1CO(1) General Commands Manual CO(1)
2
6 co - check out RCS revisions
7
9 co [ options ] file ...
10
12 Co retrieves revisions from RCS files. Each file name ending in `,v'
13 is taken to be an RCS file. All other files are assumed to be working
14 files. Co retrieves a revision from each RCS file and stores it into
15 the corresponding working file.
16 Pairs of RCS files and working files may be specified in 3 ways (see
18 also the example section).
19 1) Both the RCS file and the working file are given. The RCS file name
21 is of the form path1/workfile,v and the working file name is of the
22 form path2/workfile, where path1/ and path2/ are (possibly different or
23 empty) paths and workfile is a file name.
24 2) Only the RCS file is given. Then the working file is created in the
26 current directory and its name is derived from the name of the RCS file
27 by removing path1/ and the suffix `,v'.
28 3) Only the working file is given. Then the name of the RCS file is
30 derived from the name of the working file by removing path2/ and
31 appending the suffix `,v'.
32 If the RCS file is omitted or specified without a path, then co looks
34 for the RCS file first in the directory ./RCS and then in the current
35 directory.
36 Revisions of an RCS file may be checked out locked or unlocked. Locking
38 a revision prevents overlapping updates. A revision checked out for
39 reading or processing (e.g., compiling) need not be locked. A revision
40 checked out for editing and later checkin must normally be locked.
41 Locking a revision currently locked by another user fails. (A lock may
42 be broken with the rcs (1) command.) Co with locking requires the
43 caller to be on the access list of the RCS file, unless he is the owner
44 of the file or the superuser, or the access list is empty. Co without
45 locking is not subject to accesslist restrictions.
46 A revision is selected by number, checkin date/time, author, or state.
48 If none of these options are specified, the latest revision on the
49 trunk is retrieved. When the options are applied in combination, the
50 latest revision that satisfies all of them is retrieved. The options
51 for date/time, author, and state retrieve a revision on the selected
52 branch. The selected branch is either derived from the revision number
53 (if given), or is the highest branch on the trunk. A revision number
54 may be attached to one of the options -l, -p, -q, or -r.
55 A co command applied to an RCS file with no revisions creates a zero-
57 length file. Co always performs keyword substitution (see below).
58 -l[rev] locks the checked out revision for the caller. If omitted,
60 the checked out revision is not locked. See option -r for
61 handling of the revision number rev.
62 -p[rev] prints the retrieved revision on the std. output rather than
64 storing it in the working file. This option is useful when
65 co is part of a pipe.
66 -q[rev] quiet mode; diagnostics are not printed.
68 -ddate retrieves the latest revision on the selected branch whose
70 checkin date/time is less than or equal to date. The date
71 and time may be given in free format and are converted to
72 local time. Examples of formats for date:
73 22-April-1982, 17:20-CDT,
75 2:25 AM, Dec. 29, 1983,
76 Tue-PDT, 1981, 4pm Jul 21 (free format),
77 Fri, April 16 15:52:25 EST 1982 (output of ctime).
78 Most fields in the date and time may be defaulted. Co
80 determines the defaults in the order year, month, day, hour,
81 minute, and second (most to least significant). At least one
82 of these fields must be provided. For omitted fields that
83 are of higher significance than the highest provided field,
84 the current values are assumed. For all other omitted
85 fields, the lowest possible values are assumed. For exam‐
86 ple, the date "20, 10:30" defaults to 10:30:00 of the 20th
87 of the current month and current year. The date/time must
88 be quoted if it contains spaces.
89 -r[rev] retrieves the latest revision whose number is less than or
91 equal to rev. If rev indicates a branch rather than a revi‐
92 sion, the latest revision on that branch is retrieved. Rev
93 is composed of one or more numeric or symbolic fields sepa‐
94 rated by `.'. The numeric equivalent of a symbolic field is
95 specified with the -n option of the commands ci and rcs.
96 -sstate retrieves the latest revision on the selected branch whose
98 state is set to state.
99 -w[login] retrieves the latest revision on the selected branch which
101 was checked in by the user with login name login. If the
102 argument login is omitted, the caller's login is assumed.
103 -jjoinlist generates a new revision which is the join of the revisions
105 on joinlist. Joinlist is a comma-separated list of pairs of
106 the form rev2:rev3, where rev2 and rev3 are (symbolic or
107 numeric) revision numbers. For the initial such pair, rev1
108 denotes the revision selected by the options -l, ..., -w.
109 For all other pairs, rev1 denotes the revision generated by
110 the previous pair. (Thus, the output of one join becomes the
111 input to the next.)
