HOW: Check string existence in a file.

[mrlawrencelam]

Seeing my questin below and you will know that I don't know much about
Perl. But I urgently need a simple Perl script that do this task:

How do I write a little Perl script to read a file and check for a
string?

1) Read the file "aaa.txt".
2) If string "xxx yyy zzz" is in that file, then do action 1.
3) If not, then do action 2.

Thanks.

 

[Eric Schwartz]

Seeing my questin below and you will know that I don't know much about
Perl. But I urgently need a simple Perl script that do this task:

This newsgroup is not for writing Perl programs for people (though you
may luck out and someone will do it anyway, because they're
sufficiently bored). It's about discussing Perl programs. So please
read the documentation first, and try and write some code; we're much
more inclined to help someone who's made a little effort than someone
who says, "I need you to write my code for me, for free, fast!".

How do I write a little Perl script to read a file and check for a
string?

1) Read the file "aaa.txt".

perldoc -f open
perldoc perlop (search for "I/O Operators")

2) If string "xxx yyy zzz" is in that file, then do action 1.
3) If not, then do action 2.

perldoc perlsyn

I hope these documentation references are helpful.

-=Eric

 

[Tad McClellan]

Seeing my questin below and you will know that I don't know much about
Perl. But I urgently need a simple Perl script

http://lists.cpan.org/showlist.cgi?name=jobs


How do I write a little Perl script to read a file and check for a
string?

Show us what you have tried so far, and we will help you fix it.

 

[John W. Krahn]

Seeing my questin below and you will know that I don't know much about
Perl. But I urgently need a simple Perl script that do this task:

How do I write a little Perl script to read a file and check for a
string?

1) Read the file "aaa.txt".
2) If string "xxx yyy zzz" is in that file, then do action 1.
3) If not, then do action 2.

*UNTESTED*

#!/usr/bin/perl
use warnings;
use strict;

my $file = 'aaa.txt';
open my $fh, '<', $file or die "Cannot open $file: $!";

my $found;
while ( <$fh> ) {
$found += /xxx yyy zzz/;
}

if ( $found ) {
do_action_1();
}
else {
do_action_2();
}

__END__



John

 

[John Bokma]

my $found;
while ( <$fh> ) {
$found += /xxx yyy zzz/;
}

my $found = 0;
while ( <$fh> ) {

/xxx yyy zzz/ or next;
$found = 1;
last;
}

 

[William James]

How do I write a little Perl script to read a file and check for a
string?

1) Read the file "aaa.txt".
2) If string "xxx yyy zzz" is in that file, then do action 1.
3) If not, then do action 2.

In Ruby:

found = false
open("aaa.txt"){ |filehandle|
filehandle.each{ |line|
found = true and break if line.index("xxx yyy zzz") }
}
if found
puts 'yes'
else
puts 'no'
end

 

[Mark Clements]

In Ruby:

found = false
open("aaa.txt"){ |filehandle|
filehandle.each{ |line|
found = true and break if line.index("xxx yyy zzz") }
}
if found
puts 'yes'
else
puts 'no'
end

This has no relevance to the question. There are hundreds of languages
out there, each of which may or may not have advantages or disadvantages
over Perl in certain scenarios, but giving solutions to Perl questions
using whatever happens to be somebody's pet language isn't very helpful.

Mark

 

[John Bokma]

This has no relevance to the question.

William James is a troll, ignore it.