1CO(1) General Commands Manual CO(1)
2
6 co - check out RCS revisions
7
9 co [options] file ...
10
12 co retrieves a revision from each RCS file and stores it into the cor‐
13 responding working file.
14 Pathnames matching an RCS suffix denote RCS files; all others denote
16 working files. Names are paired as explained in ci(1).
17 Revisions of an RCS file can be checked out locked or unlocked. Lock‐
19 ing a revision prevents overlapping updates. A revision checked out
20 for reading or processing (e.g., compiling) need not be locked. A
21 revision checked out for editing and later checkin must normally be
22 locked. Checkout with locking fails if the revision to be checked out
23 is currently locked by another user. (A lock can be broken with
24 rcs(1).) Checkout with locking also requires the caller to be on the
25 access list of the RCS file, unless he is the owner of the file or the
26 superuser, or the access list is empty. Checkout without locking is
27 not subject to accesslist restrictions, and is not affected by the
28 presence of locks.
29 A revision is selected by options for revision or branch number,
31 checkin date/time, author, or state. When the selection options are
32 applied in combination, co retrieves the latest revision that satisfies
33 all of them. If none of the selection options is specified, co
34 retrieves the latest revision on the default branch (normally the
35 trunk, see the -b option of rcs(1)). A revision or branch number can
36 be attached to any of the options -f, -I, -l, -M, -p, -q, -r, or -u.
37 The options -d (date), -s (state), and -w (author) retrieve from a sin‐
38 gle branch, the selected branch, which is either specified by one of
39 -f, ..., -u, or the default branch.
40 A co command applied to an RCS file with no revisions creates a zero-
42 length working file. co always performs keyword substitution (see
43 below).
44
46 -r[rev]
47 retrieves the latest revision whose number is less than or equal
48 to rev. If rev indicates a branch rather than a revision, the
49 latest revision on that branch is retrieved. If rev is omitted,
50 the latest revision on the default branch (see the -b option of
51 rcs(1)) is retrieved. If rev is $, co determines the revision
52 number from keyword values in the working file. Otherwise, a
53 revision is composed of one or more numeric or symbolic fields
54 separated by periods. If rev begins with a period, then the
55 default branch (normally the trunk) is prepended to it. If rev
56 is a branch number followed by a period, then the latest revi‐
57 sion on that branch is used. The numeric equivalent of a sym‐
58 bolic field is specified with the -n option of the commands
59 ci(1) and rcs(1).
60 -l[rev]
62 same as -r, except that it also locks the retrieved revision for
63 the caller.
64 -u[rev]
66 same as -r, except that it unlocks the retrieved revision if it
67 was locked by the caller. If rev is omitted, -u retrieves the
68 revision locked by the caller, if there is one; otherwise, it
69 retrieves the latest revision on the default branch.
70 -f[rev]
72 forces the overwriting of the working file; useful in connection
73 with -q. See also FILE MODES below.
74 -kkv Generate keyword strings using the default form, e.g. $Revision:
76 5.13 $ for the Revision keyword. A locker's name is inserted in
77 the value of the Header, Id, and Locker keyword strings only as
78 a file is being locked, i.e. by ci -l and co -l. This is the
79 default.
80 -kkvl Like -kkv, except that a locker's name is always inserted if the
82 given revision is currently locked.
83 -kk Generate only keyword names in keyword strings; omit their val‐
85 ues. See KEYWORD SUBSTITUTION below. For example, for the
86 Revision keyword, generate the string $Revision$ instead of
87 $Revision: 5.13 $. This option is useful to ignore differences
88 due to keyword substitution when comparing different revisions
89 of a file. Log messages are inserted after $Log$ keywords even
90 if -kk is specified, since this tends to be more useful when
91 merging changes.
92 -ko Generate the old keyword string, present in the working file
94 just before it was checked in. For example, for the Revision
95 keyword, generate the string $Revision: 1.1 $ instead of $Revi‐
96 sion: 5.13 $ if that is how the string appeared when the file
97 was checked in. This can be useful for file formats that cannot
98 tolerate any changes to substrings that happen to take the form
99 of keyword strings.
