Re: Re: substitution in $0

I agree, testing your code you need to either do as rollyguy has suggested, or it does work doing:

open (PROG, "+>>$0");
[download]

In running your code withthe + in it, I have found your regexp does not work as well.
Here is my version, and followed by the output:

#!/usr/bin/perl

use strict;
use warnings;

my $new_value = 10;
my $data=45;

open (PROG, "+>>$0");
seek (PROG, 0, 0);     #not working 
while (<PROG>)
{
  s/^(my .data\s*=\s*)\d+(\s*;)/$1.$new_value.$2/e;
  print;
}
close (PROG);
[download]

Output:

#!/usr/bin/perl

use strict;
use warnings;

my $new_value = 10;
my $data=10;

open (PROG, "+>>$0");
seek (PROG, 0, 0);     #not working 
while (<PROG>)
{
  s/^(my .data\s*=\s*)\d+(\s*;)/$1.$new_value.$2/e;
  print;
}
close (PROG);
[download]

Note: I'm not writing to the file itself, now that I'm thinking about it you probably want to write a temp file, then copy it over....

Hope this helps!

Comment on Re: Re: substitution in $0 Select or Download Code

Replies are listed 'Best First'.
Re: Re: Re: substitution in $0 by Discipulus (Canon) on Oct 03, 2002 at 12:00 UTC
Thanks to all you monks for the precious suggestions you gave to me! I know my code is still terrible!! #!perl use strict; use warnings; &changemyself(); sub changemyself{ my $new_value = 10; my $data=6666666666666; #next time this value will be 10 open (COPIA, ">copia"); open (PROG, "+>>$0"); seek (PROG, 0, 0); #I don't know why but it's NECESSARY! while (<PROG>) { s/^( my .data\s=\s)\d+(\s;)/$1.$new_value.$2/e; print COPIA; } close (PROG); # close (COPIA); # # the terrible imitation # of the open (COPIA, "<copia"); # three cards game open (PROG, ">$0"); # while (<COPIA>){print PROG}# close (PROG); # close (COPIA); # unlink ("copia"); # } [download] Special thank to Helter! greetings from roma, lor PS I never noticed the +>> operator!!! l*	[reply] [d/l]
Re: Re: Re: Re: substitution in $0 by fglock (Vicar) on Oct 03, 2002 at 12:23 UTC
`open (PROG, "+>>$0"); seek (PROG, 0, 0); #I don't know why but it's NECESSARY!` [download] Because `>>` moves the file position to end-of-file.	[reply] [d/l] [select]


Don't ask to ask, just ask
	PerlMonks