From 326b106fe21934257b110dc01fccc9a8a9672f4c Mon Sep 17 00:00:00 2001
From: Matthias Kruk <m@m10k.eu>
Date: Mon, 22 Mar 2021 09:36:25 +0900
Subject: [PATCH] include/log: Add logging facilities

This commit adds the log module which can be adopted by scripts to log
messages to log files that are stored in TOOLBOX_HOME. The module also
provides convenience functions for highlighting output and printing
stack traces.
---
 include/log.sh | 134 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 134 insertions(+)
 create mode 100644 include/log.sh

diff --git a/include/log.sh b/include/log.sh
new file mode 100644
index 0000000..d4e3760
--- /dev/null
+++ b/include/log.sh
@@ -0,0 +1,134 @@
+#!/bin/bash
+
+__init() {
+	local script_name
+	local timestamp
+
+	if ! script_name=$(basename "$BASH_ARGV0"); then
+		echo "Could not determine script name" 1>&2
+		return 1
+	fi
+
+	if ! timestamp=$(date +"%Y-%m-%d.%H:%M"); then
+		echo "Could not make timestamp for the log name" 1>&2
+		return 1
+	fi
+
+	declare -xgri __log_debug=3
+	declare -xgri __log_info=2
+	declare -xgri __log_warning=1
+	declare -xgri __log_error=0
+
+	declare -xgi __log_verbosity="$__log_warning"
+	declare -xgr __log_path="$TOOLBOX_HOME/log"
+	declare -xgr __log_file="$__log_path/$timestamp.$script_name.$$.log"
+
+	if ! mkdir -p "$__log_path"; then
+		return 1
+	fi
+
+	return 0
+}
+
+log_set_verbosity() {
+	local verb
+
+	verb="$1"
+
+	if (( verb < __log_error )); then
+		verb="$__log_error"
+	elif (( verb > __log_debug )); then
+	        verb="$__log_debug"
+	fi
+
+	__log_verbosity="$verb"
+
+	return 0
+}
+
+log_get_verbosity() {
+	echo "$__log_verbosity"
+}
+
+log_write() {
+	local level
+	local prefix
+	local line
+
+	level="$1"
+	prefix="$2"
+
+	if (( __log_verbosity < level )); then
+		return 0
+	fi
+
+	if (( $# > 2 )); then
+		for line in "${@:3}"; do
+			if ! date +"%F %T %z $prefix $line" >> "$__log_file"; then
+				echo "Could not write to $__log_file" 1>&2
+				return 1
+			fi
+		done
+	else
+		while read -r line; do
+			log_write "$level" "$prefix" "$line"
+		done
+	fi
+
+	return 0
+}
+
+log_stacktrace() {
+	local i
+	local indent
+
+	echo "Stacktrace:"
+	indent="  "
+
+	for (( i = "${#FUNCNAME[@]}"; i > 1; )); do
+		((i--))
+		echo "$indent${BASH_SOURCE[$i]}:${BASH_LINENO[$i]} ${FUNCNAME[$i]}"
+		ident+=" "
+	done
+
+	return 0
+}
+
+log_highlight() {
+	local tag
+
+	tag="$1"
+
+	echo "===== BEGIN $tag ====="
+	if (( $# > 1 )); then
+		local arg
+
+		for arg in "${@:2}"; do
+			echo "$arg"
+		done
+	else
+		cat /dev/stdin
+	fi
+	echo "===== END $tag ====="
+}
+
+log_debug() {
+	local dbgtag
+	local line
+
+	dbgtag="${BASH_SOURCE[1]}:${BASH_LINENO[1]} ${FUNCNAME[1]}:"
+
+	log_write "$__log_debug" "[DBG] $dbgtag" "$@"
+}
+
+log_info() {
+	log_write "$__log_info" "[INF]" "$@"
+}
+
+log_warn() {
+	log_write "$__log_warning" "[WRN]" "$@"
+}
+
+log_error() {
+	log_write "$__log_error" "[ERR]" "$@"
+}
-- 
2.47.3