4.8 Invoking the Shell

The command interpreter for the Bourne shell ( sh ) or the Korn shell ( ksh ) can be invoked as follows:

sh [ options ] [ arguments ]

ksh [ options ] [ arguments ]

ksh and sh can execute commands from a terminal (when -i is specified), from a file (when the first argument is an executable script), or from standard input (if no arguments remain or if -s is specified).

Arguments

Arguments are assigned in order to the positional parameters $1 , $2 , etc. If array assignment is in effect ( -A or +A ), arguments are assigned as array elements. If the first argument is an executable script, commands are read from it, and remaining arguments are assigned to $1 , $2 , etc.

Options

-c str

Read commands from string str .

-i

Create an interactive shell (prompt for input).

-p

Start up as a privileged user (i.e., don't process $HOME/.profile ).

-r

Create a restricted shell (same as rksh or rsh ).

-s

Read commands from standard input; output from built-in commands goes to file descriptor 1; all other shell output goes to file descriptor 2.

The remaining options to sh and ksh are listed under the set built-in command.