From 965f2376eca3e53f98eb26c53d8ff3c40c17d1de Mon Sep 17 00:00:00 2001
From: Case Duckworth
Date: Wed, 8 Mar 2023 10:56:34 -0600
Subject: Rewrite readc to work with ash

Also tested with dash --- does not work with bash
---
 vellum | 41 ++++++++++++++++++++++++++++-------------
 1 file changed, 28 insertions(+), 13 deletions(-)

diff --git a/vellum b/vellum
index b436b6c..aee12d5 100755
--- a/vellum
+++ b/vellum
@@ -1,7 +1,7 @@
 #!/bin/sh
 
-# https://unix.stackexchange.com/a/464963
 readc() { # arg: <variable-name>
+	# adapted from https://unix.stackexchange.com/a/464963
 	if [ -t 0 ]; then
 		# if stdin is a tty device, put it out of icanon, set min and
 		# time to sane value, but don't otherwise touch other input or
@@ -10,21 +10,36 @@ readc() { # arg: <variable-name>
 		saved_tty_settings=$(stty -g)
 		stty -icanon min 1 time 0
 	fi
-	eval "$1="
-	while
-		# read one byte, using a work around for the fact that command
-		# substitution strips the last character.
-		c=$(dd bs=1 count=1 2> /dev/null; echo .)
+
+	# Sanitize any variable that's passed in
+	case "$1" in
+		c) var=_c ;;
+		var) var=_var ;;
+		'') var=REPLY ;;
+		*) var="$1" ;;
+	esac
+
+	# Zero-out the variable
+	eval "$var="
+
+	# Read one full *character*, not *byte*
+	while :; do
+		c=$(dd bs=1 count=1 2>/dev/null; echo .)
 		c=${c%.}
 
-		# break out of the loop on empty input (eof) or if a full character
-		# has been accumulated in the output variable (using "wc -m" to count
-		# the number of characters).
-		[ -n "$c" ] &&
-			eval "$1=\${$1}"'$c
-	  [ "$(($(printf %s "${'"$1"'}" | wc -m)))" -eq 0 ]'; do
-		continue
+		# Break on EOF
+		test -n "$c" || break
+
+		eval "$var=\${$var}$c"
+
+		# Break when we have a full character (wc -m)
+		test "$(eval printf %s "\$$var" | wc -m)" -eq 0 || break
 	done
+
+	# Round-trip sanitized variables
+	test "x$var" = x_c && eval c="\$$var"
+	test "x$var" = x_var && eval var="\$$var"
+
 	if [ -t 0 ]; then
 		# restore settings saved earlier if stdin is a tty device.
 		stty "$saved_tty_settings"
-- 
cgit 1.4.1-21-gabe81