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2.1.8 Misc common options

Other common options are -I, -q, -T, -V, -w, -x.

-I

This option enables interactive mode. More precisely, it forces interactive mode, whereby RCS commands believe that their standard input is a terminal, normally a precondition for displaying a prompt to receive input (such as a log message on checkin). The intention of -I is for scripting situations where standard input is actually not a terminal but you know beforehand (without prompting) that input is needed and you are ready to provide it on standard input anyway.

-q

This option enables quiet mode. Commands work silently (unless there is an error condition), and suppress warnings and prompts.

-T

This option controls how some commands (see Invoking ci, see Invoking co, see Invoking rcs, see Invoking rcsclean) timestamp the RCS file. Normally, RCS commands set the RCS file’s timestamp when modifying it in the “natural” way (without taking any particular care). With -T, on the other hand, the commands either preserve the timestamp (for standalone lock/unlock operations), or use the timestamp of the working file (for ci).

This can be useful if the RCS file is found in a makefile target’s list of prerequisites (see Rule Syntax in The GNU Make Manual), that is, if some target should be rebuilt if the RCS file is newer than it. In that case, you can do ‘rcs -u -T’, for example, to unlock a revision in the RCS file without triggering a recompilation.

See Stamp resolution, for details on support for subsecond resolution.

-V

Behave like --version, i.e., display command version information and exit successfully. NB: This option is obsolete and its support will be removed in some future release.

-Vn

n specifies the RCS (major) version to emulate. Valid values for n are: 3, 4, 5. Version 5 is the current version, so -V5 does nothing special.

In versions prior to 5, RCS outputs ‘\t’ (tab, U+09) between the ‘:’ (colon) and the value (for keyword substitution) instead of space, uses the RCS file comment string to prefix each line in the Log expansion instead of computing it on the fly from the input text, writes/reads localtime instead of UTC, and displays slightly different output for rlog.

For version 4, the Header expansion unconditionally includes Locker: locker, as if the kvl substitution mode were specified (see Substitution mode option).

For version 3, the Header expansion omits the directories from the filename and says only Locked instead of the state.

-wlogin

Some commands accept an option of the form ‘-wlogin’ to specify the login name of the author of a revision, i.e., “who” is responsible.

-xsuff

Specify suff as the slash-separated list of file name suffixes used to recognize an RCS file. The default value is ‘,v/’, that is, first try with ‘,v’ then try with an empty suffix.

This basename search occurs within (i.e., starting from the beginning) the larger directory search loop, which comprises two candidates: d/RCS and d, where d is the directory component of the working file name. For example, given the working file a.c in the current directory, RCS tries, in order, these candidates:

./RCS/a.c,v
./RCS/a.c
./a.c,v
./a.c

Note that the last candidate is impossible (and is in fact discarded), because the working and RCS files cannot have the same name.