Merge pull request #227 from mknos/head-dir

head versus directories
briandfoy · Sep 6, 2023 · 172621d · 172621d
2 parents dc29f7a + 61d43f3
commit 172621d
Showing 1 changed file with 46 additions and 12 deletions.
diff --git a/bin/head b/bin/head
@@ -13,32 +13,66 @@ License: perl
 
 
 use strict;
-use Getopt::Std;
 
-my ($VERSION) = '1.3';
+use File::Basename qw(basename);
+use Getopt::Std qw(getopts);
 
-my %opt;
-getopts('n:', \%opt) or die("usage: $0 [-n count] [files ...]\n");
+use constant EX_SUCCESS => 0;
+use constant EX_FAILURE => 1;
 
-my $count = (defined $opt{'n'}) ? $opt{'n'} : 10;
+my $Program = basename($0);
+my ($VERSION) = '1.3';
 
-die "invalid number `$count'\n" if $count =~ /\D/;
+my %opt;
+unless (getopts('n:', \%opt)) {
+    warn "usage: $Program [-n count] [file ...]\n";
+    exit EX_FAILURE;
+}
+my $count;
+if (defined $opt{'n'}) {
+    $count = $opt{'n'};
+    if ($count =~ m/\D/a) {
+        warn "$Program: invalid number '$count'\n";
+        exit EX_FAILURE;
+    }
+    if ($count == 0) {
+        warn "$Program: count is too small\n";
+        exit EX_FAILURE;
+    }
+} else {
+    $count = 10;
+}
 
 @ARGV = '-' unless @ARGV;
+my $err = 0;
+my $sep = 0;
 
 foreach my $file (@ARGV) {
     my ($fh, $is_stdin);
     if ($file eq '-') {
         $fh = *STDIN;
         $is_stdin = 1;
+    } else {
+        if (-d $file) {
+            warn "$Program: '$file' is a directory\n";
+            $err++;
+            next;
+        }
+        unless (open $fh, '<', $file) {
+            warn "$Program: $file: $!\n";
+            $err++;
+            next;
+        }
     }
-    if (!$is_stdin && !open($fh, '<', $file)) {
-        warn "$0: $file: $!\n";
-        next;
-    }
+
     if (scalar(@ARGV) > 1) {
         my $fname = $is_stdin ? 'standard input' : $file;
-        print "==> $fname <== \n";
+        if ($sep == 0) {
+            $sep = 1;
+        } else {
+            print "\n";
+        }
+        print "==> $fname <==\n";
     }
     foreach (1 .. $count) {
         my $line = <$fh>;
@@ -47,7 +81,7 @@ foreach my $file (@ARGV) {
     }
     close($fh) unless $is_stdin;
 }
-
+exit ($err ? EX_FAILURE : EX_SUCCESS);
 
 __END__