source general_utils only once

general_utils

@@ -3,47 +3,61 @@
 
 source ./log_helpers
 
-exec_process_substitution () {
-    local func="${FUNCNAME[0]}"
-    log_debug "$func:${LINENO} exec-ing [$*]"
+if [ "${general_utils_sourced:-1}" = "1" ]; then    # include only once
+    readonly general_utils_sourced=${BASH_SOURCE[0]}
 
-    exec {fd}< <(eval "$@")
+    exec_process_substitution () {
+        local func="${FUNCNAME[0]}"
+        log_debug "$func:${LINENO} exec-ing [$*]"
 
-    local __result_code=$?
-    local ps_pid=$!  # remember pid of process substitution
+        exec {fd}< <(eval "$@")
 
-    local __result=""
-    while read __tmp <&$fd; do
-        if ! [ -z "$__tmp" ]; then
-            __result="${__result}$__tmp"
-        fi
-    done
+        local __result_code=$?
+        local ps_pid=$!  # remember pid of process substitution
+
+        local __result=""
+        while read __tmp <&$fd; do
+            if ! [ -z "$__tmp" ]; then
+                __result="${__result}$__tmp"
+            fi
+        done
         
-    exec {fd}>&-    # close fd (i.e. process substitution)
-    wait $ps_pid    # wait for the subshell to finish
+        exec {fd}>&-    # close fd (i.e. process substitution)
+        wait $ps_pid    # wait for the subshell to finish
 
-    __result=${__result//[$'\r\n\t']/ } # remove \r\n\t from __result
+        __result=${__result//[$'\r\n\t']/ } # remove \r\n\t from __result
 
-    log_debug "$func:${LINENO} result=$__result"
-    printf '%s' "$__result"
-    return $__result_code
-}
+        log_debug "$func:${LINENO} result=$__result"
+        printf '%s' "$__result"
+        return $__result_code
+    }
 
-usage () {
-    echo "Usage: $PROGRAM [--file config] [--?] [--help] [--version] [--dbg]" 
-    # UpdateController.conf"
-}
+    usage () {
+        echo "Usage: $PROGRAM [--file config] [--?] [--help] [--version] [--dbg]" 
+        # UpdateController.conf"
+    }
 
-usage_and_exit () {
-    usage
-    exit $1
-}
+    usage_and_exit () {
+        usage
+        exit $1
+    }
 
-version () {
-    echo "$PROGRAM version $VERSION"
-}
+    version () {
+        echo "$PROGRAM version $VERSION"
+    }
 
-error () {
-    echo "$@" 1>&2
-    usage_and_exit 1
-}
+    error () {
+        echo "$@" 1>&2
+        usage_and_exit 1
+    }
+
+    alert () {
+        # usage: alert <$?> <object>
+        if [ "$1" ne 0 ]; then
+            echo "WARNING: $2 did not complete successfully." >&2
+            exit 1
+        else
+            echo "INFO: $2 completed successfully" >&2
+        fi
+    }
+fi