libremakepkg: when prefixing output with ' | ', do better than sed.

There are two downsizes to using sed; it line-buffers, and (the existing
pattern) doesn't handle '\r'.

So, now I've included a Perl helper program to do a better job.

I'd originally written it in C, and while that version was faster (the Perl
version stutters occasionally), it required recompilation for different
architectures.  I could have gotten around that with tcc, but I didn't want
to add any dependencies.  Which is why I settled on Perl.  It's part of
group=(base), and it is required by packages in group=(base-devel), so I
can count on it always being there.

It doesn't handle every movement character, just '\n' and '\r', but that's
enough for curl and pacman.

1 files changed, 33 insertions, 0 deletions

diff --git a/src/chroot-tools/indent b/src/chroot-tools/indent
new file mode 100755
index 0000000..5a7f654
--- /dev/null
+++ b/src/chroot-tools/indent
@@ -0,0 +1,33 @@
+#!/usr/bin/env perl
+use warnings;
+use strict;
+use constant BUFFER_SIZE => 40;
+binmode(STDIN);
+binmode(STDOUT);
+
+exit(1) if ($#ARGV != 0);
+my $indent = $ARGV[0];
+
+my $print_indent = 1;
+my $buffer;
+my $size;
+my $c;
+while (1) {
+	$size = sysread(STDIN, $buffer, BUFFER_SIZE);
+	last if ($size < 1);
+	for (0..$size-1) {
+		$c = substr($buffer, $_, 1);
+		if ($c eq "\n") {
+			syswrite(STDOUT, $indent) if ($print_indent);
+			syswrite(STDOUT, $c, 1);
+			$print_indent = 1;
+		} elsif ($c eq "\r") {
+			syswrite(STDOUT, $c, 1);
+			$print_indent = 1;
+		} else {
+			syswrite(STDOUT, $indent) if ($print_indent);
+			syswrite(STDOUT, $c, 1);
+			$print_indent = 0;
+		}
+	}
+}