How do I get the difference between two dates in shell?

How do I get the difference between two dates in shell?

There’s a solution that almost works: use the %s date format of GNU date, which prints the number of seconds since 1970-01-01 00:00. These can be subtracted to find the time difference between two dates.

What is Korn shell known as?

The Korn shell is the UNIX shell (command execution program, often called a command interpreter ) that was developed by David Korn of Bell Labs as a comprehensive combined version of other major UNIX shells.

How is bash different than the Korn shell?

Korn shell uses the print command to print the message in the terminal. Bash shell uses the echo command to print the message in the terminal. Korn shell has better support to loop handling as compared to the Bash shell. The Korn shell is developed by David Korn and it’s older than the Bash shell.

What is the short name of Korn shell?

The Korn shell (ksh command) is backwardly compatible with the Bourne shell (bsh command) and contains most of the Bourne shell features as well as several of the best features of the C shell.

How do you find the difference between two timestamps in unix?

First, calculate convert the dates to be compared into unix timestamps:

1. date1=$(date –date=”2020-10-31 05:41:33″ “+%s”)
2. date2=$(date –date=”2020-11-01 05:41:33″ “+%s”)

How do you subtract dates in unix?

The easiest way is to convert the date to a unix time_t value (i.e. seconds since the beginning of the epoch, or ‘1-1-1970 00:00:00’), and then substract 30 days * 86400 seconds per day from that number. e.g. the following example uses set -x so that you can see the value of the D variable as it changes.

What is the latest version of ksh?

KornShell ( ksh ) is a Unix shell which was developed by David Korn at Bell Labs in the early 1980s and announced at USENIX on July 14, 1983….KornShell.

Which is better ksh or Bash?

Korn shell provides much better performance than Bash shell when dealing with the execution of scripts and commands. Bash shell provides decent performance when it comes to executing commands and scripts. Korn shell interpreter is located at /bin/ksh. Bash shell interpreter is located at /bin/bash.

Is ksh still used?

There are various versions of the Korn shell released till now like ksh88, ksh93, etc in order to compensate for the limitations of the older Korn shell. Since it contains various features like associative arrays, dealing with loops, print command, etc, it is still used widely especially by the old Linux/ Unix lovers.

How do you do arithmetic operations in bash?

Bash Script Program

1. #!/bin/bash.
2. #Basic arithmetic using expr.
3. echo “a=10, b=3”
4. echo “c is the value of addition c=a+b”
5. a=10.
6. b=3.
7. echo “c= `expr $a + $b`”