Versions Compared

Old Version 2

changes.mady.by.user Keith Sinclair

Saved on

compared with

New Version 3

changes.mady.by.user Keith Sinclair

Saved on

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.

...

Perl if statement

 

Code Block
themeEmacs
 use strict;
 my $string = "this is a string";
 if ( $string eq "string" ) {
  print "$string is the same as \"string\"\n";
 }
 elsif ( $string =~ /string/ ) {
  print "regex match $string has \"string\" in it\n";
 }
 elsif ( $string == 100 ) {
  print "$string is the number 100\n";
 }
 else {
  print "Else Nothing\n";
}

Perl Loops -> While

Code Block
while (condition) {
  # do something
}

Perl Loops -> for

Code Block
use strict;
my @array = (1, 2, 3, 4, 5, 6);
for ( my $i = 0; $i <= $#array; ++$i ) {
  print “i=$array[$i]\n”;
}

Perl Loops -> foreach

Code Block
use strict;
my @array = (1, 2, 3, 4, 5, 6);
foreach my $i ( @array ) {
  print “i=$i\n”;
}

Open a file and loop through

Code Block
use strict;
my $match = "blah";
my $file = "textfile.txt";
my $lines = 0;
open (DATA, $file) or die "ERROR with $file. $!";
while (<DATA>) {
  chomp; # not necessary but gets rid of trailing spaces and newlines.
  if ( $_ =~ /$match/) {
    print "$lines: $_\n"; 
  }
  ++$lines;
}