Using pathnames in Windows is disturbingly annoying. While on its face, your code appears to have no issues, there could be any number of problems. For example, if Perl is installed with restricted priviledges, it may not have rights to invoke your shell (cmd.exe on Windows 2k/XP). However, if I were a betting man, I'd bet that something odd about your path spec is tripping things up.

The solution is one of two things. First, you could use File::Spec to build your path, thus basically eliminating the potential for path-related problems. That's usually a good idea even if you aren't having problems.

Or, because you say I need to use the batch file because the program it's running assumes /program files/agent is the working dir, you could simply use chdir. Like so:

my $real_prog = 'agent.exe';
my $path = File::Spec->canonpath('c:\program files\agent');
chdir ($path);
system ($real_prog) if (-f $real_prog);
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Are you sure that your file is really there?

Writing Windows path names correctly can be tricky sometimes. Try this one:

#!/usr/bin/perl -w
use strict;
my $prog = "c:\\program files\\agent\\agent.bat";

if (-f $prog)   # does it exist?
{
    system("cmd.exe", "/C", $prog);
}
else  # if not, let's see its name after escaping "\"s
{
    warn "batch file ($prog) not found!\n";
}
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I get the same result: Can't spawn "cmd.exe": No such file or directory. This makes me wonder if perl has the right path for cmd.exe. But then if I put a .bat file in the same directory as my perl script, it runs just fine! Very strange.

And as for the other suggestion about running as admin, my account is not literally admin but it is a member of the admin group and I have full admin privileges.

Steve

I'd recommend adding a chdir to the script. BAT files can be annoying when you have to call them from Perl scripts. Also, it may not necessarily be the BAT file in and of itself, but if its calling an executable thats assuming a certain directory, then things get trickier. The whole process is annoying and requires patience to get it working correctly.

 
#!/usr/bin/perl -w
use strict;
use File::Spec;
my $prog = File::Spec->catfile('program files', 'agent', 'agent.bat');
system($prog);
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Also perl generally doesn't like paths that have spaces so you might want to try quoting the path and then running it again.

-Hokie
all code is untested

#!/usr/bin/perl -w
use strict;
my $prog = "\"c:\\program files\\agent\\agent.bat\"";
system($prog);
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Hi holli ,

I don't think this will work, in fact i just tested and it doesn't work !
Protecting the command itself with quotes doesn't protects from the space, at least in my shell.

zlr

I've found protecting it with single quotes instead of double quotes often works. Something like:

$file=File::Spec->catfile('c:','path',with spaces',to','file');
$file="\'$file\'";
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Try putting quotes inside the string, around the full path.

my $prog = "c:\\program files\\agent\\agent.bat";
system(qq("$prog"));
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The "fix everything" solution is, of course, to use a path without spaces.

I'm not to sure that's the real problem, If it were they would get an error along the lines of 'c:\program' is not recognized as an internal or external command, operable program or batch file.

For that matter, no matter how I've tried to mangle the path to the bat, I can't get any errors about cmd.exe, I've even emptied everything out of the Path, and all that happened then is, ... well nothing, the script runs but the bat either doesn't run or has no output, but no error. I tried to see if I could generate the error by renaming cmd.exe, but I just got a new one right away.

update: ah here we go, forgot to turn warnings on when testing:
With Path emptied of everything but perl, I get the same error, and just to see if I could match, I ran the script from the same directory and gave it just the name of the .bat, and it ran just fine. So i would have to agree with some of the previous posters in that it's a problem with the the Path environment variable, it apparently doesn't contain the path to cmd.exe. Though I'm not entirely certain why everything runs fine when it's passed just the batch file's name

update: minor reformatting

Just Another Perl Alchemist

Yeah, I'm not convinced that $prog has anything to do with it. When tested under Win2000 Pro running Activestate's version of Perl 5.8.4, I could not duplicate the issue. Of course, since I have no idea what's in the batch file, I can't say for sure what the problem is.

But where $prog in test.pl reads:


my $prog = "c:\\program files\\bwb.bat"; # personal batch file for sundry tasks

test.pl yields no errors.

Where $prog in test.pl reads:


my $prog = "c:\\progra~1\\bwb.bat";

test.pl yields no errors

/renz.

(EDIT: Also, I am working with local admin privs.)

I think the problem comes from the space in "Program Files".
The comand you launch with "system" doesnt work in my cmd shell ! And the error shows it stops at the space.

There's a lot of workarounds, there maybe is one in the windows shell itself but i cant find it.
Along with the other solutions in this thread i would also consider Win32::Process .

ZlR

I haven't worked on PC scripts since NT 4.0, but at that time long file names didn't work at all, you had to use the old style DOS type ones, 8.3 and tilde characters. If this is still the case, the following path may work:

CleanPath will automatically strip out any invalid directories from your path (both for the current command shell and in the global configuration in the Registry -- though most other things won't notice these changes unless you log out or otherwise poke them to).

It doesn't fix directories that still exist but that shouldn't be in %PATH%, though.

- tye        

I had this issue with some perl scripts I had inherited at work (activeperl 5.6 on server 2003). It turned out to be the way the script was being called from the command line (scheduled .cmd file). e.g. c:\scripts>script.pl (resulted in the can't spawn message) however specifying perl before calling the script which is best practice anyway allowed it to work fine: c:\scripts>PERL script.pl (allows the command line call from within the perl script to work fine).

Fixed on Windows 7, 64 bits command prompt adding the cmd.exe path in PATH like this: set PATH=%PATH%;C:\Windows\SysWOW64

I had the same problem on WinXP with Activestate 5.8.8. I tried changing the env path (quoting all the entries with spaces), changing the path temporarily in the script by setting $ENV{PATH} and in a desperate measure putting cmd.exe in the same directory as my perl script. nothing worked. Then, I tried using system like this:

my $ret = system "C:\\WINDOWS\\System32\\cmd.exe /C $syscall";

where $syscall is a string you set with the program you want to call and all its arguments. Worked perfectly for me, after way too long scratching my head... Anyway, I hope it helps someone else.