Re^2: Opening not-existing command

I tried the following:

#!/usr/bin/perl

use strict;
use warnings;

open(my $CMD, "dira |") || die "another text";
# ...
close($CMD);
[download]

But the program still produces the same error message:

Der Befehl "dira" ist entweder falsch geschrieben oder
konnte nicht gefunden werden.
[download]

Comment on Re^2: Opening not-existing command - Error Handling Select or Download Code

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Re^3: Opening not-existing command - Error Handling by AR (Friar) on Aug 16, 2011 at 15:29 UTC
Not for me: `#!/usr/bin/perl use strict; use warnings; open(my $CMD, "dira \|") \|\| die "something else\n"; while( <$CMD> ) { print "$_"; } close($CMD);` [download] Output: `Can't exec "dira": No such file or directory at ./test.pl line 6. something else` [download]	[reply] [d/l] [select]
Re^3: Opening not-existing command - Error Handling by Anonymous Monk on Aug 17, 2011 at 04:13 UTC
This form of `open` starts a child process. The return result is the child process ID. Thus, your `open(...) \|\| die ...` will show the error if the child can't be created. You need to check `$?` to check for errors from the child. See this for an example of checking for errors in this situation.	[reply] [d/l] [select]
Re^4: Opening not-existing command - Error Handling by Dirk80 (Pilgrim) on Aug 17, 2011 at 12:37 UTC
Thanks. You are right. Examining `$?` helps to know if the child process executed correctly or not. Here my sample code: `eval { open my $pipe, "perl --version \|"; my @res = <$pipe>; close $pipe; }; print "Exit Status: " . ($?>>8);` [download] If I use the not existing command "perl2 --version" then I get the following error message and the exit status 1. `Der Befehl "perl2" ist entweder falsch geschrieben oder konnte nicht gefunden werden. Exit Status: 1` [download] If I use an existing command like "perl --version" then I get the exit status 0 and no error message: `Exit Status: 0` [download] Problem of course is that I then know the error not directly after the `open`, but only when the child process exited, that means after the `close`.	[reply] [d/l] [select]