CO(1) CO(1)
NAME
co - check out RCS revisions
SYNOPSIS
ccoo [options] file ...
DESCRIPTION
ccoo retrieves a revision from each RCS file and stores it into the cor-
responding working file.
Pathnames matching an RCS suffix denote RCS files; all others denote
working files. Names are paired as explained in ccii(1).
Revisions of an RCS file can be checked out locked or unlocked. Lock-
ing a revision prevents overlapping updates. A revision checked out
for reading or processing (e.g., compiling) need not be locked. A
revision checked out for editing and later checkin must normally be
locked. Checkout with locking fails if the revision to be checked out
is currently locked by another user. (A lock can be broken with
rrccss(1).) Checkout with locking also requires the caller to be on the
access list of the RCS file, unless he is the owner of the file or the
superuser, or the access list is empty. Checkout without locking is
not subject to accesslist restrictions, and is not affected by the
presence of locks.
A revision is selected by options for revision or branch number,
checkin date/time, author, or state. When the selection options are
applied in combination, ccoo retrieves the latest revision that satisfies
all of them. If none of the selection options is specified, ccoo
retrieves the latest revision on the default branch (normally the
trunk, see the -bb option of rrccss(1)). A revision or branch number can
be attached to any of the options -ff, -II, -ll, -MM, -pp, -qq, -rr, or -uu.
The options -dd (date), -ss (state), and -ww (author) retrieve from a sin-
gle branch, the selected branch, which is either specified by one of
-ff, ..., -uu, or the default branch.
A ccoo command applied to an RCS file with no revisions creates a zero-
length working file. ccoo always performs keyword substitution (see
below).
OOPPTTIIOONNSS
-rr[rev]
retrieves the latest revision whose number is less than or equal
to rev. If rev indicates a branch rather than a revision, the
latest revision on that branch is retrieved. If rev is omitted,
the latest revision on the default branch (see the -bb option of
rrccss(1)) is retrieved. If rev is $$, ccoo determines the revision
number from keyword values in the working file. Otherwise, a
revision is composed of one or more numeric or symbolic fields
separated by periods. If rev begins with a period, then the
default branch (normally the trunk) is prepended to it. If rev
is a branch number followed by a period, then the latest revi-
sion on that branch is used. The numeric equivalent of a sym-
bolic field is specified with the -nn option of the commands
ccii(1) and rrccss(1).
-ll[rev]
same as -rr, except that it also locks the retrieved revision for
the caller.
-uu[rev]
same as -rr, except that it unlocks the retrieved revision if it
was locked by the caller. If rev is omitted, -uu retrieves the
revision locked by the caller, if there is one; otherwise, it
retrieves the latest revision on the default branch.
-ff[rev]
forces the overwriting of the working file; useful in connection
with -qq. See also FILE MODES below.
-kkkkvv Generate keyword strings using the default form, e.g. $$RReevviissiioonn::
11..11 $$ for the RReevviissiioonn keyword. A locker's name is inserted in
the value of the HHeeaaddeerr, IIdd, and LLoocckkeerr keyword strings only as
a file is being locked, i.e. by ccii -ll and ccoo -ll. This is the
default.
-kkkkvvll Like -kkkkvv, except that a locker's name is always inserted if the
given revision is currently locked.
-kkkk Generate only keyword names in keyword strings; omit their val-
ues. See KEYWORD SUBSTITUTION below. For example, for the
RReevviissiioonn keyword, generate the string $$RReevviissiioonn$$ instead of
$$RReevviissiioonn:: 11..11 $$. This option is useful to ignore differences
due to keyword substitution when comparing different revisions
of a file. Log messages are inserted after $$LLoogg$$ keywords even
if -kkkk is specified, since this tends to be more useful when
merging changes.
