feat: Add PID file

docs/boring-backup.1.rst

@@ -15,7 +15,7 @@ backup files and databases.
 Синопсис
 --------
 
-``boring-backup`` [-cvlhV] FILES..
+``boring-backup`` [-cvlphV] FILES..
 
 Описание
 --------
@@ -28,6 +28,7 @@ boring-backup - это расширяемая утилита для резерв
 -c, --config    config file.
 -v, --verbose   verbose output.
 -l, --log-file  log file.
+-p, --pid-file  PID file.
 -h, --help      print this help messagea and exit.
 -V, --version   print version and exit.
 

src/boring-backup

@@ -21,10 +21,12 @@ __config=
 __verbose=
 __log_file='./log.txt'
 __log_date_fmt='%d/%b/%Y:%H:%M:%S %z'
+__pid_file='/tmp/boring-backup.pid'
 __tar_options='-acf'
 __tar_exclude=
 __name_date_fmt='_%Y%m%d-%H%M'
 __compression='gzip'
+
 LIBRARY="${LIBRARY:-./lib}"
 
 # Source library
@@ -39,12 +41,13 @@ print_help() {
     cat <<- EOF
 Backup files and databases.
 
-Usage: $0 [-cvlhV] FILES..
+Usage: $0 [-cvlphV] FILES..
 
 Options:
     -c, --config    config file.
     -v, --verbose   verbose output.
-    -l, --log-file  log file.
+    -l, --log-file  log file [default: $__log_file]
+    -p, --pid-file  PID file [default: $__pid_file]
     -h, --help      print this help messagea and exit.
     -V, --version   print version and exit.
 
@@ -101,6 +104,7 @@ while (( "$#" )); do
         -c|--config|--config=*) optval "$1" "$2"; __config="$val"; shift "$sft";;
         -v|--verbose) __verbose=1; shift;;
         -l|--log-file|--log-file=*) optval "$1" "$2"; __log_file="$val"; shift "$sft";;
+        -p|--pid-file|--pid-file=*) optval "$1" "$2"; __pid_file="$val"; shift "$sft";;
         -h|--help) print_help; exit 1;;
         -V|--version) echo "$__version"; exit 0;;
         -*) echo "Error: Unknown option: $1" >&2; exit 1;;
@@ -112,19 +116,32 @@ done
 # * Do backups                                               #
 # ---------------------------------------------------------- #
 
+log "Backup STARTED"
+
+# Check PID file
+if [ -e $__pid_file ]; then
+    if [ -z "$(ps ax -o pid | grep "$(cat $__pid_file)")" ]; then
+        err "Process $(cat $__pid_file) died."
+        rm $__pid_file
+    else
+        err -e "Process $(cat $__pid_file) still running.";
+    fi
+fi
+
+# Touch PID file
+echo $$ > $__pid_file
+
 # Scripts counter.
 __count=${#__args[@]}    # count
 __iter=1                 # iterator
 
 # Startup log.
 date +'Start: %d %b %Y %T %z'
-log "Backup STARTED"
 log -p "Library path: $LIBRARY"
 log -p "Log file: $__log_file"
 log -p "Configuration file: $([ "$__config" ] || echo not specified && echo "$__config")"
 log "Scripts to process (${__count}): ${__args[@]}"
 
-
 for script in "${__args[@]}"; do
     # Initialise variables
     __user_script="$script"
@@ -176,3 +193,6 @@ done
 
 log "Backup FINISHED"
 echo -e "\nBackup [Done]"
+
+# Remove PID file
+rm $__pid_file