cmd.exe piping stress

[tomazos]

Under Windows the result of:

C:/> perl a.pl | perl b.pl

differs from

C:/> perl a.pl > f
C:/> perl b.pl < f

The specific example is:

D:\tmp3>perl units.pl COM1 < dmp4.tests | perl unit2summary.pl
: test selftest randunit
: test selftest ok    # includes all except errors and warnings
: test selftest       # includes all except errors
: test selftest all  # includes also errors and warnings
: mc creation
: mc attr
: mc resdata
: mc container
: mc clone

 1 (11.1111111111111%)   TENTATIVE

D:\tmp3>perl units.pl COM1 < dmp4.tests > dmp4.results

D:\tmp3>perl unit2summary.pl < dmp4.results
PASSED: test selftest randunit
PASSED: test selftest ok    # includes all except errors and warnings
TENTATIVE: test selftest       # includes all except errors
FAILED: test selftest all  # includes also errors and warnings
PASSED: mc creation
FAILED: mc attr
PASSED: mc resdata
PASSED: mc container
PASSED: mc clone

TESTS: 9   PASSED 6 (66%)   TENTATIVE 1 (11%)   FAILED 2 (22%)

D:\tmp3>

I can't explain it. The only difference I see is when I print out multiple local my variables in one print, the characters get corrupted somehow.

Has anyone seen something like this before?

Any ideas about how to proceed with debugging, I'm stumped.

Could it have something to do with cygwin perl? I have both cygwin perl and activestate installed on my machine.

-Andrew.

[BrowserUk]

Any ideas about how to proceed with debugging,

To see what is being received from the pipe, use a one-liner to receive and redirect it:

perl units.pl COM1 < dmp4.tests > dmp4.results
perl units.pl COM1 < dmp4.tests | perl -pe1 > dmp4.piped

diff dmp4.results dmp4.piped

Then you can compare the two.

What are those COM1 references doing?

The comments mention warnings and errors. You are only piping/redirecting STDOUT not STDERR? Not that it should make any difference in what gets redirected or piped as STDERR would get displayed on the console in both cases--unless you are redirecting stuff internally to the program? To the serial port for example?

[tomazos]

Th dmp4.results and the dmp4.piped are identical.

When I then go and run:

C:/> perl unit2summary.pl < dmp4.piped

It works.

When however I run it with "perl units.pl COM1 | perl unit2summary.pl" it doesn't work.

The COM1 identifies the com port. It is part of a basic unit testing framework for a consumer electronics device.

The code for unit2summary.pl follows:

#!perl

use strict;
use warnings;

my %results = ();
my $total;
my $command = '';
my $result = '';

while (<STDIN>) {
    chomp;
    next if /^\s*$/;

    if (/^COMMAND:\s+(.*)$/) {
        $command = $1;
    }

    if (/^RESULT:\s+(.*)$/) {
        $result = $1;
        print "$result: $command \n";
        $results{$result}++;
        $total++;
    }
    
}

print "\n";

print "TESTS: $total   ";
foreach (keys %results) {
    print "$_: " . $results{$_} . " (" . abs($results{$_} * 100 / $tot
+al) . "%)   ";
}
print "\n";

A sample of the dmp4.piped follows:

COMMAND: mc creation

    TIMEOUT: 3
    Creating various ContentData objects
    SUCCESS: Up-Casting HMediaAudioCD to HMediaCD
    SUCCESS: Up-Casting HMediaImageCD to HMediaCD
    SUCCESS: Up-Casting HMediaVideoCD to HMediaCD
    Working with const ContentData objects
    SUCCESS: Creation of new const-pointer HMediaAudioCD initialized w
+ith non-const handle
    SUCCESS: Up-casting constHMediaAudioCD to constHMediaCD
    SUCCESS: Const-Casting from constHMediaAudioCD to HMediaAudioCD
    SUCCESS: Down-casting from constHMediaCD to constHMediaAudioCD
    SUCCESS: Making Const from cpHACDconst to ccpCD not successful
    RETURN: 

RESULT: PASSED

COMMAND: mc attr

    TIMEOUT: 3
    Creating HMediaAudioCD and add Title Attribute
    SUCCESS: HMediaAudioCD created
    SUCCESS: Checking for attribute "title" 
    ERROR: Checking attribute value: This is my lif
    Changing value of Title attribute by re-adding with different valu
+e
    SUCCESS: Checking for attribute "title" (2nd time)
    SUCCESS: Checking if attribute value was updated
    SUCCESS: Checking No. of attributes: 1
    SUCCESS: Re-Checking No. of attributes: 1
    SUCCESS: Removing attribute
    ERROR: Checking if attribute was really removed
    Adding more attributes
    SUCCESS: Attribute 0 has value A
    SUCCESS: Attribute 1 has value B
    SUCCESS: Attribute 2 has value C
    SUCCESS: Attribute 3 has value D
    SUCCESS: Attribute 4 has value E
    SUCCESS: Removing attribute at index 1 in list
    SUCCESS: Trying to remove non-existing attribute at index 5
    ERROR: Removing all 4 Attributes: 4 elements left
    Checking setAttributeValue methods
    SUCCESS: Checking if setting value by name on non existing attribu
+te prohibited
    SUCCESS: Checking if setting value by index on non existing attrib
+ute prohibited
    SUCCESS: Setting value to new attribute
    SUCCESS: Re-setting value of existing attribute at index 0
    Testing const char* - interface
    Adding attribute using const char* interface 
    SUCCESS: Getting value of just added attribute
    SUCCESS: Checking if value of attribute is correct: somewhere over
+ the rainbow
    SUCCESS: Re-setting value of just added attribute using const char
+* interface
    SUCCESS: Getting value of just changed attribute
    SUCCESS: Checking if value of attribute is correct: somewhere over
+ the rainbow
    RETURN: 

RESULT: FAILED

Any help appreciated.

-Andrew.

[BrowserUk]

C:/> perl unit2summary.pl < dmp4.piped

Can I take it from the prompt shown in your command line that you are using some other shell than cmd.exe?

If so, try your commands with cmd.exe. I can't see any difference in the behaviour here:

C:\test>perl -pe1 junk.dat | perl unit2summary.pl
PASSED: mc creation
FAILED: mc attr

TESTS: 2   PASSED: 1 (50%)  FAILED: 1 (50%)

C:\test>perl unit2summary.pl <junk.dat
PASSED: mc creation
FAILED: mc attr

TESTS: 2   PASSED: 1 (50%)  FAILED: 1 (50%)

[ikegami]

I don't know, but I mgiht be able to find out if I had some code to try...