pattern matching

[rohitkec]

I have tried the following code:

#! /usr/bin/perl
use Switch;
$i=0;
open(FILE,"$ARGV[0]") || die "cannot open file";
@lines = <FILE>;
close(FILE);
open(wfile,">$ARGV[1]");
while ($lines[$i]) {
    $line = $lines[$i];
    if ( ($line =~ m/(^\w+)(\s+)(\()(\))/) 
        || ($line =~ m/(^\w+)(\s+)(\()(\s+)(\))/)
        || ($line =~ m/(^\s+)(\w+)(\s+)(\()(\s+)(\))/)
        || ($line =~ m/(^\s+)(\w+)(\s+)(\()(\))/)
        || ($line =~ m/(^\s+)(\w+)(\()(\s+)(\))/)
        || ($line =~ m/(^\s+)(\w+)(\()(\))/)
        || ($line =~ m/(^\w+)(\()(\))/)
        || ($line =~ m/(^\w+)(\()(\s+)(\))/)
    ) {
        $b = $1; $a = $2;
        if ($1 =~ m/(\s+)/) {
            $b = $a;
        }
        $x = 1;
        print wfile $line;
        if ($line =~ m/\{/) {
            $z = 1;
            print wfile "echo \"calling func. $b\"\n";
        }
        $i++;
        $line = $lines[$i];
        if ($line =~ m/(^\{)/) {
            $z = 1;
            print wfile $line;
            print wfile "echo  \"calling func. $b\"\n";
        }
        while ($z ==1 ) {
            $d = $line;
            $i++;
            $line = $lines[$i];
            switch($line) {
                case m/\{/ {
                    $x++;
                    print wfile $line
                }
                case m/\}/ {
                    $x--;
                    if ($x!=0) {
                        print wfile $line
                    }
                }
                else {
                    print wfile $line
                }
            }
            if ($x == 0) {
                $z=0;
                print wfile "echo \"return from $b\"\n";
                print wfile $line
            }
        }
 
    } else {
        print wfile $line;
    }
    $i++;
}
close(wfile);
 

this code is for identifying a function in shell script & inserting echo statements when it is been called and returned.....
can u suggest someting to make it more efficient..