From fe7d6f864ad0d32f859587261760ca5747d22f91 Mon Sep 17 00:00:00 2001
From: Mike Swanson <mikeonthecomputer@gmail.com>
Date: Wed, 4 Sep 2019 14:08:34 -0700
Subject: [PATCH] dist/freedoom: use DOOMPORT envvar rather than PORT (breaking
 change)

PORT is too generic, especially if refering to TCP/UDP ports, and if
those are set, the freedoom script may not work properly.  DOOMPORT is
a reasonable alternative.
---
 dist/freedoom      | 10 +++++-----
 dist/freedoom.adoc | 18 ++++++++++--------
 2 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/dist/freedoom b/dist/freedoom
index aa84c169..08863923 100755
--- a/dist/freedoom
+++ b/dist/freedoom
@@ -12,7 +12,7 @@ PORTS="doom odamex crispy-doom prboom-plus eternity gzdoom chocolate-doom"
 
 if [ $# -gt 0 ]; then
     if [ "$1" = "-p" ]; then
-        PORT="$2"
+        DOOMPORT="$2"
         shift; shift
     elif [ "$1" = "--" ]; then
         shift
@@ -31,15 +31,15 @@ case "$(basename "$0")" in
         ;;
 esac
 
-if [ -z "$PORT" ] && [ -h "$HOME"/.doomport ]; then
+if [ -z "$DOOMPORT" ] && [ -h "$HOME"/.doomport ]; then
     if [ -f "$(readlink -f "$HOME"/.doomport)" ] \
         && [ -x "$(readlink -f "$HOME"/.doomport)" ]; then
-        PORT="$(readlink -f "$HOME"/.doomport)"
+        DOOMPORT="$(readlink -f "$HOME"/.doomport)"
     fi
 fi
 
-if [ "$PORT" ]; then
-    exec "$PORT" -iwad "$IWAD" "$@"
+if [ "$DOOMPORT" ]; then
+    exec "$DOOMPORT" -iwad "$IWAD" "$@"
 fi
 
 dirpath=$(eval echo "\${PATH}" 2>/dev/null | tr : ' ')
diff --git a/dist/freedoom.adoc b/dist/freedoom.adoc
index 580fc9b8..8d378244 100644
--- a/dist/freedoom.adoc
+++ b/dist/freedoom.adoc
@@ -8,7 +8,7 @@ freedoom - Automatically launch Freedoom with an engine
 
 SYNOPSIS
 --------
-*freedoom* [_-p_ _PORT_|_--_] [_ARGS_]
+*freedoom* [_-p_ _DOOMPORT_|_--_] [_ARGS_]
 
 DESCRIPTION
 -----------
@@ -21,13 +21,15 @@ active community since 1993.
 
 This command is a simple shell script to assist in running Freedoom,
 which is not a game engine itself nor part of any engine project, but
-playing Freedoom should remain simple.  Only accepted as the first
-argument, you may pass _-p PORT_, which will run Freedoom using the
-_PORT_ specified.  As an alternative, you may make a symbolic link
-named +$HOME/.doomport+ to your preferred port.  A port specified on
-the command line explicitly overrides +$HOME/.doomport+, whereas the
-existence of the symbolic link will override the detection of port
-based on a hard-coded list.
+playing Freedoom should remain simple.  The script tries to
+automatically select an engine based on a hard-coded list, but three
+overrides are available, in order of precedence: command-line
+argument, environment variable, and a +$HOME/.doomport+ symbolic link.
+Passing _-p DOOMPORT_ runs Freedoom using the _DOOMPORT_ specified.
+Setting the _DOOMPORT_ environment variable is similar, running the
+engine specified in the variable.  An additional permanent setting is
+via the +$HOME/.doomport+ symbolic link, which may point to an
+executable to run.
 
 Additional arguments passed to the program, or after specifying _--_
 as the first option, will be passed to the engine being called.  This