Search and replace

[kulua]

I want to replace below string

input bist_g6bb_prn_clk_bistctlr;

to

output bist_g6bb_prn_clk_bistctlr;

and then change the output bist_g6bb_prn_clk_bistctlr; string to

assign vif.bist_g6bb_prn_clk_bistctlr = bist_g6bb_prn_clk_bistctlr;

use strict;
use warnings;
use autodie;

my $data = <<'EOD';

input  bist_g6bb_prn_clk_m;
EOD

open my $fh, '<', \$data;

while (my $line = <$fh>) {
    $line =~ s/input .*clk/output .*clk/g;
    print $line;
    }

close $fh;

I am new to perl, Can you point me my mistake ?

[hippo]

    $line =~ s/input .*clk/output .*clk/g;

The first part of s/// is a regular expression but the second part is a string. It is essentially s/REGEX/STRING/. Since (in the first part of your task, which is the only part your code attempts to address) there are no complications, you can ignore the rest of the pattern and just do this:

    $line =~ s/input/output/;

That should get you farther along. For the general case you would need to use capture groups.

[kulua]

Hi Hippo ,

I want to change the string to output when the string clk matches not the input to output

Can you provide me good tutorial for reg expression ?

[hippo]

You could try Regular Expressions Tutorial, the Basics (for BEGINNERS) which is listed on our Tutorials page under the Pattern Matching, Regular Expressions, and Parsing section. There's also the official tutorial at perlretut. Enjoy.

[tybalt89]

$line =~ s/input(?= .*clk)/output/g;

Untested since no test cases were provided.

[1nickt]

Please answer this question: have you read and studied the examples in perlrequick? There is a section entitled exactly "Search and replace".