Bash CLI to watch a file and execute commands on file update

checkmod.md

checkmod

Bash CLI to watch a file and execute commands on file update

Installation

• Download the checkmod.sh file
• Copy the checkmod.sh file and give permissions to execute

$ cp checkmod.sh /usr/bin/checkmod
$ chmod +x /usr/bin/checkmod

Example Usage

$ checkmod main.cpp "g++ main.cpp && eval ./a.out"

Keep watching ;)

checkmod.sh

#!/bin/bash

TIMER=0.1
FILE=$1
CMD=$2

if [ ! -f "$FILE" ]; then
   echo "File not found! Exiting watch mode."
   exit
fi

LAST_TIME=`stat -c "%Y" $FILE`

declare -a LOADER=("|" "/" "—" "\\")

ok_bye () {
   echo -ne "\r\033[0KShutting down watch! Bye.\n"
   exit
}

check_and_eval () {
   a=`stat -c "%Y" $FILE`
   if [[ ! ("$a" -eq "$LAST_TIME") ]]; then
        let LAST_TIME="$a"
        b=`date -r $FILE`
        echo -ne "\r\033[0K[UPDATE] $b\n"
        eval "$CMD"
        echo ""
   fi
}

run_infy () {
   index=0

   while `true`
   do
        if [ "$index" -eq 3 ]; then
           index=0
        else
           let index++
        fi
        echo -ne \\r ${LOADER[$index]} "Watching $FILE for changes\033[0K"
        check_and_eval
        sleep $TIMER
   done
}

trap ok_bye SIGINT SIGTERM
run_infy