From 94685827b3286df2f0d8dfb15e0be9df07998bfa Mon Sep 17 00:00:00 2001
From: Christoph <ckubu@oopen.de>
Date: Sun, 24 Oct 2021 13:01:55 +0200
Subject: [PATCH] Add script 'read_env_from_file.sh'

---
 snippets/read_env_from_file.sh | 107 +++++++++++++++++++++++++++++++++
 1 file changed, 107 insertions(+)
 create mode 100755 snippets/read_env_from_file.sh

diff --git a/snippets/read_env_from_file.sh b/snippets/read_env_from_file.sh
new file mode 100755
index 0000000..9d21af3
--- /dev/null
+++ b/snippets/read_env_from_file.sh
@@ -0,0 +1,107 @@
+#!/usr/bin/env bash
+
+clear
+
+temp_file=$(mktemp)
+
+echo -e "** Testfile '$temp_file' (will be removed at end of script) **"
+cat <<EOF > $temp_file
+#! /usr/bin/env bash
+#     Written by Miquel van Smoorenburg <miquels@cistron.nl>.
+# ...
+
+INIT_SCRIPT=/etc/init.d/test-service
+
+### BEGIN INIT INFO
+# Provides: postfwd
+# ...
+### END INIT INFO
+
+PATH=/sbin:/bin:/usr/sbin:/usr/bin
+NAME=postfwd
+DAEMON=/usr/sbin/\${NAME}
+PIDFILE=/var/run/\$NAME.pid
+DESC=postfwd
+EOF
+
+echo ""
+echo -e "\033[33m"
+cat $temp_file
+echo -e "\033[m"
+echo ""
+echo ""
+
+trim() {
+    local var="$*"
+    var="${var#"${var%%[![:space:]]*}"}"   # remove leading whitespace characters
+    var="${var%"${var##*[![:space:]]}"}"   # remove trailing whitespace characters
+    echo -n "$var"
+}
+
+trim_double_quotes() {
+    local var="$*"
+    var="${var#"${var%%[!\"]*}"}"   # remove leading whitespace characters
+    var="${var%"${var##*[!\"]}"}"   # remove trailing whitespace characters
+    echo -n "$var"
+}
+
+read_env_from_file() {
+
+   _file="$*"
+
+   while read _ENV _REST ; do
+
+      _ENV="$(trim $_ENV)"
+
+      if [[ "$_ENV" =~ .{2,}=.+ ]]; then
+         _key="${_ENV%=*}"
+         _val="${_ENV##*=}"
+
+         [[ "$_key" = "PATH" ]] && continue
+
+
+         # - Remove leading / trailling double quotes
+         # -    _val="${_val%\"}"
+         # -    _val="${_val#\"}"
+         # -
+         _val="$(trim_double_quotes $_val)"
+
+         if [[ -n "$(trim $_key)" ]] && [[ -n "$(trim $_val)" ]] ; then
+            export $_ENV
+         fi
+      fi
+
+   done < "$_file"
+
+}
+
+
+echo -e "\t\033[32m---\033[m"
+echo -e "\tRead environment variables from Testfile \033[1m$temp_file\033[m:"
+echo -e "\t\033[32m---\033[m"
+read_env_from_file $temp_file
+
+echo ""
+echo -e "\tINIT_SCRIPT: \033[32m$INIT_SCRIPT\033[m"
+echo ""
+echo -e "\t# PATH Variable should be ommitted. So your real env PATH should be printed out"
+echo -e "\t#"
+echo -e "\tPATH:        $PATH"
+echo ""
+echo -e "\tNAME:        \033[32m$NAME\033[m"
+echo -e "\tDDAEMON:     \033[32m$DAEMON\033[m"
+echo -e "\tPIDFILE:     \033[32m$PIDFILE\033[m"
+echo -e "\tDESC:        \033[32m$DESC\033[m"
+echo ""
+
+echo ""
+echo ""
+echo -e "\t# Maybe you have to evaluate some variable.."
+echo -e "\t#"
+echo -e "\tDDAEMON:     \033[32m$(eval echo $DAEMON)\033[m"
+echo -e "\tPIDFILE:     \033[32m$(eval echo $PIDFILE)\033[m"
+echo ""
+
+
+rm -f $temp_file
+exit 0