The main advantage of 'ksh' over the traditional Unix shell is in its use as a programming language.
In most Unix shells (command interpreters), this is represented by the vertical bar character.
Under the Unix shells, here documents are generally used as a way of providing input to commands.
Here are some commands given to a command line interpreter (Unix shell).
Many later command-line interpreters have been inspired by the Unix shell.
These new features proved very popular, and many of them have since been copied by other Unix shells.
It is intended to provide a fully functional programming language as a Unix shell.
The various Unix shells maintain a record of the commands issued by the user during the current session.
It is used in a similar way to many other programs run in the Unix shell.
One important use of this signal is in job control in the Unix shell.