in reply to Re: Adding a TAB after a certain ammount of characters
in thread Adding a TAB after a certain ammount of characters

Attacking the insertions in reverse order from the right-hand side means you don't have to increment your position by one for each successive insertion. Swings and roundabouts really but sometimes a useful technique.

$ perl -Mstrict -Mwarnings -E '
> my $text =
>    q{2013020400000000006810083610022013068100200220130688000200494};
> my @offs = ( 17, 6, 31, 3, 3 );
> my @cums = ( 0 );
> push @cums, $_ + $cums[ -1 ] for @offs;
> substr $text, $_, 0, q{-} for reverse @cums[ 1 .. $#cums ];
> say $text;'
20130204000000000-068100-8361002201306810020022013068800-020-049-4

[download]

Here's the code without the PS2 prompt for easier copy'n'paste, as requested by /msg in respect of another post.

perl -Mstrict -Mwarnings -E '
my $text =
   q{2013020400000000006810083610022013068100200220130688000200494};
my @offs = ( 17, 6, 31, 3, 3 );
my @cums = ( 0 );
push @cums, $_ + $cums[ -1 ] for @offs;
substr $text, $_, 0, q{-} for reverse @cums[ 1 .. $#cums ];
say $text;'

[download]

I hope this is of interest.

Cheers,

JohnGG

Replies are listed 'Best First'.
Re^3: Adding a TAB after a certain ammount of characters
by biancoari (Initiate) on Apr 17, 2013 at 03:11 UTC

    Hi, I've tried to use it exactly as you put it and I got:

    biancoari@biancoari ~/Desktop $ perl perl1.pl
    String found where operator expected at perl1.pl line 8, near "say $text;'"
    (Might be a runaway multi-line '' string starting on line 1)
    (Missing semicolon on previous line?)
    syntax error at perl1.pl line 8, near "say $text;'"
    Execution of perl1.pl aborted due to compilation errors.

    Besides I have another question what I am trying to modify is a txt file with several lines (like the one on the example, they are all the same) any clue on that?

[reply]

      Please show us your perl1.pl script inside <code> and </code> tags so we can see where you are going wrong. As for working on a multi-line file, calculate the offsets, open your file then do something like

      while ( <$inputFH> )
{
    foreach my $offset ( reverse @cums[ 1 .. $#cums ] )
    }
        substr $_, $offset, 0, q{-};
    }
    print;
}

      [download]

      I hope this moves you forward.

      Update: Code modified to replace for statement modifier with an explicit loop, thanks choroba.

      Cheers,

      JohnGG

[reply]
[d/l]
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        Now the file looks like this perl1.pl script looks like this (after some modifications I did from reading the replies

         #!/usr/local/bin/perl 
perl -Mstrict -Mwarnings -E 
my $text =
   q{2013020400000000006810083610022013068100200220130688000200494};
my @offs = ( 17, 6, 31, 3, 3 );
my @cums = ( 0 );
push @cums, $_ + $cums[ -1 ] for @offs;
substr $text, $_, 0, q{-} for reverse @cums[ 1 .. $#cums ];
say $text;

        [download]

        And the reply I get from running the script is:

        biancoari@biancoari ~/Desktop $ perl perl1.pl
        syntax error at perl1.pl line 2, near "E
        my "
        Execution of perl1.pl aborted due to compilation errors.

        I will add the

        open(FILE, "filename.txt") or die "Could not open file: $!"

        and modify the text, any idea if I am heading the right direction?

[reply]
[d/l]
[select]
      syntax error at perl1.pl line 8, near "say $text;'"

      Note the single-quote just after the ; (semicolon) in "say $text;'". This closes the quoted code that began with an opening single-quote just after the -E on the first line of the command line invocation in johngg's reply. Get rid of that closing single-quote if you are running the code from a file and things will probably work better.

[reply]

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