Cron Limiter - initial

README.md

@@ -1,3 +1,8 @@
 # Code Snippets
 Repository of random code snippets and examples.
 
+## Contents
+
+- cron-limiter - limits cron jobs from running too often
+- example-tray-icon - showing desktop notifications
+

cron-limiter/README.md

@@ -0,0 +1,28 @@
+# Crolim - Cron Limiter
+
+This utility allows you to schedule frequent cron jobs that don't actually do anything until some criteria is met (e.g. date changed).
+
+Example use case: your phone is suspended throughout the day and you want to run a daily cron job without waking the phone needlessly.
+
+## Usage
+
+Mostly usable as a "prefix" for your cron jobs.
+
+## Basic
+
+Run a podcast getter daily
+```
+crolim podget
+```
+
+## Advanced
+
+Run a podcast getter daily (explicit version of the basic example):
+```
+crolim --memory-file=$HOME/.config/crolim/memory-podcast --status-command="date +%D" podget
+```
+
+## Install
+
+Copy it to `/usr/local/bin/` with execute permissions.
+

cron-limiter/crolim

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+#!/bin/bash
+
+VERBOSE=0
+CONFIG_DIR=$HOME/.config/crolim
+MEMORY_FILE=${CONFIG_DIR}/memory
+STATUS_COMMAND="date +%D"
+
+function usage() {
+	echo "Usage: $0 [OPTIONS] COMMAND"
+	echo "       $0 -h"
+	echo ""
+	echo "  -h ... show help"
+	echo ""
+	echo " OPTIONS"
+	echo "  -m --memory-file    ... location to store previous status value"
+	echo "  -s --status-command ... command to execute to get the current status"
+    echo "  -v --verbose        ... verbose mode"
+	echo " COMMAND ... command to limit until memory and status are the same"
+}
+
+# read the options
+TEMP=`getopt -o m:s:hv --long memory-file:,status-command:,help,verbose -- "$@"`
+eval set -- "$TEMP"
+
+while true ; do
+	case "$1" in
+		-h | --help) usage; exit 0
+			;;
+        -v | --verbose) VERBOSE=1 ; shift
+            ;;
+        -m | --memory-file)
+            MEMORY_FILE=$2 ; shift 2
+            ;;
+        -s | --status-command)
+            STATUS_COMMAND=$2 ; shift 2
+            ;;
+        --) shift ; break ;;
+        *) echo "Internal error!" ; exit 1 ;;
+    esac
+done
+
+# check limiting condition
+#mkdir -p `dirname $MEMORY_FILE`
+STATUS_NOW=`eval $STATUS_COMMAND`
+STATUS_MEMORY=""
+if [[ -f $MEMORY_FILE ]]; then
+    STATUS_MEMORY=`cat $MEMORY_FILE`
+fi
+if [[ "$STATUS_NOW" == "$STATUS_MEMORY" ]]; then
+    [[ $VERBOSE == 1 ]] && echo "Limiting, status is the same: ${STATUS_NOW}"
+    exit 0
+else
+    [[ $VERBOSE == 1 ]] && echo "Status changed from '${STATUS_MEMORY}' to '${STATUS_NOW}'"
+    echo ${STATUS_NOW} > $MEMORY_FILE || { echo "Cannot update memory file: $MEMORY_FILE" ; exit 1 ; }
+fi
+
+# run the command!
+eval $@
+