-kkoo Generate the old keyword string, present in the working file
just before it was checked in. For example, for the RReevviissiioonn
keyword, generate the string $$RReevviissiioonn:: 11..11 $$ instead of $$RReevvii-
ssiioonn:: 11..11 $$ if that is how the string appeared when the file was
checked in. This can be useful for file formats that cannot
tolerate any changes to substrings that happen to take the form
of keyword strings.
-kkbb Generate a binary image of the old keyword string. This acts
like -kkoo, except it performs all working file input and output
in binary mode. This makes little difference on Posix and Unix
hosts, but on DOS-like hosts one should use rrccss -ii -kkbb to ini-
tialize an RCS file intended to be used for binary files. Also,
on all hosts, rrccssmmeerrggee(1) normally refuses to merge files when
-kkbb is in effect.
-kkvv Generate only keyword values for keyword strings. For example,
for the RReevviissiioonn keyword, generate the string 11..11 instead of
$$RReevviissiioonn:: 11..11 $$. This can help generate files in programming
languages where it is hard to strip keyword delimiters like
$$RReevviissiioonn:: $$ from a string. However, further keyword substitu-
tion cannot be performed once the keyword names are removed, so
this option should be used with care. Because of this danger of
losing keywords, this option cannot be combined with -ll, and the
owner write permission of the working file is turned off; to
edit the file later, check it out again without -kkvv.
-pp[rev]
prints the retrieved revision on the standard output rather than
storing it in the working file. This option is useful when ccoo
is part of a pipe.
-qq[rev]
quiet mode; diagnostics are not printed.
-II[rev]
interactive mode; the user is prompted and questioned even if
the standard input is not a terminal.
-dddate retrieves the latest revision on the selected branch whose
checkin date/time is less than or equal to date. The date and
time can be given in free format. The time zone LLTT stands for
local time; other common time zone names are understood. For
example, the following dates are equivalent if local time is
January 11, 1990, 8pm Pacific Standard Time, eight hours west of
Coordinated Universal Time (UTC):
88::0000 ppmm lltt
44::0000 AAMM,, JJaann.. 1122,, 11999900 default is UTC
11999900-0011-1122 0044::0000::0000++0000 ISO 8601 (UTC)
11999900-0011-1111 2200::0000::0000-0088 ISO 8601 (local time)
11999900//0011//1122 0044::0000::0000 traditional RCS format
TThhuu JJaann 1111 2200::0000::0000 11999900 LLTT output of ccttiimmee(3) + LLTT
TThhuu JJaann 1111 2200::0000::0000 PPSSTT 11999900 output of ddaattee(1)
FFrrii JJaann 1122 0044::0000::0000 GGMMTT 11999900
TThhuu,, 1111 JJaann 11999900 2200::0000::0000 -00880000 Internet RFC 822
1122-JJaannuuaarryy-11999900,, 0044::0000 WWEETT
Most fields in the date and time can be defaulted. The default
time zone is normally UTC, but this can be overridden by the -zz
option. The other defaults are determined in the order year,
month, day, hour, minute, and second (most to least signifi-
cant). At least one of these fields must be provided. For
omitted fields that are of higher significance than the highest
provided field, the time zone's current values are assumed. For
all other omitted fields, the lowest possible values are
assumed. For example, without -zz, the date 2200,, 1100::3300 defaults
to 10:30:00 UTC of the 20th of the UTC time zone's current month
and year. The date/time must be quoted if it contains spaces.
-MM[rev]
Set the modification time on the new working file to be the date
of the retrieved revision. Use this option with care; it can
confuse mmaakkee(1).
-ssstate
retrieves the latest revision on the selected branch whose state
is set to state.
-TT Preserve the modification time on the RCS file even if the RCS
file changes because a lock is added or removed. This option
can suppress extensive recompilation caused by a mmaakkee(1) depen-
dency of some other copy of the working file on the RCS file.
Use this option with care; it can suppress recompilation even
when it is needed, i.e. when the change of lock would mean a
change to keyword strings in the other working file.
-ww[login]
retrieves the latest revision on the selected branch which was
checked in by the user with login name login. If the argument
login is omitted, the caller's login is assumed.
