in reply to Can't spawn "cmd.exe":

Thinking that this might be some weird sort of 32/64 bit issue, ...

I can't reproduce your errors using AS1004 Perl 64-bit running under Vista 64-bit. 

#! /usr/bin/perl -slw
use strict;

print "About to try fail 1";
my $testfile = "test.exe";
my $test = "/C ${testfile} localhost root pwd";
system ("cmd", $test);

print "About to try fail 2";
$test = "${testfile} localhost root pwd";
system ($test);

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In the following test.exe just displays its args: 

c:\test\test\test>test.pl
About to try fail 1
0 : test.exe
1 : localhost
2 : root
3 : pwd

About to try fail 2
0 : test.exe
1 : localhost
2 : root
3 : pwd

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In the first case Perl starts cmd.exe, which runs test.exe. In the second, perl runs test.exe directly. No error messages are produced by either.

What version/build of Perl are you using?

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.
"Too many [] have been sedated by an oppressive environment of political correctness and risk aversion."

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Re^2: Can't spawn "cmd.exe":
by emalossi (Novice) on Mar 18, 2009 at 14:33 UTC
    Browser, It's 5.8.8. I think almut is on to something in his reply concerning negative return codes. Can you verify this by returning -1 from your test executable?
[reply]

      Indeed I can: 

      C:\test\test\test>test.pl
About to try fail 1
0 : test.exe
1 : localhost
2 : root
3 : pwd

Can't spawn "cmd": No error at C:\test\test\test\test.pl line 7.
About to try fail 2
0 : test.exe
1 : localhost
2 : root
3 : pwd

Can't spawn "test.exe localhost root pwd": No error at C:\test\test\te
+st\test.pl line 11.

      [download]

      Same result whether the return value is -1 or -100_000.

      The problem is with Perl's handling of Windows return codes. Trying to force fit a 32-bit signed int into an unsigned char doesn't go :)

      As for what constitutes a "valid windows return code"--a signed integer covers it. Long ago, there was a convention that positive return codes were 'informational', negative 'failures', with zero being unadorned success.

      Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
      "Science is about questioning the status quo. Questioning authority".
      In the absence of evidence, opinion is indistinguishable from prejudice.
[reply]
[d/l]

        The problem is with Perl's handling of Windows return codes. Trying to force fit a 32-bit signed int into an unsigned char doesn't go :)

        That's quite wrong.

        For starters, Windows error codes are unsigned.
        ExitProcess
        GetExitCodeProcess

        The problem occurs when coercing the 32-bit unsigned value into 31-bits (a 32-bit signed value where negative has a special meaning). 

        DWORD status;
...
GetExitCodeProcess(ProcessInformation.hProcess, &status);
ret = (int)status;

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        Forcing the value into 8 bits doesn't even happen when you see that warning. 

        if (status < 0) {
    if (ckWARN(WARN_EXEC))
        Perl_warner(aTHX_ packWARN(WARN_EXEC), "Can't spawn \"%s\": %s
+", argv[0], strerror(errno));
        status = 255 * 256;
    }
    else
        status *= 256;            <---- coercion into 8 bits
    PL_statusvalue = status;
}

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