X-Git-Url: http://git.shiar.nl/barcat.git/blobdiff_plain/723ee2afb91020afe0bb270f91c76bef283b6643..d4ac8976088cb8279ca83cfe7c55142a491b1f02:/barcat

diff --git a/barcat b/barcat
index 1ffdeda..79d8679 100755
--- a/barcat
+++ b/barcat
@@ -40,19 +40,42 @@ GetOptions(\%opt,
 		$opt{trim} = $optval;
 	},
 	'value-length=i',
-	'hidemin=i',
-	'hidemax=i',
 	'minval=f',
 	'maxval=f',
 	'limit|L:s' => sub {
 		my ($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(
+		$optval =~ s/[+]/--/;
+		my ($start, $end) =
+		$optval =~ m/\A (?: (-? [0-9]+)? - )? (-? [0-9]+)? \z/ or die(
 			"Value \"$optval\" invalid for option limit",
 			" (range expected)\n"
 		);
+		$start ||= 1;
+		$start--;
+		s/\A-0*\z// and $_ ||= undef for $end // ();
+
+		$opt{hidemin} = sub {
+			my ($lines) = @_;
+			if ($start < 0) {
+				return max(0, $lines + $start + 2);
+			}
+			return $start;
+		} if $start;
+		$opt{hidemax} = sub {
+			my ($limit, $offset) = @_;
+			if ($end < 0) {
+				return $offset - $end - 1; # count
+			}
+			elsif ($start < 0) {
+				return $limit - $end + 1; # bottom
+			}
+			elsif ($end <= $limit) {
+				return $end - 1; # less
+			}
+			return $limit;
+		} if defined $end;
 	},
 	'log|e!',
 	'header!',
@@ -132,7 +155,6 @@ $opt{palette} //= $opt{color} && [31, 90, 32];
 $opt{indicators} = [split //, $opt{indicators} ||
 	($opt{ascii} ? ' .oO' : $opt{spark} ? ' ▁▂▃▄▅▆▇█' : ' ▏▎▍▌▋▊▉█')
 ] if defined $opt{indicators} or $opt{spark};
-$opt{hidemin} = ($opt{hidemin} || 1) - 1;
 $opt{input} = (@ARGV && $ARGV[0] =~ m/\A[-0-9]/) ? \@ARGV : undef
 	and undef $opt{interval};
 
@@ -214,20 +236,10 @@ sub color {
 
 sub show_lines {
 
-state $nr =
-	$opt{hidemin} < 0 ? max(0, @lines + $opt{hidemin} + 1) :
-	$opt{hidemin};
+state $nr = $opt{hidemin} ? $opt{hidemin}->($#lines) : 0;
 @lines > $nr or return;
 
-my $limit = $#lines;
-if (defined $opt{hidemax}) {
-	if ($opt{hidemin} and $opt{hidemin} < 0) {
-		$limit -= $opt{hidemax} - 1;
-	}
-	elsif ($opt{hidemax} <= $limit) {
-		$limit = $opt{hidemax} - 1;
-	}
-}
+my $limit = $opt{hidemax} ? $opt{hidemax}->($#lines, $nr) : $#lines;
 
 @order = sort { $b <=> $a } @order unless tied @order;
 my $maxval = $opt{maxval} // (
@@ -239,8 +251,8 @@ my $range = $maxval - $minval;
 $range &&= log $range if $opt{log};
 my $lenval = $opt{'value-length'} // max map { length } @order;
 my $len    = defined $opt{trim} && $opt{trim} <= 0 ? -$opt{trim} + 1 :
-	max map { length $values[$_] && length $lines[$_] }
-		0 .. min $#lines, $opt{hidemax} || ();  # left padding
+	max(map { length $values[$_] && length $lines[$_] } $nr .. $limit)
+	// 0;  # left padding
 my $size   = defined $opt{width} && $range &&
 	($opt{width} - $lenval - $len - !!$opt{indicators});  # bar multiplication
 
@@ -263,10 +275,10 @@ if ($opt{markers} and $size > 0) {
 				return $func;
 			}
 			elsif ($func =~ /\A\/($float)\z/) {
-				my @range = $1;
-				#TODO log
-				for (my $next = $1; $next < $maxval; $next += $range[0]) {
-					push @range, $next;
+				my @range = my $multiple = my $next = $1;
+				while ($next < $maxval) {
+					$multiple *= 10 if $opt{log};
+					push @range, $next += $multiple;
 				}
 				return @range;
 			}
@@ -362,16 +374,12 @@ say $opt{palette} ? color(0) : '' if $opt{spark};
 
 sub show_stat {
 	if ($opt{hidemin} or $opt{hidemax}) {
-		my $linemin = $opt{hidemin};
-		my $linemax = ($opt{hidemax} || @lines) - 1;
-		if ($linemin < 0) {
-			$linemin += @lines;
-			$linemax = @lines - $linemax;
-		}
+		my $linemin = $opt{hidemin} ? $opt{hidemin}->($#lines) : 0;
+		my $linemax = $opt{hidemax} ? $opt{hidemax}->($#lines, $linemin) : $#lines;
 		print varfmt('${sum+} of ', {
 			lines => $linemax - $linemin + 1,
 			sum => sum(0, grep {length} @values[$linemin .. $linemax]),
-		});
+		}) if $linemin <= $linemax;
 	}
 	if (@order) {
 		my $total = sum @order;
@@ -440,8 +448,8 @@ Options:
                            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
+  -L, --limit=[N|[-]START(-[END]|+N)]
+                           Select a range of lines to display
   -e, --log                Logarithmic (exponential) scale instead of linear
       --graph-format=CHAR  Glyph to repeat for the graph line
   -m, --markers=FORMAT     Statistical positions to indicate on bars
@@ -543,14 +551,16 @@ unless C<--length=0>.
 Prepend a dash (i.e. make negative) to enforce padding
 regardless of encountered contents.
 
-=item -L, --limit[=(<count> | -<last> | <start>-[<end>])]
+=item -L, --limit=[<count> | [-]<start>(-[<end>] | +<count>)]
 
-Stop output after a number of lines.
-A single value indicates the last line number (like C<head>),
+Select a range of lines to display.
+A single integer 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,
+A range consists of a starting line number followed by either
+a dash C<-> to an optional end, or plus sign C<+> with count.
+
+All hidden input is still counted and analyzed for statistics,
 but disregarded for padding and bar size.
 
 =item -e, --log