in reply to Seperating individual lines of a file

You can put your sample data inside <code></code> tags.

It would also be helpful if you put the code you've attempted for this inside those tags, too, so we can see where your code is not doing what you expect.



--chargrill
$/ = q#(\w)# ; sub sig { print scalar reverse join ' ', @_ } + sig map { s$\$/\$/$\$2\$1$g && $_ } split( ' ', ",erckha rlPe erthnoa stJu +" );

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Re^2: Seperating individual lines of a file
by tgrossner (Novice) on Feb 02, 2006 at 22:03 UTC
    Here my start on the code:
    #!/usr/bin/perl open ORIGFILE, "noc.060202_13"; #print ORIGFILE; push(@DATA,<ORIGFILE>); foreach my $LINE (@DATA){ open FH, "$LINE[0]"; print FH $LINE; close FH; }
    after setting up the foreach loop, i can print $LINE to STDOUT and see each line, but i cant pull out the first element as $LINE[0] to name the file, seemingly.

      First, that's an interesting use of push - you could just do @DATA=<ORIGFILE>;, but I don't think that's a big deal.

      Second, you'll find that you'll want to open your file for writing by using the open, FILEHANDLE, ">filename" nomenclature.

      Third, as written, your code will open a file called "host1 BUNCHOFDATAINALINE". You might want to split( /pattern/, expression ) each line of the file so you can separately refer to the separate pieces of data, like ( $HOSTNAME, $SOMEDATA ).



      --chargrill
      $/ = q#(\w)# ; sub sig { print scalar reverse join ' ', @_ } + sig map { s$\$/\$/$\$2\$1$g && $_ } split( ' ', ",erckha rlPe erthnoa stJu +" );
        ok, on the split function, can i split $line into two sections, one being the first 16 characters, then name the file via this string of characters?
      Something that chargrill didn't mention, but might be an issue:

      Doing a file open and file close for every line can get really expensive and time consuming if there happen to be thousands of lines of input.

      Perl allows you to store file handles in a hash, so you can open a new file each time you see a new "hostname" string, and just re-use that handle whenever you see the same name again:

      # set $listfile to some constant, or to $ARGV[0] (and supply the file +name # as a command-line arg when you run the script) my %outfh; # hash to hold output file handles open ORIGFILE, $listfile or die "$listfile: $!"; while ( <ORIGFILE> ) { my ( $host, $data ) = split " ", $_, 2; if ( ! exists( $outfh{$host} )) { open( $outfh{$host}, ">", $host ) or die "$host: $!"; } print $outfh{$host} $data; } # perl will flush and close output files when done
      Of course, if there are lots of different host names in the input file (or if there is something really wrong and unexpected in the list file contents), the script would die when it tries to open too many file handles.
        I am trying out your code; I replaced the $listfile with $ARGV[0].
        #!/usr/bin/perl # set $listfile to some constant, or to $ARGV[0] (and supply the file #+name # as a command-line arg when you run the script) my %outfh; # hash to hold output file handles open ORIGFILE, $ARGV[0] or die "$ARGV[0]: $!"; while ( <ORIGFILE> ) { my ( $host, $data ) = split " ", $_, 2; if ( ! exists( $outfh{$host} )) { open( $outfh{$host}, ">", $host ) or die "$host: $!"; } print $outfh{$host} $data; } # perl will flush and close output files when done
        But this produces a syntax error of
        Scalar found where operator expected at ./nocsplit.pl line 17, near "} + $data" (Missing operator before $data?) syntax error at ./nocsplit.pl line 17, near "} $data" Execution of ./nocsplit.pl aborted due to compilation errors.
        It seems to not like the
        print to $outfh{$host} $data;

      People generally do

      use strict; use warnings;

      nowadays, and that's the single best piece of advice I can give you!

      Also, people do

      my @DATA=<ORIGFILE>;

      but then they also prefer to avoid slurping in files all at once, and they iterate on the lines instead with a while loop rather than with a for one:

      while (my $line=<ORIGFILE>) { # ...

      In any case you have to specify '>' mode in open for writing (and '>>' for appending). More generally I recommend you to stick with the three args form of open and lexical handles, and always check the return value:

      open my $in, '<', "whatever" or die "can't open `whatever': $!\n"; open my $out, '>', "whatever" or die "can't open `whatever': $!\n";