filter.pl
Download filter.pl
1: #!/usr/bin/perl -TW
2: #
3: # filter.pl - This demo perl program shows how to read a filename
4: # from the command line, open the file for reading, do something
5: # to it (convert to all uppercase), and send the results to stdout.
6: # As an extra, notice how if no filename is supplied then STDIN
7: # is used instead.
8: #
9: # Written 3/2007 by Wayne Pollock, Tampa Florida USA
10:
11: if ( @ARGV )
12: { $filename = $ARGV[0];
13: } else {
14: $filename = "-";
15: }
16:
17: open( FILE, "< $filename" ) or die "$filename: $!";
18:
19: $filename = "STDIN" if ( $filename eq "-" );
20:
21: print "filename: $filename\n";
22:
23: while ( <FILE> )
24: {
25: tr/a-z/A-Z/;
26: print;
27: }
28:
29: print "The end.\n";
30:
31: close( FILE );