1 files changed, 76 insertions, 0 deletions
diff --git a/etc/wpdf b/etc/wpdf
new file mode 100755
index 0000000..94e5029
--- /dev/null
+++ b/etc/wpdf
@@ -0,0 +1,76 @@
+#!/usr/bin/perl
+
+# wpdf -- view, watch and remake pdf based on Makefile
+
+use strict;
+use warnings;
+
+my $alive;        # number of children alive
+my %deptarget;    # dependency => target
+my $parent = $$;  # pid of parent
+
+$SIG{USR1} = sub { kill 'HUP', 0 if not --$alive };
+$SIG{HUP} = sub { exit 0 };
+
+# collect dependencies for given files
+for my $target (@ARGV) {
+	# if pdf, collect from Makefile
+	if ($target =~ /\.pdf$/) {
+		(my $basename = $target) =~ s/\.pdf$//;
+		open my $f, '<', 'Makefile'
+			or die "could not open Makefile: $!\n";
+		while (<$f>) {
+			# explicit
+			if (/^\Q$target\E:\s*(.*)/) {
+				$deptarget{$_} = $target for split /\s/, $1;
+				last;
+			}
+			# implicit
+			if (/^\.([^ .]+)\.pdf\s*:\s*(.*)/) {
+				$deptarget{"$basename.$1"} = $target;
+				$deptarget{$_} = $target for split /\s/, $2;
+				last;
+			}
+		}
+		close $f;
+	}
+
+	# if not pdf, assume target is actually source file and collect from it
+	# (with build(1) syntax)
+	else {
+		my $i = 0;
+		my $source = $target;
+		$target =~ s,\.[^./]*$,,; $target .= '.pdf';
+		$deptarget{$source} = $target;
+
+		open my $f, '<', $source;
+		while (<$f>) {
+			last if ++$i > 20;
+			if (/\s% (.*)/) {
+				$deptarget{$_} = $target for split /\s/, $1;
+				last;
+			}
+		}
+		close $f;
+	}
+
+	if (fork == 0) {
+		system 'xpdf', '-remote', "wpdf-$target", $target;
+		kill 'USR1', $parent;
+		exit;
+	}
+	$alive++;
+}
+
+die "no dependencies found\n" if not keys %deptarget;
+
+# make pdf on demand
+open my $p, '-|', 'watch', keys %deptarget
+	or die "could not start watch: $!\n";
+while (<$p>) {
+	chomp;
+	system('make', "$deptarget{$_}") == 0
+		&& system('xpdf', '-remote', "wpdf-$deptarget{$_}", '-reload');
+}
+close $p;
+exit($? != 0);