Re: Opening not-existing command

Using SVN::Notify, here's a very simple precheck and snippet:

#!/usr/bin/perl

use strict;
use warnings;
use SVN::Notify;

my $command = 'xmllint --version';

open(my $CMD, "$command |") or die $!;

my $exe = SVN::Notify->find_exe($command);
while (<$CMD>) {
    print $_;
}
close $CMD;
[download]

Update: Try this:

#!/usr/bin/perl

use strict;
use warnings;
use SVN::Notify;

my $command = 'dir';

my $exe = SVN::Notify->find_exe($command);
system($exe);
[download]

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

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Re^2: Opening not-existing command - Error Handling by Dirk80 (Pilgrim) on Aug 16, 2011 at 11:50 UTC
Thank you. Sounds good. I tried it. But my problem is now that I always get the message "Cannot locate command" for a existing command and for a not-existing command.	[reply]
Re^3: Opening not-existing command - Error Handling by Tanktalus (Canon) on Aug 16, 2011 at 13:20 UTC
Remember that "dir" is not an executable. It's a shell built-in. So try "cmd /c dir" as your command (and thus your executable is "cmd"). Though, really, dir is a bad example because it's so trivial to do inside perl. Other built-ins may be more difficult/impossible to emulate in perl, so the question is still more or less valid as a general question, just not so much for this particular example.	[reply]
Re^2: Opening not-existing command - Error Handling by Dirk80 (Pilgrim) on Aug 17, 2011 at 12:50 UTC
Thanks. Now it works fine after your update. Here a sample code snippet: `#!/usr/bin/perl use strict; use warnings; use SVN::Notify; my $command = 'perl'; my $exe = SVN::Notify->find_exe($command); if( defined $exe ) { print "Command \"$command\" exists!"; } else { print "Command \"$command\" does NOT exist!"; }` [download] Only problem is that it is not able to handle parameters. If I use the command "perl --version" then I receive the answer that this command does not exist. If I use only "perl" then I get the answer that it exists. Fazit: Thank you a lot. This is a very good method to find out whether a command exists or not. But it is necessary to cut away the parameters of the command before giving it to the `SVN::Notify->find_exe` function.	[reply] [d/l] [select]