From 992b652af325ad34b616ffc169016fbe7f659c96 Mon Sep 17 00:00:00 2001
From: Kirill Smelkov <kirr@landau.phys.spbu.ru>
Date: Wed, 21 Jan 2009 23:18:42 +0300
Subject: [PATCH] Implement setup_pager just like in git

setup_pager() spawns a pager process and redirect the rest of our output
to it.

This will be needed to fix `tg patch` output in the next commit.

Signed-off-by: Kirill Smelkov <kirr@landau.phys.spbu.ru>
---
 tg.sh | 38 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/tg.sh b/tg.sh
index 8c23d26..b64fc3a 100644
--- a/tg.sh
+++ b/tg.sh
@@ -243,6 +243,44 @@ do_help()
 	fi
 }
 
+## Pager stuff
+
+# isatty FD
+isatty()
+{
+	test -t $1
+}
+
+# setup_pager
+# Spawn pager process and redirect the rest of our output to it
+setup_pager()
+{
+	isatty 1 || return 0
+
+	# TG_PAGER = GIT_PAGER | PAGER | less
+	# NOTE: GIT_PAGER='' is significant
+	TG_PAGER=${GIT_PAGER-${PAGER-less}}
+
+	[ -z "$TG_PAGER"  -o  "$TG_PAGER" = "cat" ]  && return 0
+
+
+	# now spawn pager
+	export LESS=${LESS:-FRSX}	# as in pager.c:pager_preexec()
+
+	_pager_fifo_dir="$(mktemp -t -d tg-pager-fifo.XXXXXX)"
+	_pager_fifo="$_pager_fifo_dir/0"
+	mkfifo -m 600 "$_pager_fifo"
+
+	"$TG_PAGER" < "$_pager_fifo" &
+	exec > "$_pager_fifo"		# dup2(pager_fifo.in, 1)
+
+	# this is needed so e.g. `git diff` will still colorize it's output if
+	# requested in ~/.gitconfig with color.diff=auto
+	export GIT_PAGER_IN_USE=1
+
+	# atexit(close(1); wait pager)
+	trap "exec >&-; rm \"$_pager_fifo\"; rmdir \"$_pager_fifo_dir\"; wait" EXIT
+}
 
 ## Startup
 
-- 
2.30.2