100 -kb Generate a binary image of the old keyword string. This acts
102 like -ko, except it performs all working file input and output
103 in binary mode. This makes little difference on Posix and Unix
104 hosts, but on DOS-like hosts one should use rcs -i -kb to ini‐
105 tialize an RCS file intended to be used for binary files. Also,
106 on all hosts, rcsmerge(1) normally refuses to merge files when
107 -kb is in effect.
108 -kv Generate only keyword values for keyword strings. For example,
110 for the Revision keyword, generate the string 5.13 instead of
111 $Revision: 5.13 $. This can help generate files in programming
112 languages where it is hard to strip keyword delimiters like
113 $Revision: $ from a string. However, further keyword substitu‐
114 tion cannot be performed once the keyword names are removed, so
115 this option should be used with care. Because of this danger of
116 losing keywords, this option cannot be combined with -l, and the
117 owner write permission of the working file is turned off; to
118 edit the file later, check it out again without -kv.
119 -p[rev]
121 prints the retrieved revision on the standard output rather than
122 storing it in the working file. This option is useful when co
123 is part of a pipe.
124 -q[rev]
126 quiet mode; diagnostics are not printed.
127 -I[rev]
129 interactive mode; the user is prompted and questioned even if
130 the standard input is not a terminal.
131 -ddate retrieves the latest revision on the selected branch whose
133 checkin date/time is less than or equal to date. The date and
134 time can be given in free format. The time zone LT stands for
135 local time; other common time zone names are understood. For
136 example, the following dates are equivalent if local time is
137 January 11, 1990, 8pm Pacific Standard Time, eight hours west of
138 Coordinated Universal Time (UTC):
139 8:00 pm lt
141 4:00 AM, Jan. 12, 1990 default is UTC
142 1990-01-12 04:00:00+00 ISO 8601 (UTC)
143 1990-01-11 20:00:00-08 ISO 8601 (local time)
144 1990/01/12 04:00:00 traditional RCS format
145 Thu Jan 11 20:00:00 1990 LT output of ctime(3) + LT
146 Thu Jan 11 20:00:00 PST 1990 output of date(1)
147 Fri Jan 12 04:00:00 GMT 1990
148 Thu, 11 Jan 1990 20:00:00 -0800 Internet RFC 822
149 12-January-1990, 04:00 WET
150 Most fields in the date and time can be defaulted. The default
152 time zone is normally UTC, but this can be overridden by the -z
153 option. The other defaults are determined in the order year,
154 month, day, hour, minute, and second (most to least signifi‐
155 cant). At least one of these fields must be provided. For
156 omitted fields that are of higher significance than the highest
157 provided field, the time zone's current values are assumed. For
158 all other omitted fields, the lowest possible values are
159 assumed. For example, without -z, the date 20, 10:30 defaults
160 to 10:30:00 UTC of the 20th of the UTC time zone's current month
161 and year. The date/time must be quoted if it contains spaces.
162 -M[rev]
164 Set the modification time on the new working file to be the date
165 of the retrieved revision. Use this option with care; it can
166 confuse make(1).
167 -sstate
169 retrieves the latest revision on the selected branch whose state
170 is set to state.
171 -S Turns on same user locks. When this is enabled the user cannot
173 check out the same file twice.
174 -T Preserve the modification time on the RCS file even if the RCS
176 file changes because a lock is added or removed. This option
177 can suppress extensive recompilation caused by a make(1) depen‐
178 dency of some other copy of the working file on the RCS file.
179 Use this option with care; it can suppress recompilation even
180 when it is needed, i.e. when the change of lock would mean a
181 change to keyword strings in the other working file.
182 -w[login]
184 retrieves the latest revision on the selected branch which was
185 checked in by the user with login name login. If the argument
186 login is omitted, the caller's login is assumed.
