Port edda(1) to POSIX sh

Losing the option-passing; could perhaps add this in again by
specifically supporting POSIX-specific options for ed(1)

1 files changed, 15 insertions, 26 deletions

diff --git a/bin/edda b/bin/edda
index 26d78b94..b06a50c8 100755
--- a/bin/edda
+++ b/bin/edda
@@ -1,44 +1,33 @@
-#!/usr/bin/env bash
+#!/bin/sh
 # Run ed(1) over multiple files, duplicating stdin.
 
-# Give up completely if no BASH_VERSINFO (<2.0)
-[ -n "$BASH_VERSINFO" ] || exit
-
-# Parse options out, give help if necessary
-declare -a opts
-for arg ; do
-    case $arg in
-        --)
-            shift
-            break
-            ;;
-        -*)
-            shift
-            opts[${#opts[@]}]=$arg
-            ;;
-    esac
-done
-
 # Need at least one file after options are parsed out
-if ! (($#)) ; then
+if [ "$#" -eq 0 ] ; then
     printf >&2 'edda: Need at least one file\n'
     exit 2
 fi
 
-# Create a temporary directory with name in $td, and a trap to remove it when
-# the script exits
+# Create a temporary directory with name in $td, and handle POSIX-ish traps to
+# remove it when the script exits.
 td=
 cleanup() {
-    [[ -n "$td" ]] && rm -fr -- "$td"
+    [ -n "$td" ] && rm -fr -- "$td"
+    if [ "$1" != EXIT ] ; then
+        trap - "$1"
+        kill "-$1" "$$"
+    fi
 }
-trap cleanup EXIT
+for sig in EXIT HUP INT TERM ; do
+    # shellcheck disable=SC2064
+    trap "cleanup $sig" "$sig"
+done
 td=$(mktd "$self") || exit
 
 # Duplicate stdin into a file
 script=$td/script
 cat >"$script" || exit
 
-# Run ed(1) over each file with the options and stdin given
+# Run ed(1) over each file with the stdin given
 for file ; do
-    ed "${opts[@]}" -- "$file" <"$script"
+    ed -- "$file" <"$script"
 done