Two scripts to check port conditions under BASH shell

These days need to do Linux TCP port check script, found that netstat, NC command, although good, but not intuitive, and the port is a bit more trouble to check, hands-on learning to do two scripts. One is to check the port condition in the form of a parameter and another to scan the port using a configuration file. Recorded for easy use later.

First, nc_check.sh

#!/bin/bashcat./check_port|while read Linedo nc-z ' uname-n ' $line >/dev/null 2>&1 if [$?-eq 0];then Echo "$line OK." Else echo "$line Failed." Fidone

Create a Check_port file in the current directory before use, as follows:

Cat check_port123345456

All TCP detection ports follow one record per line into a file. Execution effect:

[Email protected] ~]#. nc_check123 OK345 OK456 Failed

The program checks all the ports in the list again, successful OK, failed failed

Second, netstat_check.sh

#!/bin/bashdeclare -a chk_tcp_cmd= ' netstat -tln|egrep 0.0.0.0|awk  ' {print $4} ' | awk -f:  ' {print $2} ' |sort -n ' declare -a port_no_existsdeclare -i  current_port=0for tcp_port in [email protected]do  #IS  NUMBER expr  "$ Tcp_port " + 0 >/dev/null 2>&1 if [ " $? "  !=  "0"  ];then  echo  "$TCP _port not a number."   exit 1 fi port_no_exists[$CURRENT _port]= $TCP _port for lsn_port in   $CHK _tcp_cmd  do  if [  $TCP _port ==  $LSN _port ];then    unset port_no_exists[$CURRENT _port]   break  fi  done   ((current_port++)) doneif [ ${#PORT_NO_EXISTS [@]} -gt 0 ];then echo  " Tcp ports ${port_no_exists[@]} failed. "  exit 1fiExit 0 

When used, the port number is added directly after the script as a parameter, and if multiple port numbers are scanned, each port number is separated by a space. If one of the parameters is not a number, the program terminates. Execution effect:

[[Email protected] ~]#./netstat_check.sh 789

The scanned port has no output.

[email protected] ~]#./netstat_check.sh 123 456 789TCP Port 123 456 failed.

The program lists all the failed ports.

[[email protected] ~]#./netstat_check.sh 123 Hello 456hello not a number.

The program output error is not a number.

This article is from "Balsam Pear" blog, please make sure to keep this source http://golehuang.blog.51cto.com/7499/1768264

Two scripts to check port conditions under BASH shell