187 -jjoinlist
189 generates a new revision which is the join of the revisions on
190 joinlist. This option is largely obsoleted by rcsmerge(1) but
191 is retained for backwards compatibility.
192 The joinlist is a comma-separated list of pairs of the form
194 rev2:rev3, where rev2 and rev3 are (symbolic or numeric) revi‐
195 sion numbers. For the initial such pair, rev1 denotes the revi‐
196 sion selected by the above options -f, ..., -w. For all other
197 pairs, rev1 denotes the revision generated by the previous pair.
198 (Thus, the output of one join becomes the input to the next.)
199 For each pair, co joins revisions rev1 and rev3 with respect to
201 rev2. This means that all changes that transform rev2 into rev1
202 are applied to a copy of rev3. This is particularly useful if
203 rev1 and rev3 are the ends of two branches that have rev2 as a
204 common ancestor. If rev1<rev2<rev3 on the same branch, joining
205 generates a new revision which is like rev3, but with all
206 changes that lead from rev1 to rev2 undone. If changes from
207 rev2 to rev1 overlap with changes from rev2 to rev3, co reports
208 overlaps as described in merge(1).
209 For the initial pair, rev2 can be omitted. The default is the
211 common ancestor. If any of the arguments indicate branches, the
212 latest revisions on those branches are assumed. The options -l
213 and -u lock or unlock rev1.
214 -V Print RCS's version number.
216 -Vn Emulate RCS version n, where n can be 3, 4, or 5. This can be
218 useful when interchanging RCS files with others who are running
219 older versions of RCS. To see which version of RCS your corre‐
220 spondents are running, have them invoke rcs -V; this works with
221 newer versions of RCS. If it doesn't work, have them invoke
222 rlog on an RCS file; if none of the first few lines of output
223 contain the string branch: it is version 3; if the dates' years
224 have just two digits, it is version 4; otherwise, it is version
225 5. An RCS file generated while emulating version 3 loses its
226 default branch. An RCS revision generated while emulating ver‐
227 sion 4 or earlier has a time stamp that is off by up to 13
228 hours. A revision extracted while emulating version 4 or ear‐
229 lier contains abbreviated dates of the form yy/mm/dd and can
230 also contain different white space and line prefixes in the sub‐
231 stitution for $Log$.
232 -xsuffixes
234 Use suffixes to characterize RCS files. See ci(1) for details.
235 -zzone specifies the date output format in keyword substitution, and
237 specifies the default time zone for date in the -ddate option.
238 The zone should be empty, a numeric UTC offset, or the special
239 string LT for local time. The default is an empty zone, which
240 uses the traditional RCS format of UTC without any time zone
241 indication and with slashes separating the parts of the date;
242 otherwise, times are output in ISO 8601 format with time zone
243 indication. For example, if local time is January 11, 1990, 8pm
244 Pacific Standard Time, eight hours west of UTC, then the time is
245 output as follows:
246 option time output
248 -z 1990/01/12 04:00:00 (default)
249 -zLT 1990-01-11 20:00:00-08
250 -z+05:30 1990-01-12 09:30:00+05:30
251 The -z option does not affect dates stored in RCS files, which
253 are always UTC.
254
256 Strings of the form $keyword$ and $keyword:...$ embedded in the text
257 are replaced with strings of the form $keyword:value$ where keyword and
258 value are pairs listed below. Keywords can be embedded in literal
259 strings or comments to identify a revision.
260 Initially, the user enters strings of the form $keyword$. On checkout,
262 co replaces these strings with strings of the form $keyword:value$. If
263 a revision containing strings of the latter form is checked back in,
264 the value fields will be replaced during the next checkout. Thus, the
265 keyword values are automatically updated on checkout. This automatic
266 substitution can be modified by the -k options.
