What is dash in terminal?

What is dash in terminal?

dash is the standard command interpreter for the system. Overview The shell is a command that reads lines from either a file or the terminal, interprets them, and generally executes other commands.

What does Colon Dash mean in bash?

It’s a parameter expansion, it means if the third argument is null or unset, replace it with what’s after :- $ x= $ echo ${x:-1} 1 $ echo $x $

What does the dash command do in Linux?

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.

What does ” Double Dash ” ( Double Dash ) mean in Bash?

However, the GNU implementation of getopt () and its getopt_long () extension as used by most GNU utilities including GNU grep (but not bash nor any of its builtins even though bash is the GNU shell) doesn’t do that by default unless there’s a POSIXLY_CORRECT variable in the environment.

When does the shell recognize a simple command?

Essentially though, a line is read and if the first word of the line (or after a control operator) is not a reserved word, then the shell has recognized a simple command. Otherwise, a complex command or some other special construct may have been recognized. If a simple command has been recognized, the shell performs the following actions:

What does ” F ” ( Double Dash ) mean in shell?

The first -f is taken as an option to rm, while the second is taken as the name of a file to remove as everything past — is not taken as an option. In POSIX-compliant utilities and getopt () implementations, options are not accepted after non-option arguments, so for instance: is required to look for lines matching pattern in the file called -f.

How does a login shell read a command?

A login shell first reads commands from the files /etc/profile and .profile if they exist. If the environment variable ENV is set on entry to an interactive shell, or is set in the .profile of a login shell, the shell next reads commands from the file named in ENV.