using grep and diff

[Chris]

use Shell("grep", "diff");
my $item=diff("file1 file2","");
my $other=grep($item,""^[0-9]"");

How can I get this to work beacuse the grep need the "" around the ^[0-9] or
is it possible to put the diff and grep into a shell script and then have
perl run the script? if so how would it be done.

 

[A. Sinan Unur]

use Shell("grep", "diff");

Are you still insisting on this?

perldoc Shell

perldoc -f system

my $item=diff("file1 file2","");
my $other=grep($item,""^[0-9]"");

How can I get this to work beacuse the grep need the "" around the
^[0-9] or is it possible to put the diff and grep into a shell script
and then have perl run the script? if so how would it be done.

perldoc perlop

See "Quote and Quote-like Operators".

Sinan

 

[Jürgen Exner]

use Shell("grep", "diff");
my $item=diff("file1 file2","");
my $other=grep($item,""^[0-9]"");

How can I get this to work beacuse the grep need the "" around the
^[0-9]

Is there anything wrong with a simple

my @foo = `diff file1 file2`;

and then using Perl's own grep() instead of forking out an external process?

or is it possible to put the diff and grep into a shell script
and then have perl run the script? if so how would it be done.

Just the same way you would run any other external program from Perl: by
using system(), backticks, or open() with a pipe.

jue

 

[Christopher Nehren]

use Shell("grep", "diff");
my $item=diff("file1 file2","");
my $other=grep($item,""^[0-9]"");

Wow ... shelling out to do text processing in Perl! Seriously. Get some
modules and learn about Perl's regex engine (which is infinitely better
than anything your grep can ever provide, by the way[1]) and the
Algorithm:iff module.

[1]: Unless it was written in Perl, of course ...
http://search.cpan.org/src/CWEST/ppt-0.14/bin/grep

Best Regards,
Christopher Nehren