topic Re: script help in Operating System - HP-UX

script help

joe_91 — Thu, 03 Mar 2005 20:13:25 GMT

Could someone just tell me what the cshell script does and answer to the perl script?

#!/usr/bin/csh
set list = `ls`
foreach file ( $list )
set size = `wc -c $file`
if( (-f $file) && ($size[1] < 1000) ) echo $file
end
---------------------------------------------------

What will the following Perl script print out?
----------------------------------------------

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

my @files = ('something.data',
'file.dat',
'data.txt',
'alpha.datdat',
'beta.a.dat');
my @list = ();

foreach my $file (@files) {
next if ( $file !~ m/\.dat$/i );
push(@list, $file);
}

foreach my $item (@list) { print "$item\n"; }
exit;

Please..could anyone help?

Thanks

Joe

Re: script help

Stephen Keane — Fri, 04 Mar 2005 04:37:59 GMT

The cshell script will echo the names of all files (not directories) in the current directory that have less than 1000 characters in them. It does not do a recursive list.

Re: script help

Peter Godron — Fri, 04 Mar 2005 05:19:04 GMT

Joe,
perl script:
create an array (@files) and populate with data
create an empty array(@list)

go through the entries in the files array
if the entry ends in a ".dat" append to list array

print each of the entries in the list array

Regards

Re: script help

H.Merijn Brand (procura — Fri, 04 Mar 2005 06:23:51 GMT

And the inefficient perl script can be written much shorter:

--8<---
#!/usr/bin/perl -lw
use strict;

my @files = qw(something.data
file.dat data.txt alpha.datdat beta.a.dat);
my @list = grep /\.dat$/i => @files;
print for @list;
-->---

the list @files is a list of predefined file names. @list is then stuffed with the names that match the file names that end on .dat (case insensitive), and that list is then printed to the standard output (your screen)

and reduce that to

--8<---
#!/usr/bin/perl -lw
use strict;

print for grep /\.dat$/i => qw(something.data
file.dat data.txt alpha.datdat beta.a.dat);
-->---

Which was probably an elaborate way to check what would happen on

# perl -lwe'print for grep m/\.dat$/i => <*dat*>'

Enjoy, Have FUN! H.Merijn

Re: script help

Peter Godron — Mon, 07 Mar 2005 08:02:59 GMT

Joe,
is this still a problem?
If not can you please identify the solution and close the thread, otherwise please update.
Thanks