On Mon, Oct 19, 2015 at 07:48:06PM +0530, Prashant Thorat wrote: > Hi All,
Hello,
> I have a file with multiple lines ,I want to assign all content to variable
> & then want to work on it.
> Like want to match pattern /window/ from it.
> how can it is possible ?
> for example -
>
> open ( F1 ,"file.txt") || die "$!";
You should always use strict and use warnings. They will catch a
lot of gotchas that Perl will normally silently ignore.
use strict;
use warnings;
You should prefer the 3-argument open() as a best practice
because it's safer. Also, you should prefer lexical file handles.
Note that there's no need to quote a variable in Perl (Perl is
not a shell language; variable quoting is not necessary). die $!
would suffice. That said, you should probably add some context to
that error so that you know what failed.
For example:
open my $fh, '<', 'file.txt' or die "open: $!";
> $a=<F1>;
You should avoid using $a or $b as variable names because they
have special meaning (i.e., see perldoc -f sort).
See `perldoc perlvar' for $/, the input record separator (AKA
$INPUT_RECORD_SEPARATOR with use English). If set to undef then
you can slurp in the whole file with one read.
my $contents = do {
local $/ = undef;
<$fh>;
};
> if (/window/i){print
> "it is present\n";
> }
It's best to avoid using the default variable, $_, because it can
very easily be overwritten from a distance. You originally
planned to put the contents into $a, but as noted above that's a
bad practice. Instead, I read into $contents.
We can match the contents of the file by binding the regex to the
contents:
if ($contents =~ /window/i) {
print "Contents of file.txt matched window.\n";
}
Even though a lexical file handle will automatically be closed
when it goes out of scope it's still a good practice to manually
close it and check for errors.
close $fh or warn "close: $!";
Regards,
--
Brandon McCaig <bamcc...@gmail.com> <bamb...@castopulence.org>
Castopulence Software <https://www.castopulence.org/>
Blog <http://www.bambams.ca/>
perl -E '$_=q{V zrna gur orfg jvgu jung V fnl. }.
q{Vg qbrfa'\''g nyjnlf fbhaq gung jnl.};
tr/A-Ma-mN-Zn-z/N-Zn-zA-Ma-m/;say'
signature.asc
Description: Digital signature
