Shell Programming and Scripting

for ip in 192.168.1.{1..10}; do  # for loop and the {} operator
    ping -c 1 -t 1 192.168.1.1 > /dev/null 2> /dev/null  # ping and discard output
    if [ $? -eq 0 ]; then  # check the exit code
        echo "${ip} is up" # display the output
    else
        echo "${ip} is down"
    fi
done

IP_PRE=192.168.1
[ -z "$1" ] && echo "Usage: ${0##*/} 15 30-37 42 .."

for num in "${@}";do
# Parse all the arguments
	if [ "-" = "$(echo $num|tr -d [[:digit:]])" ]
	then	# Its a range, as it contains a '-'
		range_start=${num/-*}
		range_end=${num/*-}
		range=$(seq $range_start 1 $range_end)
	else	# It has no range, its a single number
		range=$num
	fi
	# Parse all the numbers filled in range
	for r in $range;do
		ping -c1 $IP_PRE.$r 2>/dev/zero 1>/dev/zero && \
			echo "$IP_PRE.$r is up" || \
			echo "$IP_PRE.$r is down"
	done
done

./test.sh 15 30-37 42 ...

192.168.1.15
192.168.1.30
192.168.1.31
...
192.168.1.37
192.168.1.42

192.168.1.217

#!/bin/ksh
# Print Usage message and exit.
Usage() {
	printf 'Usage:\t%s [-t] lastIP\n\t%s [-t] LOWlastIP-HIGHlastIP\n' \
		"$IAm" "$IAm" >&2
	exit 1
}

BaseIP='192.168.1.'	# All but last component of desired IP address
IAm=${0##*/}		# Last component of script name for diagnostics
addon=0			# Default add-on if -t option is not present

# Parse options...
while getopts 't' opt
do      case "$opt" in
	(t)     addon=200;;
	(?)     Usage;;
	esac
done
shift $((OPTIND - 1))

# Process operand...
if [ $# -ne 1 ]
then	printf '%s: 1 operand required; found %d\n' "$IAm" $# >&2
	Usage
fi
# Verifying that the operand is in the correct format is left as an exercise
# for the reader.
low=$((${1%%-*} + addon))	# Set low end of last component of IP address.
high=$((${1##*-} + addon))	# Set high end...

# Loop through the requested IP addresses...
last="$low"
while [ "$last" -le "$high" ]
do	ip="$BaseIP$last"
	# ping, discard otuput, check exit status, and print results
	if ping -c 1 -t 1 "$ip" > /dev/null 2> /dev/null
	then	echo "${ip} is up"
	else	echo "${ip} is down"
	fi
	last=$((last + 1))
done