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Full Discussion: How to Create a shell script to test the telnet connection status
Top Forums Shell Programming and Scripting How to Create a shell script to test the telnet connection status Post 302299021 by pludi on Thursday 19th of March 2009 03:23:46 AM
Old 03-19-2009
Please use [code ][/code] (sans the space) tags for source and listings, it's easier to read.
Quote:
Originally Posted by yhcheong
Code:
exec 3>/dev/tcp/${10.x.x.x}/2071
if [ $? -eq 0 ]
then
    echo "Telnet accepting connections"
else
    echo "Telnet connections not possible"
fi

bash: /dev/tcp/${10.x.x.x}/2071: bad substitution.
The ${MACHINE} that I used was in preparation for the loop that you'll need for that many machines (it's substituted by the value of the variable MACHINE)

Change it like this and try again
Code:
MACHINE=10.0.0.1 # Change to what ever you need
exec 3>/dev/tcp/${MACHINE}/2071
if [ $? -eq 0 ]
then
    echo "Telnet accepting connections"
else
    echo "Telnet connections not possible"
fi

 

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LEARN ABOUT PHP

kernel-install

KERNEL-INSTALL(8)						  kernel-install						 KERNEL-INSTALL(8)

NAME

       kernel-install - Add and remove kernel and initramfs images to and from /boot

SYNOPSIS

       kernel-install COMMAND KERNEL-VERSION [KERNEL-IMAGE]

DESCRIPTION

       kernel-install is used to install and remove kernel and initramfs images to and from /boot.

       kernel-install will execute the files located in the directory /usr/lib/kernel/install.d/ and the local administration directory
       /etc/kernel/install.d/. All files are collectively sorted and executed in lexical order, regardless of the directory in which they live.
       However, files with identical filenames replace each other. Files in /etc/kernel/install.d/ take precedence over files with the same name
       in /usr/lib/kernel/install.d/. This can be used to override a system-supplied executables with a local file if needed; a symbolic link in
       /etc/kernel/install.d/ with the same name as an executable in /usr/lib/kernel/install.d/, pointing to /dev/null, disables the executable
       entirely. Executables must have the extension ".install"; other extensions are ignored.

       An executable should return 0 on success. It may also return 77 to cause the whole operation to terminate (executables later in lexical
       order will be skipped).

COMMANDS

       The following commands are understood:

       add KERNEL-VERSION KERNEL-IMAGE
	   kernel-install creates the directory /boot/MACHINE-ID/KERNEL-VERSION/ and calls executables from /usr/lib/kernel/install.d/*.install
	   and /etc/kernel/install.d/*.install with the arguments

	       add KERNEL-VERSION 
		   /boot/MACHINE-ID/KERNEL-VERSION/ KERNEL-IMAGE

	   The kernel-install plugin 50-depmod.install runs depmod for the KERNEL-VERSION.

	   The kernel-install plugin 90-loaderentry.install copies KERNEL-IMAGE to /boot/MACHINE-ID/KERNEL-VERSION/linux. It also creates a boot
	   loader entry according to the boot loader specification in /boot/loader/entries/MACHINE-ID-KERNEL-VERSION.conf. The title of the entry
	   is the PRETTY_NAME parameter specified in /etc/os-release or /usr/lib/os-release (if the former is missing), or "Linux KERNEL-VERSION",
	   if unset. If the file initrd is found next to the linux file, the initrd will be added to the configuration.

       remove KERNEL-VERSION
	   Calls executables from /usr/lib/kernel/install.d/*.install and /etc/kernel/install.d/*.install with the arguments

	       remove KERNEL-VERSION /boot/MACHINE-ID/KERNEL-VERSION/

	   kernel-install removes the entire directory /boot/MACHINE-ID/KERNEL-VERSION/ afterwards.

	   The kernel-install plugin 90-loaderentry.install removes the file /boot/loader/entries/MACHINE-ID-KERNEL-VERSION.conf.

EXIT STATUS

       If every executable returns 0 or 77, 0 is returned, and a non-zero failure code otherwise.

FILES

       /usr/lib/kernel/install.d/*.install /etc/kernel/install.d/*.install
	   Drop-in files which are executed by kernel-install.

       /etc/kernel/cmdline /proc/cmdline
	   The content of the file /etc/kernel/cmdline specifies the kernel command line to use. If that file does not exist, /proc/cmdline is
	   used.

       /etc/machine-id
	   The content of the file specifies the machine identification MACHINE-ID.

       /etc/os-release /usr/lib/os-release
	   The content of the file specifies the operating system title PRETTY_NAME.

SEE ALSO

       machine-id(5), os-release(5), Boot loader specification[1]

NOTES

	1. Boot loader specification
	   https://www.freedesktop.org/wiki/Specifications/BootLoaderSpec

systemd 237															 KERNEL-INSTALL(8)
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