cat: add raw mode (#638)

* Implement idea from BSD version of cat: bypass input processing if none of options -b -e -n -s -t & -v are provided

Author: mknos

bin/cat

@@ -22,20 +22,24 @@ use constant EX_FAILURE => 1;
 our $VERSION = '1.3';
 my $Program = basename($0);
 
-getopts('benstuv', \my %options)  or do {
+my %opt;
+getopts('benstuv', \%opt)  or do {
     warn "usage: $Program [-benstuv] [file ...]\n";
     exit EX_FAILURE;
 };
 
-my $ends              = exists $options{'e'};
-my $tabs              = exists $options{'t'};
-my $nonprinting       = exists $options{'v'} || $ends || $tabs;
-my $squeeze_empty     = exists $options{'s'};
-my $number_lines      = $options{'n'} && !$options{'b'};
-my $number_non_blanks = exists $options{'b'};
+my $ends              = $opt{'e'};
+my $tabs              = $opt{'t'};
+my $nonprinting       = $opt{'v'} || $ends || $tabs;
+my $squeeze_empty     = $opt{'s'};
+my $number_lines      = $opt{'n'} && !$opt{'b'};
+my $number_non_blanks = $opt{'b'};
+
+my $cook = grep {$_ || ()} @opt{'b', 'e', 'n', 's', 't', 'v'};
+my $cat = $cook ? \&cook_file : \&raw_file;
 
 # Unbuffer output for -u.
-$| = exists $options{'u'};
+$| = 1 if $opt{'u'};
 
 my $was_empty = 0;
 my $count     = 0;
@@ -70,9 +74,28 @@ sub do_file {
             return 1;
         }
     }
+    $cat->($fh);
 
-    while (<$fh>) {
+    if ($name ne '-' && !close($fh)) {
+        warn "$Program: failed to close '$name': $!\n";
+        return 1;
+    }
+    return 0;
+}
+
+sub raw_file {
+    my $fh = shift;
+    my $BUFSZ = 8192;
+    my $buf;
+    while (read $fh, $buf, $BUFSZ) {
+	print $buf;
+    }
+}
+
+sub cook_file {
+    my $fh = shift;
 
+    while (<$fh>) {
         if ($squeeze_empty) {
             my $is_empty = /^$/;
             if ($is_empty && $was_empty) {
@@ -96,11 +119,6 @@ sub do_file {
         }
         print;
     }
-    if ($name ne '-' && !close($fh)) {
-        warn "$Program: failed to close '$name': $!\n";
-        return 1;
-    }
-    return 0;
 }
 
 __END__