Re: Trying to make a search

There are several problems with your code... As mdillon already pointed out you should chomp $input to remove the cr/lf. The other major error is in the following line:

print "${line}";
[download]

That should read $line and not ${line}.

Now I've fixed your code (you can see my fixes below) to make it functional, but it still isn't very "perl" looking and has some needless code.

#!/usr/bin/perl

my $ans;
my $currentline;
my @data;

print "Letter? ";
$letter = <STDIN>;
chomp $letter;
open (DATA, "books.txt");
@data = <DATA>;
$currentline = 0;
foreach $data(@data) {
  $line = $data[$currentline];         # there are brackets around $cu
+rrentline
  if ($line =~ /^$letter/i) {
    print $line;
  }
  $currentline++
}
[download]

Now here is a much more "perl-looking" implementation:

#!/usr/bin/perl -w

use strict;

print "Letter? ";
my $letter = <STDIN>;   
chomp $letter;
open (DATA, "books.txt") or die "error opening file $!";
my $line;
foreach $line(<DATA>) {
  if ($line =~ /^$letter/i) {
    print $line;
  }
}  
close DATA;
[download]

Comment on Re: Trying to make a search Select or Download Code

Replies are listed 'Best First'.
RE: Re: Trying to make a search by ishamael (Beadle) on Jun 04, 2000 at 02:02 UTC
hehe, on the idea of more "perl looking", in my opinion: `#/usr/bin/perl -w use strict; print "Letter: "; chomp(my $letter = <STDIN>); open(DATA, "books.txt") or die "error opening file $!"; while(<DATA>) { if (/^$letter/i) { print; } }` [download] charlie schmidt ishamael@themes.org www.diablonet.net/~ishamael/	[reply] [d/l]
Re: Trying to make a search by link (Novice) on Jun 04, 2000 at 01:12 UTC
Since we're already picking nits and playing reductionists; here's removing a little more redundancy. Hopefully without crossing over and becoming obscure (versions involving map()/grep()-combos deliberately left as an excersice for the reader ;D) #!/usr/bin/perl -w use strict; print "Letter? "; my $letter = <STDIN>; chomp $letter; open DATA, "books.txt" or die "open(books.txt) returned: $!\n"; foreach my $line (<DATA>) { print $line if $line =~ /^$letter/i; } close DATA;	[reply]
RE: Re: Trying to make a search by Alokito (Novice) on Jun 05, 2000 at 10:19 UTC
Grep is not obscure. It is much clearer than dumb loops that are really just low level implementations of list operations. `#!/usr/bin/perl -w use strict; print "Letter? "; chomp(my $letter = <STDIN>); open DATA, "books.txt" or die "open(books.txt) returned: $!\n"; print grep {/^$letter/io} <DATA>;` [download] Of course, I kind of like something like `perl -e 'print grep {/^a/io} <>' /usr/dict/words` [download] Try it, you'll like it too!	[reply] [d/l] [select]
RE: Re: Trying to make a search by Anonymous Monk on Jun 04, 2000 at 08:13 UTC
> The other major error is in the following line: ><BR > `print "${line}";` > > That should read $line and not ${line}. Actually, it doesn't make a difference. ${line} is just as good (and sometimes better) as $line in double-quotish contexts.	[reply] [d/l]