112 For each pair, co joins revisions rev1 and rev3 with respect
114 to rev2. This means that all changes that transform rev2
115 into rev1 are applied to a copy of rev3. This is particu‐
116 larly useful if rev1 and rev3 are the ends of two branches
117 that have rev2 as a common ancestor. If rev1 < rev2 < rev3
118 on the same branch, joining generates a new revision which
119 is like rev3, but with all changes that lead from rev1 to
120 rev2 undone. If changes from rev2 to rev1 overlap with
121 changes from rev2 to rev3, co prints a warning and includes
122 the overlapping sections, delimited by the lines
123 <<<<<<< rev1, =======, and >>>>>>> rev3.
124 For the initial pair, rev2 may be omitted. The default is
126 the common ancestor. If any of the arguments indicate
127 branches, the latest revisions on those branches are
128 assumed. If the option -l is present, the initial rev1 is
129 locked.
130
132 Strings of the form $keyword$ and $keyword:...$ embedded in the text
133 are replaced with strings of the form $keyword: value $, where keyword
134 and value are pairs listed below. Keywords may be embedded in literal
135 strings or comments to identify a revision.
136 Initially, the user enters strings of the form $keyword$. On checkout,
138 co replaces these strings with strings of the form $keyword: value $.
139 If a revision containing strings of the latter form is checked back in,
140 the value fields will be replaced during the next checkout. Thus, the
141 keyword values are automatically updated on checkout.
142 Keywords and their corresponding values:
144 $Author$ The login name of the user who checked in the revision.
146 $Date$ The date and time the revision was checked in.
148 $Header$ A standard header containing the RCS file name, the revi‐
150 sion number, the date, the author, and the state.
151 $Locker$ The login name of the user who locked the revision (empty
153 if not locked).
154 $Log$ The log message supplied during checkin, preceded by a
156 header containing the RCS file name, the revision number,
157 the author, and the date. Existing log messages are NOT
158 replaced. Instead, the new log message is inserted after
159 $Log:...$. This is useful for accumulating a complete
160 change log in a source file.
161 $Revision$ The revision number assigned to the revision.
163 $Source$ The full pathname of the RCS file.
165 $State$ The state assigned to the revision with rcs -s or ci -s.
167
169 The RCS file name, the working file name, and the revision number
170 retrieved are written to the diagnostic output. The exit status always
171 refers to the last file checked out, and is 0 if the operation was suc‐
172 cessful, 1 otherwise.
173
175 Suppose the current directory contains a subdirectory `RCS' with an RCS
176 file `io.c,v'. Then all of the following commands retrieve the latest
177 revision from `RCS/io.c,v' and store it into `io.c'.
178 co io.c; co RCS/io.c,v; co io.c,v;
180 co io.c RCS/io.c,v; co io.c io.c,v;
181 co RCS/io.c,v io.c; co io.c,v io.c;
182
184 The working file inherits the read and execute permissions from the RCS
185 file. In addition, the owner write permission is turned on, unless the
186 file is checked out unlocked and locking is set to strict (see rcs
187 (1)).
188 If a file with the name of the working file exists already and has
190 write permission, co aborts the checkout if -q is given, or asks
191 whether to abort if -q is not given. If the existing working file is
192 not writable, it is deleted before the checkout.
193
195 The caller of the command must have write permission in the working
196 directory, read permission for the RCS file, and either read permission
197 (for reading) or read/write permission (for locking) in the directory
198 which contains the RCS file.
199 A number of temporary files are created. A semaphore file is created
201 in the directory of the RCS file to prevent simultaneous update.
202
204 Author: Walter F. Tichy, Purdue University, West Lafayette, IN, 47907.
205 Revision Number: 3.1 ; Release Date: 83/04/04 .
206 Copyright © 1982 by Walter F. Tichy.
207
209 ci (1), ident(1), rcs (1), rcsdiff (1), rcsintro (1), rcsmerge (1),
210 rlog (1), rcsfile (5), sccstorcs (8).
211 Walter F. Tichy, "Design, Implementation, and Evaluation of a Revision
212 Control System," in Proceedings of the 6th International Conference on
213 Software Engineering, IEEE, Tokyo, Sept. 1982.
214
216 The option -d gets confused in some circumstances, and accepts no date
217 before 1970. There is no way to suppress the expansion of keywords,
218 except by writing them differently. In nroff and troff, this is done by
219 embedding the null-character `\&' into the keyword.
220
222 The option -j does not work for files that contain lines with a single
223 `.'.
224Purdue University 6/29/83 CO(1)