267 Keywords and their corresponding values:
269 $Author$
271 The login name of the user who checked in the revision.
272 $Date$ The date and time the revision was checked in. With -zzone a
274 numeric time zone offset is appended; otherwise, the date is
275 UTC.
276 $Header$
278 A standard header containing the full pathname of the RCS file,
279 the revision number, the date and time, the author, the state,
280 and the locker (if locked). With -zzone a numeric time zone
281 offset is appended to the date; otherwise, the date is UTC.
282 $Id$ Same as $Header$, except that the RCS filename is without a
284 path.
285 $Locker$
287 The login name of the user who locked the revision (empty if not
288 locked).
289 $Log$ The log message supplied during checkin, preceded by a header
291 containing the RCS filename, the revision number, the author,
292 and the date and time. With -zzone a numeric time zone offset
293 is appended; otherwise, the date is UTC. Existing log messages
294 are not replaced. Instead, the new log message is inserted
295 after $Log:...$. This is useful for accumulating a complete
296 change log in a source file.
297 Each inserted line is prefixed by the string that prefixes the
299 $Log$ line. For example, if the $Log$ line is “// $Log:
300 tan.cc $”, RCS prefixes each line of the log with “// ”. This
301 is useful for languages with comments that go to the end of the
302 line. The convention for other languages is to use a “ ∗ ” pre‐
303 fix inside a multiline comment. For example, the initial log
304 comment of a C program conventionally is of the following form:
305 /∗
307 ∗ $Log$
308 ∗/
309 For backwards compatibility with older versions of RCS, if the
311 log prefix is /∗ or (∗ surrounded by optional white space,
312 inserted log lines contain a space instead of / or (; however,
313 this usage is obsolescent and should not be relied on.
314 $Name$ The symbolic name used to check out the revision, if any. For
316 example, co -rJoe generates $Name: Joe $. Plain co generates
317 just $Name: $.
318 $RCSfile$
320 The name of the RCS file without a path.
321 $Revision$
323 The revision number assigned to the revision.
324 $Source$
326 The full pathname of the RCS file.
327 $State$
329 The state assigned to the revision with the -s option of rcs(1)
330 or ci(1).
331 The following characters in keyword values are represented by escape
333 sequences to keep keyword strings well-formed.
334 char escape sequence
336 tab \t
337 newline \n
338 space \040
339 $ \044
340 \ \\
341
343 The working file inherits the read and execute permissions from the RCS
344 file. In addition, the owner write permission is turned on, unless -kv
345 is set or the file is checked out unlocked and locking is set to strict
346 (see rcs(1)).
347 If a file with the name of the working file exists already and has
349 write permission, co aborts the checkout, asking beforehand if possi‐
350 ble. If the existing working file is not writable or -f is given, the
351 working file is deleted without asking.
352
354 co accesses files much as ci(1) does, except that it does not need to
355 read the working file unless a revision number of $ is specified.
356
358 RCSINIT
359 options prepended to the argument list, separated by spaces.
360 See ci(1) for details.
361
363 The RCS pathname, the working pathname, and the revision number
364 retrieved are written to the diagnostic output. The exit status is
365 zero if and only if all operations were successful.
366
368 Author: Walter F. Tichy.
369 Manual Page Revision: 5.13; Release Date: 1995/06/01.
370 Copyright © 1982, 1988, 1989 Walter F. Tichy.
371 Copyright © 1990, 1991, 1992, 1993, 1994, 1995 Paul Eggert.
372
374 rcsintro(1), ci(1), ctime(3), date(1), ident(1), make(1), rcs(1),
375 rcsclean(1), rcsdiff(1), rcsmerge(1), rlog(1), rcsfile(5)
376 Walter F. Tichy, RCS--A System for Version Control, Software--Practice
377 & Experience 15, 7 (July 1985), 637-654.
378
380 Links to the RCS and working files are not preserved.
381 There is no way to selectively suppress the expansion of keywords,
383 except by writing them differently. In nroff and troff, this is done
384 by embedding the null-character \& into the keyword.
385GNU 1995/06/01 CO(1)