minimum limit to override start line number

[barcat.git] / barcat

diff --git a/barcat b/barcat
index 1a70964c320bc2b66fc0abb8ca09112a0e675656..c4244d4e61d5e99d4c80d6432387782f27d4296d 100755 (executable)
--- a/barcat
+++ b/barcat
@@ -6,7 +6,7 @@ use List::Util qw( min max sum );
 use open qw( :std :utf8 );
 use experimental qw( lexical_subs );
 
-our $VERSION = '1.02';
+our $VERSION = '1.03';
 
 use Getopt::Long '2.33', qw( :config gnu_getopt );
 sub podexit {
@@ -29,6 +29,10 @@ GetOptions(\%opt,
                $opt{trim} = $optval;
        },
        'value-length=i',
+       'hidemin=i',
+       'hidemax|limit|L=i' => sub {
+               $opt{$_[1] < 0 ? 'hidemin' : 'hidemax'} = abs $_[1];
+       },
        'markers|m=s',
        'unmodified|u!',
        'width|w=i',
@@ -75,15 +79,16 @@ $SIG{INT} = 'DEFAULT';
 
 sub show_lines {
 
-state $nr = 0;
+state $nr = $opt{hidemin} ? $opt{hidemin} - 1 : 0;
 @lines and @lines > $nr or return;
 
 my @order  = sort { $b <=> $a } grep { length } @values;
-my $maxval = $order[0];
+my $maxval = $opt{hidemax} ? max @values[0 .. $opt{hidemax} - 1] : $order[0];
 my $minval = min $order[-1], 0;
 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 .. $#lines;  # left padding
+       max map { length $values[$_] && length $lines[$_] }
+               0 .. min $#lines, $opt{hidemax} || ();  # left padding
 my $size   = ($maxval - $minval) &&
        ($opt{width} - $lenval - $len) / ($maxval - $minval);  # bar multiplication
 
@@ -112,6 +117,7 @@ if ($opt{markers} // 1 and $size > 0) {
 }
 
 while ($nr <= $#lines) {
+       $nr >= $opt{hidemax} and last if $opt{hidemax};
        my $val = $values[$nr];
        if (length $val) {
                my $color = !$opt{color} ? 0 :
@@ -125,6 +131,7 @@ while ($nr <= $#lines) {
        printf '%-*s', $len + length($val), $line;
        print $barmark[$_] // '-' for 1 .. $size && (($values[$nr] || 0) - $minval) * $size + .5;
        say '';
+
        $nr++;
 }
 
@@ -135,11 +142,11 @@ __END__
 
 =head1 NAME
 
-graph - append bar chart to input numbers
+barcat - graph to visualize input values
 
 =head1 SYNOPSIS
 
-B<graph> [<options>] [<input>]
+B<barcat> [<options>] [<input>]
 
 =head1 DESCRIPTION
 
@@ -183,6 +190,12 @@ unless C<--length=0>.
 Prepend a dash (i.e. make negative) to enforce padding
 regardless of encountered contents.
 
+=item -L, --limit=[-]<count>
+
+Stop output after a number of lines.
+All input is still counted and analyzed for statistics,
+but disregarded for padding and bar size.
+
 =item -m, --markers=
 
 Statistical positions to indicate on bars.
@@ -236,64 +249,64 @@ Appended graphics will extend to fill up the entire screen.
 
 Commonly used after counting, such as users on the current server:
 
-    users | sed 's/ /\n/g' | sort | uniq -c | graph
+    users | sed 's/ /\n/g' | sort | uniq -c | barcat
 
 Letter frequencies in text files:
 
     cat /usr/share/games/fortunes/*.u8 |
     perl -CO -nE 'say for grep length, split /\PL*/, uc' |
-    sort | uniq -c | graph
+    sort | uniq -c | barcat
 
 Memory usage of user processes:
 
-    ps xo %mem,pid,cmd | graph -l40
+    ps xo %mem,pid,cmd | barcat -l40
 
 Sizes (in megabytes) of all root files and directories:
 
-    du -d0 -m * | graph
+    du -d0 -m * | barcat
 
 Number of HTTP requests per day:
 
-    cat log/access.log | cut -d\  -f4 | cut -d: -f1 | uniq -c | graph
+    cat log/access.log | cut -d\  -f4 | cut -d: -f1 | uniq -c | barcat
 
 Any kind of database query with leading counts:
 
     echo 'SELECT count(*),schemaname FROM pg_tables GROUP BY 2' |
-    psql -t | graph -u
+    psql -t | barcat -u
 
 Exchange rate USD/EUR history from CSV download provided by ECB:
 
     curl https://sdw.ecb.europa.eu/export.do \
          -Gd 'node=SEARCHRESULTS&q=EXR.D.USD.EUR.SP00.A&exportType=csv' |
-    grep '^[12]' | graph -f',\K' --value-length=7
+    grep '^[12]' | barcat -f',\K' --value-length=7
 
 Total population history from the World Bank dataset (XML):
 
     curl http://api.worldbank.org/v2/country/1W/indicator/SP.POP.TOTL |
     xmllint --xpath '//*[local-name()="date" or local-name()="value"]' - |
-    sed -r 's,</wb:value>,\n,g; s,(<[^>]+>)+, ,g' | graph -f1
+    sed -r 's,</wb:value>,\n,g; s,(<[^>]+>)+, ,g' | barcat -f1
 
 Movies per year from prepared JSON data:
 
     curl https://github.com/prust/wikipedia-movie-data/raw/master/movies.json |
-    jq '.[].year' | uniq -c | graph
+    jq '.[].year' | uniq -c | barcat
 
 Pokémon height comparison:
 
        curl https://github.com/Biuni/PokemonGO-Pokedex/raw/master/pokedex.json |
-       jq -r '.pokemon[] | [.height,.num,.name] | join(" ")' | graph
+       jq -r '.pokemon[] | [.height,.num,.name] | join(" ")' | barcat
 
 Git statistics, such commit count by year:
 
-    git log --pretty=%ci | cut -b-4 | uniq -c | graph
+    git log --pretty=%ci | cut -b-4 | uniq -c | barcat
 
 Or the most frequent authors:
 
-    git shortlog -sn | graph | head -3
+    git shortlog -sn | barcat -L3
 
 Latency history:
 
-    ping google.com | graph -f'time=\K' -t
+    ping google.com | barcat -f'time=\K' -t
 
 =head1 AUTHOR