GentleMonks -

I have a perl program (don't you hate it when people call them 'scripts') that processes thousands of xml files that have been individually tgz compressed.

I have been plagued by apparently random failures during "extract" in Archive::Extract. After hours debugging, I believe that the root cause is apparently inside Cwd::cwd, which is used by Archive::Extract. The cwd() function calls '/bin/pwd' via backticks - this works fine most of the time, but I finally caught a case where it returns undef.

At the time it returns undef, I examined $!, which contained - you guessed it - 'Cannot allocate memory'.

The underlying tgz/xml file DOES process successfully when passed through the program individually, or in a small group of files.

Please advise how to diagnose further, or other recommend steps. UPDATE : Here is the failure I get: 

Key 'archive' (filename.gz) is of invalid type for 'Archive::Extract::
+new' provided by main::parse_XML at PerfDBparse.pl line 447
 at /usr/share/perl/5.10/Params/Check.pm line 345
        Params::Check::check('HASH(0x2a3e660)', 'HASH(0x2a3e5a0)') cal
+led at /usr/local/share/perl/5.10.0/Archive/Extract.pm line 227
        Archive::Extract::new('Archive::Extract', 'archive', 'FileName
+.gz') called at PerfDBparse.pl line 447
        main::parse_XML('filename', 'allXML', 288600) called at PerfDB
+parse.pl line 131
       ...(Truncated, and file names changed to protect the innocent).
+..

[download]
OS: Linux ManchineName 2.6.28-19-server #64-Ubuntu SMP Wed Aug 18 22:43:50 UTC 2010 x86_64 GNU/Linux

Memory info at time of failure: 

dmin [ ~ ]$ free -m
             total       used       free     shared    buffers     cac
+hed
Mem:          1987       1873        114          0        125        
+275
-/+ buffers/cache:       1471        515
Swap:          475         33        442

[download]
This is the first time I'm dealing with an apparent memory leak. Any known issues ? BTW, I use XML::Bare for XML parsing.

     Syntactic sugar causes cancer of the semicolon.        --Alan Perlis

In reply to backticks and 'Cannot allocate memory' by NetWallah

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