-jjjoinlist
generates a new revision which is the join of the revisions on
joinlist. This option is largely obsoleted by rrccssmmeerrggee(1) but
is retained for backwards compatibility.
The joinlist is a comma-separated list of pairs of the form
rev2::rev3, where rev2 and rev3 are (symbolic or numeric) revi-
sion numbers. For the initial such pair, rev1 denotes the revi-
sion selected by the above options -ff, ..., -ww. For all other
pairs, rev1 denotes the revision generated by the previous pair.
(Thus, the output of one join becomes the input to the next.)
For each pair, ccoo joins revisions rev1 and rev3 with respect to
rev2. This means that all changes that transform rev2 into rev1
are applied to a copy of rev3. This is particularly useful if
rev1 and rev3 are the ends of two branches that have rev2 as a
common ancestor. If rev1 generates a new revision which is like rev3, but with all
changes that lead from rev1 to rev2 undone. If changes from
rev2 to rev1 overlap with changes from rev2 to rev3, ccoo reports
overlaps as described in mmeerrggee(1).
For the initial pair, rev2 can be omitted. The default is the
common ancestor. If any of the arguments indicate branches, the
latest revisions on those branches are assumed. The options -ll
and -uu lock or unlock rev1.
-VV Print RCS's version number.
-VVn Emulate RCS version n, where n can be 33, 44, or 55. This can be
useful when interchanging RCS files with others who are running
older versions of RCS. To see which version of RCS your corre-
spondents are running, have them invoke rrccss -VV; this works with
newer versions of RCS. If it doesn't work, have them invoke
rrlloogg on an RCS file; if none of the first few lines of output
contain the string bbrraanncchh:: it is version 3; if the dates' years
have just two digits, it is version 4; otherwise, it is version
5. An RCS file generated while emulating version 3 loses its
default branch. An RCS revision generated while emulating ver-
sion 4 or earlier has a time stamp that is off by up to 13
hours. A revision extracted while emulating version 4 or ear-
lier contains abbreviated dates of the form yy//mm//dd and can
also contain different white space and line prefixes in the sub-
stitution for $$LLoogg$$.
-xxsuffixes
Use suffixes to characterize RCS files. See ccii(1) for details.
-zzzone specifies the date output format in keyword substitution, and
specifies the default time zone for date in the -dddate option.
The zone should be empty, a numeric UTC offset, or the special
string LLTT for local time. The default is an empty zone, which
uses the traditional RCS format of UTC without any time zone
indication and with slashes separating the parts of the date;
otherwise, times are output in ISO 8601 format with time zone
indication. For example, if local time is January 11, 1990, 8pm
Pacific Standard Time, eight hours west of UTC, then the time is
output as follows:
option time output
-zz 11999900//0011//1122 0044::0000::0000 (default)
-zzLLTT 11999900-0011-1111 2200::0000::0000-0088
-zz++0055::3300 11999900-0011-1122 0099::3300::0000++0055::3300
The -zz option does not affect dates stored in RCS files, which
are always UTC.
KKEEYYWWOORRDD SSUUBBSSTTIITTUUTTIIOONN
Strings of the form $$keyword$$ and $$keyword::...$$ embedded in the text
are replaced with strings of the form $$keyword::value$$ where keyword and
value are pairs listed below. Keywords can be embedded in literal
strings or comments to identify a revision.
Initially, the user enters strings of the form $$keyword$$. On checkout,
ccoo replaces these strings with strings of the form $$keyword::value$$. If
a revision containing strings of the latter form is checked back in,
the value fields will be replaced during the next checkout. Thus, the
keyword values are automatically updated on checkout. This automatic
substitution can be modified by the -kk options.
