NetNews Usenet Archive 1992 #30/NN_1992_30.iso/spool/comp/lang/perl/7551

Text File | 1992-12-21 | 1.8 KB | 61 lines

Newsgroups: comp.lang.perl
Path: sparky!uunet!psinntp!balltown!cabot!rodney
From: rodney@cabot (Rodney Peck)
Subject: Re: Feature request for perl V
Message-ID: <[e-mail]>
Sender: [e-mail]
Nntp-Posting-Host: cabot
Organization: New York State Institute for Sebastian Cabot Studies
X-Newsreader: Tin 1.1 PL4
References: <[e-mail]>
Date: Fri, 18 Dec 1992 21:50:39 GMT
Lines: 47

#!/bin/perl

@lines = (
"[e-mail] (Wayne Folta) writes:",
": Could grep have an added option/mode that would allow me to get an array",
": of indices instead of an array of items? I want to read a file into an",
": array, then do some greps in the array, some calculations, and then if",
": everything is right, make a couple of changes in the array, then write it",
": back out to the file. If I could do this:",
": ",
":    @line_numbers = grepi (/IN A/, @lines) ;",
": ",
": I'd be pretty happy. How's it sound?");

# I think the subroutine below does what you want.  I can't see any reason
# to make this an internal function.  I imagine the internal version would
# do roughly the same thing.
#  rodney
#
#  here's the output of grepi looking for " array" in the above message:
#
# cabot> perl f
# 1, 2, 3, 4
# : Could grep have an added option/mode that would allow me to get an array
# : of indices instead of an array of items? I want to read a file into an
# : array, then do some greps in the array, some calculations, and then if
# : everything is right, make a couple of changes in the array, then write it
#


@line_numbers = &grepi("/ array/",@lines);

print join(", ", @line_numbers),"\n";
grep ((print @lines[$_],"\n"), @line_numbers);

sub grepi {
local ($exp,@ar) = @_;
local (@ans,$_);
local ($count) = 0;

  foreach $_ (@ar)
  {
    push(@ans,$count) if eval($exp);
    $count++;
  }
  @ans;
}