bash: add message lib example

scripts/message_bash/include.sh

@@ -0,0 +1,18 @@
+#!/usr/bin/env bash
+
+myfunct() {
+  local a=10
+  debug "my a variable is $a"
+  msg "value of 'a' squared: $(( a * a ))"
+}
+
+check_file() {
+  if [ ! -f "monfichier.txt" ]
+  then
+    display_error "File monfichier.txt not found"
+  fi
+}
+
+display_error() {
+  error "$*"
+}

scripts/message_bash/message.sh

@@ -0,0 +1,55 @@
+#!/usr/bin/env bash
+
+DATE_FMT="+%s"
+
+msg() {
+  local message="$*"
+  [ -z "$message" ] && return
+  if [ -t 1 ]
+  then
+    printf "%b\n" "$message"
+  else
+    log "$message"
+  fi
+}
+
+log() {
+   local message="${*-}"
+   [ -z "$message" ] && return
+   printf "%s %b\n" "$(date $DATE_FMT)" "$message"
+}
+
+debug() {
+  local message="$*"
+  [[ -z $DEBUG || $DEBUG -ne 1 ]] && return 
+  [ -z "$message" ] && return
+  message="DEBUG [${BASH_SOURCE[1]}:${FUNCNAME[1]}]: $message"
+  if [ -t 2 ]
+  then
+    >&2 msg "\e[34m$message\e[0m"
+  else
+    >&2 log "$message"
+  fi
+}
+
+error() {
+  local message="$*"
+  [ -z "$message" ] && return 
+  message="ERROR: $message"
+  if [[ -n $DEBUG && $DEBUG -eq 1 ]]
+  then
+    message="$message\n\tstack trace:\n"
+    for (( i=1; i<${#FUNCNAME[@]}; i++ ))
+    do
+      message="${message}\t  source:${BASH_SOURCE[i]}"
+      message="${message} function:${FUNCNAME[$i]}"
+      message="${message} line:${BASH_LINENO[$i-1]}\n" 
+    done
+  fi
+  if [ -t 2 ]
+  then
+    >&2 msg "\e[31m$message\e[0m"
+  else
+    >&2 log "$message"
+  fi
+}

scripts/message_bash/test.sh

@@ -0,0 +1,9 @@
+#!/usr/bin/env bash
+source message.sh || { >&2 printf "Can't load message.sh"; exit 1; }
+source include.sh || { >&2 printf "Can't load include.sh"; exit 1; }
+myfunct
+check_file
+debug "We will display a message"
+msg "Test Message"
+error "This is a simple error message"
+exit 0