Here are several different ways to test a TCP port without telnet.
BASH (man page)
$ cat < /dev/tcp/127.0.0.1/22
SSH-2.0-OpenSSH_5.3
^C
$ cat < /dev/tcp/127.0.0.1/23
| function convertMS( milliseconds ) { | |
| var day, hour, minute, seconds; | |
| seconds = Math.floor(milliseconds / 1000); | |
| minute = Math.floor(seconds / 60); | |
| seconds = seconds % 60; | |
| hour = Math.floor(minute / 60); | |
| minute = minute % 60; | |
| day = Math.floor(hour / 24); | |
| hour = hour % 24; | |
| return { |
| #!/bin/bash | |
| # Author Sachin Verma | |
| ##Validate below variable based on env. | |
| TOMCAT_USER=root | |
| TOMCAT_HOME="/u01/apache-tomcat-8.5.24" | |
| SHUTDOWN_WAIT=45 | |
| TOMCAT_WEB_APPS_DIR=$TOMCAT_HOME'/webapps' | |
| WEB_APP=$TOMCAT_WEB_APPS_DIR'/reports' |
Here are several different ways to test a TCP port without telnet.
$ cat < /dev/tcp/127.0.0.1/22
SSH-2.0-OpenSSH_5.3
^C
$ cat < /dev/tcp/127.0.0.1/23
| package main.java.com.Documentum; | |
| import java.io.ByteArrayOutputStream; | |
| import java.io.IOException; | |
| import java.io.InputStream; | |
| import java.sql.Blob; | |
| import java.sql.SQLException; | |
| import java.util.HashMap; | |
| import java.util.Map; | |
| import java.util.Properties; |