perl (v5.24.1+) removed '.' from @INC I knew this is coming for 5.26.0+ ... but backporting it before 5.26.0 is released seems rather extraordinary to me. For the OP's case, I think `do './test-response.pl';` [download] is sufficient. Cheers, Rob	[reply] [d/l]
Re^5: 'do' command is dead? Surely not? by ACI (Acolyte) on May 19, 2017 at 14:57 UTC
Intriguing, though a bit technical for me to grasp. I update the OS religiously, and this might have been a trigger. Currently seem to be on Perl v5.24.1.	[reply]
Re^5: 'do' command is dead? Surely not? by KurtZ (Friar) on May 19, 2017 at 14:53 UTC
Recent versions of Perl (v5.24.1+) removed '.' from @INC, Ehm , why?	[reply]
Re^6: 'do' command is dead? Surely not? by tobyink (Canon) on May 19, 2017 at 15:09 UTC
Re^7: 'do' command is dead? Surely not? by KurtZ (Friar) on May 19, 2017 at 15:53 UTC
Re^7: 'do' command is dead? Surely not? by Anonymous Monk on May 19, 2017 at 17:58 UTC
Some notes below your chosen depth have not been shown here
Re^6: 'do' command is dead? Surely not? by dasgar (Priest) on May 19, 2017 at 18:24 UTC
Re^7: 'do' command is dead? Surely not? by KurtZ (Friar) on May 19, 2017 at 21:44 UTC
Re^3: 'do' command is dead? Surely not? by haukex (Archbishop) on May 19, 2017 at 14:25 UTC
The file 'test-response.pl' is certainly there... Not to Perl it seems... I would investigate this further. For example, try things like `print -e $file ? "exists\n" : "doesn't exist\n";`, `use Cwd; print getcwd, "\n";`, or `my $file='/absolute/path/to/test-response.pl';`. Also, what version of Perl are you using?	[reply] [d/l] [select]
Re^4: 'do' command is dead? Surely not? by ACI (Acolyte) on May 19, 2017 at 14:45 UTC
Thanks both, nice tips. Can confirm that both 'test.pl' and 'test-response.pl' are recognised in the following tests `my @files=(); @files=glob(''); print join("\n",@files),"\n";` [download] and `use Data::Dump qw( pp ); pp <.pl>;` [download] and that this test yields '/home/Andy/Desktop' as expected `use Cwd; my $dir = getcwd; print "$dir\n";` [download] Finally, %inc contains: warnings/register.pm /usr/share/perl/5.24/warnings/register.pm overload.pm /usr/share/perl/5.24/overload.pm vars.pm /usr/share/perl/5.24/vars.pm Cwd.pm /usr/lib/x86_64-linux-gnu/perl/5.24/Cwd.pm Exporter.pm /usr/share/perl/5.24/Exporter.pm overloading.pm /usr/share/perl/5.24/overloading.pm File/Glob.pm /usr/lib/x86_64-linux-gnu/perl/5.24/File/Glob.pm warnings.pm /usr/share/perl/5.24/warnings.pm Data/Dump.pm /usr/local/share/perl/5.24.1/Data/Dump.pm strict.pm /usr/share/perl/5.24/strict.pm /etc/perl/sitecustomize.pl /etc/perl/sitecustomize.pl XSLoader.pm /usr/local/lib/x86_64-linux-gnu/perl/5.24.1/XSLoader.pm subs.pm /usr/share/perl/5.24/subs.pm [download] Confusing!	[reply] [d/l] [select]
Re^5: 'do' command is dead? Surely not? by Corion (Patriarch) on May 19, 2017 at 14:53 UTC
You don't show us the output of the file existence tests. Maybe the filename has whitespace at its end. If `-f 'whatever.pl'` fails, then for sure, Perl cannot see that file, for whatever reason. Also, the interesting variable is `@INC`, not `%INC`. You can also check if `do './whatever.pl'` works for you. That would also work around the problem of `.` not being in `@INC`. You can also check if `do '/home/Andy/Desktop/whatever.pl'` works for you. That would also work around the problem of `.` not being in `@INC`.	[reply] [d/l] [select]
Re^6: 'do' command is dead? Surely not? by ACI (Acolyte) on May 19, 2017 at 15:08 UTC
Re^7: 'do' command is dead? Surely not? by Corion (Patriarch) on May 19, 2017 at 17:13 UTC
Re^6: 'do' command is dead? Surely not? by ACI (Acolyte) on May 19, 2017 at 15:03 UTC

In Section Seekers of Perl Wisdom