How do i make a "system call to tar files(along with exclude tag)" to work in Perl

Question

This is the system call, i am making right now in perl to tar the files

system("${tarexe} -pcvf $tarname $includepath") which works fine.

$tarexe -> location of my tar.exe file
$tarname -> myMock.tar
$includepath -> ./input/myMockPacketName ./input/myPacket/my2/*.wav ./input/myPacket/my3 ./input/myPacket/in.html 

Now i want to exclude some files using exclude tag, which doesnot exclude the files

system("${tarexe} -pcvf $tarname $includepath --exclude $excludepath")

$excludepath -> ./input/myMockPacketName/my3

The same stament

${tarexe} -pcvf $tarname $includepath --exclude $excludepath  

doesnot work when i run it in the command line.

Answer 1

I haven't a clue to why your --exclude isn't working. But I'll give you my favourite perl advice when I see a system in use.

Don't

Of course sometimes they are necessary but check first if there is a CPAN module to do the job instead. In this case I suggest Archive::TarGzip normally I would use Archive::Tar but I could not find --exclude functionality (I only had a quick look so it may be there)

Answer 2

@superstar -

To asnwer your specific question, --exclude should probably be "./input/myMockPacketName/my3/*" instead of "./input/myMockPacketName/my3" from what I recall of GNU tar. Also, included file names are supposed to go after --exclude stuff; which should be quoted properly

BUT

Why are the requirements telling you HOW to do stuff as opposed to WHAT to do?

Unless it's homework (in which case please be upfront about it)

... or those are requirements from some company's generic architecture team (in which case they should be politely educated that industry standard best practices are to use Perl's native libraries over system calls whenever possible unless there's a clear reason to do otherwise) ...

in every other but those 2 cases you should decide on what method to use for implementation.

Answer 3

Not a direct answer to the question but a hint that might help you pin down problems like this in the future:

Rather than write

system("${tarexe} -pcvf $tarname $includepath --exclude $excludepath")

do something like

my $command = "${tarexe} -pcvf $tarname $includepath --exclude $excludepath"  ;

print "About to run $command\n" ;
system $command ;

You can then cut and paste the output getnerated into a new terminal window. Or you may spot that the command generated isnt what you thought it was.

Disclaimer - I agree with most people that have ansewred this question that using Perl Tar modules would be better, but accept there may be reasons for doing it this way

Answer 4

I appear to be having the same problem, but in a CGI application that uses /usr/bin/zip.

The zip commandstring below works as expected from the commandline on both Solaris and Mac OS X: the paths are excluded and I get a zip file containing only the files matching *.$fileext. But when I run the same command via Perl system(), the zip file contains empty directories for the full path from host root down to htdocs, with the files in the last directory.

Both the commandline and system() cases send the expected STDOUT to the file $joblog, and nothing shows up in the file $joberrors.

This excludes directories as advertised in man zip:

> /usr/bin/zip -D $zipfile $somepath/*.$fileext 1>$joblog 2>$joberrors

This does not:

$zipcommand = "/usr/bin/zip -D $zipfile $somepath/*.$fileext 1>$joblog 2>$joberrors"; system("$zipcommand");

Ideas?