watchc - Watch with colour

gistfile1.sh

#!/bin/bash
# Filename          watchc
# Description       execute a program periodically,showing fullscreen, colored output
# Author            Drew Fradette <http://www.github.com/drewfradette>
# Version           0.5
# Last Updated      2012-01-31
# Usage             watchc -n 5 ls -lah /tmp
# bash_version      4.2.10(1)-release
#######################################################
usage() {
    echo -e "Usage: watchc [-t] [-n <interval>] <command>\n"
    echo -e "-h\tPrint a summary of the available options."
    echo -e "-n\tSeconds to wait between updates. Defaults to 2 seconds."
    echo -e "-t\tTurns off showing the header."
}

# Initialize arguments to default values.
SHOW_TITLE=1
RECHECK=2

# Parse arguments
while getopts "htn:" OPTION; do
    case $OPTION in
        h) usage; exit;;
        t) SHOW_TITLE=0;;
        n) RECHECK=$OPTARG;;
        *) usage; exit;;
    esac
done

# Fetch the command to run
shift $((OPTIND-1))
COMMAND="$@"
if [ "$COMMAND" == "" ]; then
    echo -e "Error: You must specify a command\n"
    usage; exit 1;
fi

# The Business
while true; do
    TITLE=$(printf "Every %.1fs: %s" $RECHECK "$COMMAND")
    if [ $SHOW_TITLE -eq 1 ]; then
        PADDING=$(($(tput cols)-${#TITLE}))
        TITLE=$(printf "${TITLE}%${PADDING}s" "$(date)")
    fi
    clear; echo -e "\e[0;33m$TITLE\e[0m";
    $COMMAND; sleep $RECHECK;
done