Nice logging for bash scripts

log.sh

#!/usr/bin/env bash

# Takes stdin as message and prepends timestamp and severity and writes it into the given log file
function log() {
    file=$1
    severity=$2
    while read text
    do
        LOGTIME=$(date "+%Y-%m-%d %H:%M:%S")
        touch $file
        if [ ! -f $file ]; then
            echo "ERROR! Cannot log to $file."
            exit 1
        fi
        echo "$LOGTIME :: $severity :: $text" >> $file
    done
}

# Echos the message into stderr
function error() {
    message=$1
    echo $message >&2
}

#################
# Usage:
# 
# # Include logging function
# . $(realpath "$(dirname $0)/includes/log.sh")
#
# # Define log file
# LOGFILE=/var/log/backup.log
#
# # Set up redirection:
# Pipe stdout into log function with $LOGFILE and "INFO" severity
# exec 1> >(log $LOGFILE "INFO")
# Pipe stderr into log function with $LOGFILE and "ERROR" severity
# exec 2> >(log $LOGFILE "ERROR")