Argument list processing

The rest of the flag arguments are interpreted as follows:

-b

Forces a ``break'' from option processing, causing any further shell arguments to be treated as non-option arguments. The remaining arguments will not be interpreted as shell options. This may be used to pass options to a shell script without confusion or possible subterfuge. The shell will not run a set-user ID script without this option.

-c

Commands are read from the following argument (which must be present, and must be a single argument), stored in the command shell variable for reference, and executed. Any remaining arguments are placed in the argv shell variable.

-d

The shell loads the directory stack from ~/.cshdirs as described under Startup and shutdown, whether or not it is a login shell. (+)

-Dname[=value]

Sets the environment variable name to value. (Domain/OS only) (+)

-e

The shell exits if any invoked command terminates abnormally or yields a non-zero exit status.

-f

The shell ignores ~/.tcshrc, and thus starts faster.

-F

The shell uses fork(2) instead of vfork(2) to spawn processes. (Convex/OS only) (+)

-i

The shell is interactive and prompts for its top-level input, even if it appears to not be a terminal. Shells are interactive without this option if their inputs and outputs are terminals.

-l

The shell is a login shell. Only applicable if -l is the only flag specified.

-m

The shell loads ~/.tcshrc even if it does not belong to the effective user. Newer versions of su(1) can pass -m to the shell. (+)

-n

The shell parses commands but does not execute them. This aids in debugging shell scripts.

-q

The shell accepts SIGQUIT (see Signal handling) and behaves when it is used under a debugger. Job control is disabled. (u)

-s

Command input is taken from the standard input.

-t

The shell reads and executes a single line of input. A `\' may be used to escape the newline at the end of this line and continue onto another line.

-v

Sets the verbose shell variable, so that command input is echoed after history substitution.

-x

Sets the echo shell variable, so that commands are echoed immediately before execution.

-V

Sets the verbose shell variable even before executing ~/.tcshrc.

-X

Is to -x as -V is to -v.

After processing of flag arguments, if arguments remain but none of the -c, -i, -s, or -t options were given, the first argument is taken as the name of a file of commands, or ``script'', to be executed. The shell opens this file and saves its name for possible resubstitution by `$0'. Since many systems use either the standard version 6 or version 7 shells whose shell scripts are not compatible with this shell, the shell uses such a `standard' shell to execute a script whose first character is not a `#', i.e. which does not start with a comment.

Remaining arguments are placed in the argv shell variable.

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