Keywords and their corresponding values:
$$AAuutthhoorr$$
The login name of the user who checked in the revision.
$$DDaattee$$ The date and time the revision was checked in. With -zzzone a
numeric time zone offset is appended; otherwise, the date is
UTC.
$$HHeeaaddeerr$$
A standard header containing the full pathname of the RCS file,
the revision number, the date and time, the author, the state,
and the locker (if locked). With -zzzone a numeric time zone
offset is appended to the date; otherwise, the date is UTC.
$$IIdd$$ Same as $$HHeeaaddeerr$$, except that the RCS filename is without a
path.
$$LLoocckkeerr$$
The login name of the user who locked the revision (empty if not
locked).
$$LLoogg$$ The log message supplied during checkin, preceded by a header
containing the RCS filename, the revision number, the author,
and the date and time. With -zzzone a numeric time zone offset
is appended; otherwise, the date is UTC. Existing log messages
are not replaced. Instead, the new log message is inserted
after $$LLoogg::...$$. This is useful for accumulating a complete
change log in a source file.
Each inserted line is prefixed by the string that prefixes the
$$LLoogg$$ line. For example, if the $$LLoogg$$ line is "//// $$LLoogg::
ttaann..cccc $$", RCS prefixes each line of the log with "//// ". This
is useful for languages with comments that go to the end of the
line. The convention for other languages is to use a " ** " pre-
fix inside a multiline comment. For example, the initial log
comment of a C program conventionally is of the following form:
//**
** $$LLoogg$$
**//
For backwards compatibility with older versions of RCS, if the
log prefix is //** or ((** surrounded by optional white space,
inserted log lines contain a space instead of // or ((; however,
this usage is obsolescent and should not be relied on.
$$NNaammee$$ The symbolic name used to check out the revision, if any. For
example, ccoo -rrJJooee generates $$NNaammee:: JJooee $$. Plain ccoo generates
just $$NNaammee:: $$.
$$RRCCSSffiillee$$
The name of the RCS file without a path.
$$RReevviissiioonn$$
The revision number assigned to the revision.
$$SSoouurrccee$$
The full pathname of the RCS file.
$$SSttaattee$$
The state assigned to the revision with the -ss option of rrccss(1)
or ccii(1).
The following characters in keyword values are represented by escape
sequences to keep keyword strings well-formed.
char escape sequence
tab \\tt
newline \\nn
space \\004400
$$ \\004444
\\ \\\\
FFIILLEE MMOODDEESS
The working file inherits the read and execute permissions from the RCS
file. In addition, the owner write permission is turned on, unless -kkvv
is set or the file is checked out unlocked and locking is set to strict
(see rrccss(1)).
If a file with the name of the working file exists already and has
write permission, ccoo aborts the checkout, asking beforehand if possi-
ble. If the existing working file is not writable or -ff is given, the
working file is deleted without asking.
FILES ccoo accesses files much as ccii(1) does, except that it does not need to
read the working file unless a revision number of $$ is specified.
ENVIRONMENT RRCCSSIINNIITT
options prepended to the argument list, separated by spaces.
See ccii(1) for details.
DIAGNOSTICS The RCS pathname, the working pathname, and the revision number
retrieved are written to the diagnostic output. The exit status is
zero if and only if all operations were successful.
IIDDEENNTTIIFFIICCAATTIIOONN
Author: Walter F. Tichy.
Manual Page Revision: 1.1; Release Date: 1999/04/23.
Copyright (C) 1982, 1988, 1989 Walter F. Tichy.
Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995 Paul Eggert.
SEE ALSO
rcsintro(1), ci(1), ctime(3), date(1), ident(1), make(1), rcs(1),
rcsclean(1), rcsdiff(1), rcsmerge(1), rlog(1), rcsfile(5)
Walter F. Tichy, RCS-A System for Version Control, Software-Practice
& Experience 1155, 7 (July 1985), 637-654.
LLIIMMIITTSS
Links to the RCS and working files are not preserved.
There is no way to selectively suppress the expansion of keywords,
except by writing them differently. In nroff and troff, this is done
by embedding the null-character \\&& into the keyword.
GNU 1999/04/23 CO(1)