BSD General Commands Manual
dash — command interpreter (shell)
dash [ −aCefnuvxIimqVEb] [+aCefnuvxIimqVEb] [ −o option_name] [+o option_name]
[command_file [argument ...]]
dash −c [ −aCefnuvxIimqVEb] [+aCefnuvxIimqVEb] [ −o option_name]
[+o option_name] command_string [command_name [argument ...]]
dash −s [ −aCefnuvxIimqVEb] [+aCefnuvxIimqVEb] [ −o option_name]
[+o option_name] [argument ...]
dash is the standard command interpreter for the system. The current version of dash is in the process of
being changed to conform with the POSIX 1003.2 and 1003.2a specifications for the shell. This version has
many features which make it appear similar in some respects to the Korn shell, but it is not a Korn shell clone
(see ksh(1)). Only features designated by POSIX, plus a few Berkeley extensions, are being incorporated
into this shell. This man page is not intended to be a tutorial or a complete specification of the shell.
The shell is a command that reads lines from either a file or the terminal, interprets them, and generally
executes other commands. It is the program that is running when a user logs into the system (although a user
can select a different shell with the chsh(1) command). The shell implements a language that has flow con-
trol constructs, a macro facility that provides a variety of features in addition to data storage, along with built
in history and line editing capabilities. It incorporates many features to aid interactive use and has the advan-
tage that the interpretative language is common to both interactive and non-interactive use (shell scripts).
That is, commands can be typed directly to the running shell or can be put into a file and the file can be
executed directly by the shell.
If no args are present and if the standard input of the shell is connected to a terminal (or if the −i flag is set),
and the −c option is not present, the shell is considered an interactive shell. An interactive shell generally
prompts before each comma