https://invisible-island.net/ded/cm_tools/
checkin - rcs check-in utility
checkin [options] [file-specifications]
Checkin is an extension of the RCS utility ci. It uses the file's
modification date rather than the current date as the RCS delta-date.
Checkin uses the rcs utility ci. It is normally invoked from the
rcsput script, but may be invoked in a standalone manner. Checkin
differs from ci primarily in its treatment of the delta date: after
invoking ci, checkin modifies the delta-date in the archive to reflect
the file's modification date.
This is the fundamental advantage offered by checkin. The ordinary rcs
methodology uses the current date as the check-in date. This works
well only for large projects in which a central project administrator
is responsible for controlling the versions of source files. It does
not work well for small projects, for which rcs's primary advantage is
its compact storage of multiple versions of a file.
By using the file's modification date as a reference, you can more
easily back up to a meaningful version - by date, rather than version
number.
If the archive directory (e.g., "./RCS") does not exist, checkin
creates it before invoking the ci program.
The rcs ci and co utilities work to a degree in set-uid mode (i.e., the
"u+s" protection is set on the programs). However, the code assumes
that the effective uid is root, and does not concern itself with
maintaining file ownership.
The checkin package is able to run as a set-uid process for any
particular user (e.g., the administrator of a project). For example,
suppose that /proj is the location of project-specific tools, and is
owned by admin. Then (running as the admin user):
cp checkin /proj # admin now owns this copy
chmod 4755 /proj/checkin # sets u+s mode
Thereafter, users who invoke /proj/checkin will have the rights of
admin - for this application. They may check into rcs any files which
they own, into archives which admin owns. Checkin will maintain
admin's ownership of the archive files, and the user's ownership of his
working files.
If checkin does not need the set-uid rights (e.g., if the user already
owns the archive), checkin resets its effective uid to the user's.
This permits a single copy of checkin to be used for both configuration
management as well as individual developers.
Checkin provides support for shared files by using rcs's access lists,
and providing special handling for set-uid operation:
o When you first archive a file using checkin, it invokes the rcs
administrative utility to initialize the access list of the file.
It puts the effective user into the list.
o If checkin is running in set-uid mode, it puts the real user on the
access list as well.
With the access list is initialized, only those users who appear on an
access list may place locks on files, even when running in set-uid
mode.
Before attempting to create or lock an archive file, checkin looks
first for the directory-level permissions which may be set with the
permit utility. If they exist, checkin limits further access rights to
those permitted.
Checkin recognizes all of the "ci" options.
If the "-k" option is used, checkin supplies a default log-message
FROM_KEYS
Options specific to checkin are:
-B directs checkin to ignore the baseline version. Normally, checkin
supplies a default version number which augments that of ci, by
looking at the baseline version.
-D causes it to display the actions it would perform, but not to do
them (e.g., invocation of rcs and ci).
-Mfilename
provide the check-in message in the given file. Normally ci
prompts you for a multiline message.
If the input is not a terminal, checkin assumes that is a pipe, and
passes the text (escaped) to ci. That is done best in a script.
For random use, to supply the same check-in message for more than
one file, the -M option lets you provide the message via a file.
Checkin is used exactly as one would use ci. Place a lock on the file
using the "-l" option with ci (or with co) when you wish to edit a
file. Check the file in using the "-u" option to retain a working copy
after modification.
Checkin is a C-language program. It invokes ci (with an explicit path,
to protect against mishaps in set-uid mode), and performs pre- and
postprocessing of the archive and working file to determine the version
to which the file's modification date applies.
Checkin uses the following environment variables:
RCS_BASE
is used to specify a default value for initial revision numbers.
If the user does not specify the initial version number of a file,
ci assigns the value "1.1". This is used to support the use of
module-level version numbers, while preserving the relationship
between changes and revisions: a new version is made only if the
file is changed.
The directory-level revision set by the permit utility may override
this environment variable. See baseline and permit for more
details.
RCS_COMMENT
is set to a string controlling the initial setting of the rcs "-c"
option. For example, the strings
setenv RCS_COMMENT '/.c/ *> /'
and
setenv RCS_COMMENT '/.d/# /,/.bas/REM /'
define comment-prefixes for ".c", ".d" and ".bas" suffixes. (The
suffix is delimited with the first "." in the leaf-name).
RCS_DIR
if defined, specifies the directory in which rcs archive files are
found. Normally files are found in "./RCS".
TZ is the POSIX time zone, which is overridden internally so that file
modification dates are independent of the local time zone.
Checkin uses the following files
ci the RCS check-in program
rcs the RCS administrative program
None.
baseline, rcsput, permit, ded, ci (1), co (1), rcs (1)
Thomas E. Dickey <dickey@invisible-island.net>
CHECKIN(1)