X-Git-Url: http://git.shiar.nl/barcat.git/blobdiff_plain/46f1edad6cf059eaef351f950e2f067c05871563..571ed1a9a73129dff78c4d04333949605b91c273:/barcat

diff --git a/barcat b/barcat
index 82f0fff..ce3f788 100755
--- a/barcat
+++ b/barcat
@@ -39,8 +39,9 @@ GetOptions(\%opt,
 	'limit|L:s' => sub {
 		my ($optname, $optval) = @_;
 		$optval ||= 0;
+		$optval =~ /\A-[0-9]+\z/ and $optval .= '-';  # tail shorthand
 		($opt{hidemin}, $opt{hidemax}) =
-		$optval =~ m/\A (?: ([0-9]+)? - )? ([0-9]+)? \z/ or die(
+		$optval =~ m/\A (?: (-? [0-9]+)? - )? ([0-9]+)? \z/ or die(
 			"Value \"$optval\" invalid for option limit",
 			" (range expected)\n"
 		);
@@ -81,33 +82,7 @@ GetOptions(\%opt,
 		exit;
 	},
 	'usage|h' => sub {
-		local $/ = undef;  # slurp
-		my $pod = readline *DATA;
-		$pod =~ s/^=over\K/ 25/;  # indent options list
-		$pod =~ s{
-			^=item \h \N*\n\n \N*\n \K  # first line
-			(?: (?: ^=over .*? ^=back\n )? (?!=) \N*\n )*
-		}{\n}g;  # abbreviate options
-		$pod =~ s/[.,](?=\n)//g;  # trailing punctuation
-		$pod =~ s/^=item\ \K(?=--)/____/g;  # align long options
-		# abbreviate <variable> indicators
-		$pod =~ s/\Q>.../s>/g;
-		$pod =~ s/<(?:number|count|seconds)>/N/g;
-		$pod =~ s/<character(s?)>/\Uchar$1/g;
-		$pod =~ s/\Q | /|/g;
-		$pod =~ s/(?<!\w)<([a-z]+)>/\U$1/g;  # uppercase
-
-		require Pod::Usage;
-		my $parser = Pod::Usage->new(USAGE_OPTIONS => {
-			-indent => 2, -width => 78,
-		});
-		$parser->select('SYNOPSIS', 'OPTIONS');
-		$parser->output_string(\my $contents);
-		$parser->parse_string_document($pod);
-
-		$contents =~ s/\n(?=\n\h)//msg;  # strip space between items
-		$contents =~ s/^\ \ \K____/    /g;  # nbsp substitute
-		print $contents;
+		/^=/ ? last : print for readline *DATA;  # text between __END__ and pod
 		exit;
 	},
 	'help|?'  => sub {
@@ -205,13 +180,24 @@ sub color {
 
 sub show_lines {
 
-state $nr = $opt{hidemin};
-@lines or return;
+state $nr =
+	$opt{hidemin} < 0 ? @lines + $opt{hidemin} + 1 :
+	$opt{hidemin};
 @lines > $nr or return;
 
+my $limit = $#lines;
+if (defined $opt{hidemax}) {
+	if ($opt{hidemin} and $opt{hidemin} < 0) {
+		$limit -= $opt{hidemax} - 1;
+	}
+	else {
+		$limit = $opt{hidemax} - 1;
+	}
+}
+
 @order = sort { $b <=> $a } @order unless tied @order;
 my $maxval = $opt{maxval} // (
-	$opt{hidemax} ? max grep { length } @values[0 .. $opt{hidemax} - 1] :
+	$opt{hidemax} ? max grep { length } @values[$nr .. $limit] :
 	$order[0]
 ) // 0;
 my $minval = $opt{minval} // min $order[-1] // (), 0;
@@ -274,8 +260,7 @@ say(
 	color(0),
 ) if $opt{header};
 
-while ($nr <= $#lines) {
-	$nr >= $opt{hidemax} and last if defined $opt{hidemax};
+while ($nr <= $limit) {
 	my $val = $values[$nr];
 	my $rel = length $val && $range && ($val - $minval) / $range;
 	my $color = !length $val || !$opt{palette} ? undef :
@@ -316,9 +301,15 @@ say $opt{palette} ? color(0) : '' if $opt{spark};
 
 sub show_stat {
 	if ($opt{hidemin} or $opt{hidemax}) {
-		printf '%.8g of ', $opt{'sum-format'}->(sum(grep { length }
-			@values[$opt{hidemin} .. ($opt{hidemax} || @lines) - 1]
-		) // 0);
+		my $linemin = $opt{hidemin};
+		my $linemax = ($opt{hidemax} || @lines) - 1;
+		if ($linemin < 0) {
+			$linemin += @lines;
+			$linemax = @lines - $linemax;
+		}
+		printf '%.8g of ', $opt{'sum-format'}->(
+			sum(grep {length} @values[$linemin .. $linemax]) // 0
+		);
 	}
 	if (@order) {
 		my $total = sum @order;
@@ -345,6 +336,37 @@ sub show_exit {
 show_exit();
 
 __END__
+Usage:
+  barcat [OPTIONS] [FILES|NUMBERS]
+
+Options:
+  -a, --[no-]ascii         Restrict user interface to ASCII characters
+  -c, --[no-]color         Force colored output of values and bar markers
+  -f, --field=(N|REGEXP)   Compare values after a given number of whitespace
+                           separators
+      --header             Prepend a chart axis with minimum and maximum
+                           values labeled
+  -H, --human-readable     Format values using SI unit prefixes
+  -t, --interval[=(N|-LINES)]
+                           Output partial progress every given number of
+                           seconds or input lines
+  -l, --length=[-]SIZE[%]  Trim line contents (between number and bars)
+  -L, --limit[=(N|-LAST|START-[END])]
+                           Stop output after a number of lines
+      --graph-format=CHAR  Glyph to repeat for the graph line
+  -m, --markers=FORMAT     Statistical positions to indicate on bars
+      --min=N, --max=N     Bars extend from 0 or the minimum value if lower
+      --palette=(PRESET|COLORS)
+                           Override colors of parsed numbers
+      --spark[=CHARS]      Replace lines by sparklines
+  -s, --stat               Total statistics after all data
+  -u, --unmodified         Do not reformat values, keeping leading whitespace
+      --value-length=SIZE  Reserved space for numbers
+  -w, --width=COLUMNS      Override the maximum number of columns to use
+  -h, --usage              Overview of available options
+      --help               Full documentation
+      --version            Version information
+
 =encoding utf8
 
 =head1 NAME
@@ -422,9 +444,13 @@ unless C<--length=0>.
 Prepend a dash (i.e. make negative) to enforce padding
 regardless of encountered contents.
 
-=item -L, --limit[=(<count> | <start>-[<end>])]
+=item -L, --limit[=(<count> | -<last> | <start>-[<end>])]
 
 Stop output after a number of lines.
+A single value indicates the last line number (like C<head>),
+or first line counting from the bottom if negative (like C<tail>).
+A specific range can be given by two values.
+
 All input is still counted and analyzed for statistics,
 but disregarded for padding and bar size.