tabdata/td-add-headers

   1 #!/usr/bin/env perl
   2
   3 =pod
   4
   5 =head1 NAME
   6
   7 td-add-headers - Add headers to the tabular data stream and pass through the rows.
   8
   9 =head1 SYNOPSIS
  10
  11 td-add-headers I<COLNAME_1> I<COLNAME_2> ...
  12
  13 =head1 DESCRIPTION
  14
  15 Add header row to the tabular data stream. Headers names will be the
  16 ones specified in the command line arguments, from the left-most 1-by-1.
  17
  18 If there are more fields in the first data row, then additional columns
  19 will be added with names like "COL4", "COL5", etc. by the index number
  20 of the column counting from 1.
  21 This may be prevented by --no-extra-columns option.
  22
  23 =head1 OPTIONS
  24
  25 =over 4
  26
  27 =item -x, --extra-columns
  28
  29 Give a name also to those columns which are not given name in the command parameters.
  30
  31 =item -X, --no-extra-columns
  32
  33 Do not add more columns than specified in the command parameters.
  34
  35 =back
  36
  37 =head1 EXAMPLE
  38
  39  who | td-trans | td-add-headers USER TTY DATE TIME COMMENT
  40
  41 =cut
  42
  43 $OptAddExtraColumns = 1;
  44 %OptionDefs = (
  45         'x|extra-columns' => sub { $OptAddExtraColumns = 1; },
  46         'X|no-extra-columns' => sub { $OptAddExtraColumns = 0; },
  47 );
  48
  49 no if ($] >= 5.018), 'warnings' => 'experimental::smartmatch';
  50 do '/usr/lib/tool/perl5/tabdata/common.pl' or die "$@";
  51
  52 @Headers = @ARGV;
  53
  54 if($OptAddExtraColumns)
  55 {
  56         # complete the number of headers to be as many as fields are there in the first row.
  57
  58         $first_line = <STDIN>;
  59         chomp $first_line;
  60         $num_fields = scalar split $FS, $first_line;
  61         for my $n ((1 + scalar @Headers)..$num_fields)
  62         {
  63                 push @Headers, "COL$n";
  64         }
  65 }
  66 else
  67 {
  68         $first_line = undef;
  69 }
  70
  71 print join($FS, @Headers).$RS;
  72 print $first_line.$RS if defined $first_line;
  73 while(<STDIN>)
  74 {
  75         print;
  76 }