Have perl increment a number that shows up before a delimiter

**Purl Gurl** · Jul 19 '05, 04:46 AM

Re: Have perl increment a number that shows up before a delimiter

john brown wrote:

[color=blue]
> To be exact something like "/home/song1.mp3". I want to
> introduce this on the command line and have the script increment this
> file 9 times.[/color]
[color=blue]
> /home/song2.mp3, /home/song3.mp3 /home/song4.mp3[/color]

Change my $path variable to:

"/home/song10.mp3"

"/home/song.mp3"

Note results carefully, then give those results thought.

Purl Gurl
--
Corvette Mako Sharks! 56 Chevy Napco 4X4!

http://www.purlgurl.net/~godzilla/

#!perl

$path = "/home/song1.mp3";

$count = substr ($path, rindex ($path, ".") - 1, 1);

for ($count .. 9)
{ substr ($path, rindex ($path, ".") - 1, 1, $count++); print "$path\n"; }

PRINTED RESULTS:
_______________ _

/home/song1.mp3
/home/song2.mp3
/home/song3.mp3
/home/song4.mp3
/home/song5.mp3
/home/song6.mp3
/home/song7.mp3
/home/song8.mp3
/home/song9.mp3

**Jim Gibson** · Jul 19 '05, 04:46 AM

Re: Have perl increment a number that shows up before a delimiter

In article <543320e0.03102 01944.563fbe4d@ posting.google. com>, john
brown <cglobal25@hotm ail.com> wrote:
[color=blue]
> I'm new to perl programming and would like some help if at all
> possible. I'm trying to make a simple script where I can input a
> filename. To be exact something like "/home/song1.mp3". I want to
> introduce this on the command line and have the script increment this
> file 9 times.I.e. /home/song2.mp3, /home/song3.mp3
> /home/song4.mp3, etc. I suppose the period, ".", would be the
> delimiter. I've put down the basics but I'm stumped with the body of
> the program. Any help would be appreciated. I posted the little bit
> I came up with.
>
> #!/usr/bin/perl
>
>
> use strict;
> use warnings;
> print "Input mp3 name ";
> my $mp3;
>
> # Maybe chomp the newline here[/color]

There is no newline if you have entered the filename on the command
line. What you entered is in $ARGV[0] (you should check $#ARGV to see
if you actually entered anything).
[color=blue]
>
> # Find the delimiter and increment the filename[/color]

You might have other periods in the filename, so it is best to look for
the substring '.mp3' in a regular expression.
[color=blue]
>
> # Loop it 9 times[/color]

You want to use a regular expression that matches a number before the
'.mp3', extracts the number and whatever was before it, and increments
the number in a loop. Something like this will work for any number of
digits in the number:

#!/opt/perl/bin/perl
use strict;
use warnings;
if( $ARGV[0] =~ /(\S+)(\d+)\.mp3 $/ ) {
my $base = $1;
my $num = $2;
print $base . $num++ . ".mp3\n" for (1..9) ;
}

See perldoc perlre

**john brown** · Jul 19 '05, 04:46 AM

Re: Have perl increment a number that shows up before a delimiter

Purl Gurl <purlgurl@purlg url.net> wrote in message news:<3F94C52F. E177F03A@purlgu rl.net>...[color=blue]
> john brown wrote:
>
>[color=green]
> > To be exact something like "/home/song1.mp3". I want to
> > introduce this on the command line and have the script increment this
> > file 9 times.[/color]
>[color=green]
> > /home/song2.mp3, /home/song3.mp3 /home/song4.mp3[/color]
>
>
> Change my $path variable to:
>
>
> "/home/song10.mp3"
>
> "/home/song.mp3"
>
>
> Note results carefully, then give those results thought.
>
>
> Purl Gurl
> --
> Corvette Mako Sharks! 56 Chevy Napco 4X4!
> http://www.purlgurl.net/~godzilla/
>
>
> #!perl
>
> $path = "/home/song1.mp3";
>
> $count = substr ($path, rindex ($path, ".") - 1, 1);
>
> for ($count .. 9)
> { substr ($path, rindex ($path, ".") - 1, 1, $count++); print "$path\n"; }
>
>
> PRINTED RESULTS:
> _______________ _
>
> /home/song1.mp3
> /home/song2.mp3
> /home/song3.mp3
> /home/song4.mp3
> /home/song5.mp3
> /home/song6.mp3
> /home/song7.mp3
> /home/song8.mp3
> /home/song9.mp3[/color]

Thanks for the quick reply. Works!

