Simple way to add the date and time to the file name:

A simple and powerful alternative method of appending a date and time to a file name  is to assign the syntax of the date command to a variable.

Later, then we can insert the variable name in the brackets of the $() syntax 

construction, and the shell will  interpret it in the same way.

For eg:

$ day=”date +%T-%d_%m_%Y”

To check the value of the variable,

$ echo $day

To create the “example_team_file” with the time and date appended to the file name now 

the variable can be used.

Output of the same is pasted below for better understanding:

     

Output:

[root ~/good/test 10:50:12] # day="date +%T-%d_%m_%y"

[root ~/good/test 10:51:21] # echo $day

date +%T-%d_%m_%y

[root ~/good/test 10:52:35] # touch example_file$($day)

[root ~/good/test 10:52:49] # ls -l

total 4

-rw-r--r-- 1 root root 0 Aug 20 10:52 example_file10:52:49-20_08_13

[root ~/good/test 10:52:51] # touch test_file1$($day) test_file2$($day) test_file3$($day) test_file4$($day) test_file5$($day)

[root ~/good/test 10:54:00] # ls -l

total 24

-rw-r--r-- 1 root root 0 Aug 20 10:52 example_file10:52:49-20_08_13

-rw-r--r-- 1 root root 0 Aug 20 10:54 test_file110:54:00-20_08_13

-rw-r--r-- 1 root root 0 Aug 20 10:54 test_file210:54:00-20_08_13

-rw-r--r-- 1 root root 0 Aug 20 10:54 test_file310:54:00-20_08_13

-rw-r--r-- 1 root root 0 Aug 20 10:54 test_file410:54:00-20_08_13

-rw-r--r-- 1 root root 0 Aug 20 10:54 test_file510:54:00-20_08_13

Note: Kindly note, the variable is assigned will be temporary. Once logged 

         out, the variable does not exist.