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command substitution

HowTo: Bash Extract Filename And Extension In Unix / Linux

I have setup a shell variable called dest="/nas100/backups/servers/z/zebra/mysql.tgz". How do I find out filename (mysql.tgz) and extension (.tgz) in bash program running under Linux or Unix operating systems?
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HowTo: Bash Shell Split String Into Array

How do I split string based on delimiter into array under Bash shell?
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Bash: Assign Output of Shell Command To Variable

How do I assign the output of a shell command to a shell variable under Unix like operating system? For example, I want to store the date command output to a variable called $now. How do you do that?
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KSH for Syntax

Can you explains UNIX ksh for loop syntax which can repeatedly execute a block of statements with a simple ksh script example?
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How to: Add or display today’s date from a shell script

Q. How can I display or show today's UNIX computer date from a shell script using echo command? How do I store date command output to a variable?

A. Date command is use to print or set the system date and time under Linux/Unix like operating systems. However some time you need to include today's date in shell script. You need to use command substitution in your shell script to display today's date. Bash/sh shell performs the expansion by executing command and replacing the command substitution with the standard output
of the command, with any trailing newlines deleted. Command substitution allows the output of a command to replace the command name. You can use following syntax:

For example, type the following at shell prompt to display today's date:
$ echo "Today is $(date)"

Today is Sat Jan 28 15:48:11 IST 2006

Here is sample script, that stores today's date in TODAY and hostname in HOST variable:

echo "-----------------------------------------------------"
echo "Date: $TODAY                     Host:$HOST"
echo "-----------------------------------------------------"
# add rest code...

Save above script and execute it. See working shell script that notify admin user if Linux/FreeBSD system load crossed certain limit