**john brown** · Jul 19 '05, 04:46 AM

Re: Have perl increment a number that shows up before a delimiter

Jim Gibson <jgibson@mail.a rc.nasa.gov> wrote in message news:<211020031 716425322%jgibs on@mail.arc.nas a.gov>...[color=blue]
> In article <543320e0.03102 01944.563fbe4d@ posting.google. com>, john
> brown <cglobal25@hotm ail.com> wrote:
>[color=green]
> > I'm new to perl programming and would like some help if at all
> > possible. I'm trying to make a simple script where I can input a
> > filename. To be exact something like "/home/song1.mp3". I want to
> > introduce this on the command line and have the script increment this
> > file 9 times.I.e. /home/song2.mp3, /home/song3.mp3
> > /home/song4.mp3, etc. I suppose the period, ".", would be the
> > delimiter. I've put down the basics but I'm stumped with the body of
> > the program. Any help would be appreciated. I posted the little bit
> > I came up with.
> >
> > #!/usr/bin/perl
> >
> >
> > use strict;
> > use warnings;
> > print "Input mp3 name ";
> > my $mp3;
> >
> > # Maybe chomp the newline here[/color]
>
> There is no newline if you have entered the filename on the command
> line. What you entered is in $ARGV[0] (you should check $#ARGV to see
> if you actually entered anything).
>[color=green]
> >
> > # Find the delimiter and increment the filename[/color]
>
> You might have other periods in the filename, so it is best to look for
> the substring '.mp3' in a regular expression.
>[color=green]
> >
> > # Loop it 9 times[/color]
>
> You want to use a regular expression that matches a number before the
> '.mp3', extracts the number and whatever was before it, and increments
> the number in a loop. Something like this will work for any number of
> digits in the number:
>
> #!/opt/perl/bin/perl
> use strict;
> use warnings;
> if( $ARGV[0] =~ /(\S+)(\d+)\.mp3 $/ ) {
> my $base = $1;
> my $num = $2;
> print $base . $num++ . ".mp3\n" for (1..9) ;
> }
>
> See perldoc perlre[/color]

The initial code actually works pretty well. I did modify it to look
for ".mp3" instead of just ".". I've also tried to modify it to write
it's output to a file instead of STDOUT with no luck. I've been
placing "printf OUTPUTFILE "$path";" inside the loop but receive
errors. I would like to increment the original name and have it write
to a file. Right now the script of course writes the last result
only, i.e. /home/mysongs/mysong10.mp3". Any ideas?

**Roy Johnson** · Jul 19 '05, 04:46 AM

Re: Have perl increment a number that shows up before a delimiter

This newsgroup is defunct. Use comp.lang.perl. misc instead. Or perl.beginners.

This increments the first string of digits that are followed by a dot.

my $song = '/home/song1.mp3';
for (0..9) {
print "$song\n";
$song =~ s/(\d+)\./(1+$1).'.'/e;
}

Here's a variation on Jim Gibson's, but with more shortcuts:

my $song = '/home/song1.mp3';
my ($num) = ($song =~ /(\d+)\./);
print $` . $num++ . ".$'\n" for 0..9;

**Jim Gibson** · Jul 19 '05, 04:46 AM

Re: Have perl increment a number that shows up before a delimiter

In article <543320e0.03102 20633.d8eb2fb@p osting.google.c om>, john brown
<cglobal25@hotm ail.com> wrote:
[color=blue]
> Jim Gibson <jgibson@mail.a rc.nasa.gov> wrote in message
> news:<211020031 716425322%jgibs on@mail.arc.nas a.gov>...[color=green]
> > In article <543320e0.03102 01944.563fbe4d@ posting.google. com>, john
> > brown <cglobal25@hotm ail.com> wrote:
> >[color=darkred]
> > > I'm new to perl programming and would like some help if at all
> > > possible. I'm trying to make a simple script where I can input a
> > > filename. To be exact something like "/home/song1.mp3". I want to
> > > introduce this on the command line and have the script increment this
> > > file 9 times.I.e. /home/song2.mp3, /home/song3.mp3
> > > /home/song4.mp3, etc. I suppose the period, ".", would be the
> > > delimiter. I've put down the basics but I'm stumped with the body of
> > > the program. Any help would be appreciated. I posted the little bit
> > > I came up with.
> > >
> > > #!/usr/bin/perl
> > >
> > >
> > > use strict;
> > > use warnings;
> > > print "Input mp3 name ";
> > > my $mp3;
> > >
> > > # Maybe chomp the newline here[/color]
> >
> > There is no newline if you have entered the filename on the command
> > line. What you entered is in $ARGV[0] (you should check $#ARGV to see
> > if you actually entered anything).
> >[color=darkred]
> > >
> > > # Find the delimiter and increment the filename[/color]
> >
> > You might have other periods in the filename, so it is best to look for
> > the substring '.mp3' in a regular expression.
> >[color=darkred]
> > >
> > > # Loop it 9 times[/color]
> >
> > You want to use a regular expression that matches a number before the
> > '.mp3', extracts the number and whatever was before it, and increments
> > the number in a loop. Something like this will work for any number of
> > digits in the number:
> >
> > #!/opt/perl/bin/perl
> > use strict;
> > use warnings;
> > if( $ARGV[0] =~ /(\S+)(\d+)\.mp3 $/ ) {
> > my $base = $1;
> > my $num = $2;
> > print $base . $num++ . ".mp3\n" for (1..9) ;
> > }
> >
> > See perldoc perlre[/color]
>
> The initial code actually works pretty well. I did modify it to look
> for ".mp3" instead of just ".". I've also tried to modify it to write
> it's output to a file instead of STDOUT with no luck. I've been
> placing "printf OUTPUTFILE "$path";" inside the loop but receive
> errors. I would like to increment the original name and have it write
> to a file. Right now the script of course writes the last result
> only, i.e. /home/mysongs/mysong10.mp3". Any ideas?[/color]

Are you still having problems? If so, it would be best to post the
exact code you are using, but only as much as required to demonstrate
the problem. Are you having trouble writing to a file? What errors are
you receiving?

By the way, this newsgroup is defunct. Try comp.lang.perl. misc in the
future.

Have perl increment a number that shows up before a delimiter

Have perl increment a number that shows up before a delimiter

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