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Name: Port Checker
Language: Bash
Purpose: Check to see if a port is available based on either the port # or program name passed.
Notes: Requires root privileges due to “p” switch being used in netstat

[/pre]

 
 #!/bin/bash
 
 # Script is used to determine if a port is used.
 # Usage: portcheck 
 # Executes netstat -ntlup | grep  to do checking.
 # Returned text is stored in a variable.  If variable is empty,
 # port is not in used.  Otherwise, port is being used.
 
 # Get the username of the person running script
 USER=`id -un`
 
 # Root is required to run netstat -ntlup
 if [ "$USER" != "root" ]; then
 	echo "Root privileges required."
 else
 	NET=`netstat -ntlup | grep $1`
 
 	if [ -z "$NET" ]; then
 		echo "Port is free"
 	else
 		echo $NET
 	fi
 fi[/port][/port][/pre]
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