Re: Can you teach a new dog an old trick?

[bikeNomad]

It's such a common idiom that the -p and -i command-line flags were invented to deal with it:

#!/usr/bin/perl -wpi
s/string1/string2/g;

And then you'd run it as: myScript *.htm

update: note that the contents of a script run with -p or -n are inside a loop. If you want to initialize anything before the loop, use a BEGIN or INIT block.

[PetaMem]

This is not good...

I tried to extend it to:

#!/usr/bin/perl -wpi
my $src = shift;
my $dst = shift;
s/$src/$dst/g;

and it throws many many messages on me:

Use of uninitialized value in substitution (s///) at /home/rj/bin/repl
+ace line 4, <> line 38.
Use of uninitialized value in regexp compilation at /home/rj/bin/repla
+ce line 4, <> line 39.
Use of uninitialized value in substitution (s///) at /home/rj/bin/repl
+ace line 4, <> line 39.
Use of uninitialized value in regexp compilation at /home/rj/bin/repla
+ce line 4,

(called "replace hallo hello tmp.txt")
Then I looked at man perl what this switch -p does
ok it was not there, so I looked at man perlrun and
then I found the error (it tries to get $src and $dst in every
loop. Well, I´m using my old replace script now again...


#!/usr/bin/perl
my $src = shift;
my $dst = shift;
 
print "Replace >$src< with >$dst<.\n";
 
$dst =~ s/\\n/\n/g;
$dst =~ s/\\t/\t/g;
 
foreach $file (@ARGV) {
    my $file2 = "/tmp/$file.".$$;
 
    print "replacing in File: $file...\n";
    print "$file2\n";
    open HANDLE, $file or die "$file: $!";
    while(<HANDLE>) {
        $zeile .= $_;                    # Zeile von Datei einlesen
    }
    close HANDLE;
 
    $zeile =~ s/$src/$dst/gs;
 
    open HANDLE, ">$file2";
    print HANDLE $zeile;
    close HANDLE;
    $zeile = '';
    system("mv $file2 $file");
}

Its ugly and unelegant and made 1996, but it works. :-)

Ciao

[mugwumpjism]

You need to use a BEGIN block, like so:

#!/usr/bin/perl -wpi
BEGIN { ($src,$dst)=(@ARGV); }
s/$src/$dst/g;