CO(1RCS) COMMAND REFERENCE CO(1RCS)
NAME
co - check out RCS revisions
SYNOPSIS
co [ -P ] [ -ddate ] [ -jjoinlist ] [ -l[rev] ] [ -p[rev] ]
[ -q[rev] ] [ -r[rev] ] [ -sstate ] [ -ulogin ] [ -w[login]
] filename ...
DESCRIPTION
Co retrieves revisions from RCS files. Each filename ending
in ,v is taken to be an RCS file. All other files are
assumed to be working files. Co retrieves a revision from
each RCS file and stores it into the corresponding working
file.
You may specify pairs of RCS files and working files in
three ways:
1) Give both the RCS filename and the working filename. The
format of an RCS filename is: pathname1/workfilename,v. The
format of a working filename is: pathname2/workfilename.
Pathname1/ and pathname2/ are (possibly different or empty)
paths and workfilename is a filename.
2) Give only the RCS filename. The working file is created
in the current directory and its name is derived from the
name of the RCS file by removing pathname1/ and the suffix
,v.
3) Give only the working filename. The name of the RCS file
is derived from the name of the working file by removing
pathname2/ and appending the suffix ,v.
If you omit the RCS filename or specify it without a path,
co looks for the RCS file in the directory ./RCS and then in
the current directory.
You may check out revisions of an RCS file locked or
unlocked. Locking a revision prevents overlapping updates.
You need not lock a revision that is checked out for reading
or processing (for example, compiling). A revision you
checked out for editing and later checkin should be locked.
Co won't let you lock a revision that is currently locked by
another user. (A lock may be broken with the rcs(1rcs)
command.)
To check out a file locked, you must be:
1) On the access list of the RCS file, or
2) The owner of the file, or
3) Logged in as the superuser.
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CO(1RCS) COMMAND REFERENCE CO(1RCS)
You can also checkout a file locked if the access list is
empty. Co without locking is not subject to access-list
restrictions.
You may select a revision by number, checkin date/time,
author, or state. When these options are applied in
combination, the latest revision that satisfies all of them
is retrieved. If you don't specify any of these options co
retrieves the latest revision on the trunk.
The options for date/time, author, and state retrieve a
revision on the selected branch. The selected branch is
either derived from the revision number (if given), or is
the highest branch on the trunk. You may specify a revision
number with one of the options: -l, -p, -q, or -r.
A co command applied to an RCS file with no revisions
creates a zero-length file. Co always performs keyword
substitution (see below).
Co creates the working file with the same read and execute
permissions as the RCS file. In addition, write permission
for the owner of the file is turned on, unless the file is
checked out unlocked and locking is set to strict (see
rcs(1rcs)).
If a file with the name of the working file exists already
and you have write permission, co:
1) Aborts the checkout if -q is given, or
2) Asks whether to abort if -q is not given.
If the working file exists but is not writable, it is
deleted before the checkout.
KEYWORD SUBSTITUTION
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. (Note: the Locker keyword is only expanded in the
working file that was actually checked out with the lock.)
Keywords may be embedded in literal strings or comments to
identify a revision.
Initially, you enter strings of the form $keyword$. On
checkout, co 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 are
replaced during the next checkout. Thus, the keyword values
are automatically updated on checkout.
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CO(1RCS) COMMAND REFERENCE CO(1RCS)
Keywords and their corresponding values are:
$Author$
The loginname of the user who checked in the revision.
$Date$
The date and time the revision was checked in.
$Header$
A standard header containing the RCS filename, the
revision number, the date, the author, and the state.
$Locker$
The loginname of the user who locked the revision (empty
if not locked).
$Log$
The log message supplied during checkin, preceded by a
header containing the RCS filename, the revision number,
the author, and the date. Existing log messages are not
replaced. Instead, the new log message is inserted
after $Log:...$. This is useful for accumulating a
complete change log in a source file.
$Revision$
The revision number assigned to the revision.
$Source$
The full pathname of the RCS file.
$State$
The state assigned to the revision with rcs -s or ci -s.
OPTIONS
-P Causes the access and modification dates of the working
file and RCS to be the same as the original RCS file.
See CAVEATS.
-ddate
Retrieves the latest revision on the selected branch
whose checkin date/time is less than or equal to date.
The date and time may be given in free format and are
converted to local time. Examples of formats for date
are:
22-April-1982, 17:20-CDT,
2:25 AM, Dec. 29, 1983,
Tue-PDT, 1981, 4pm Jul 21 (free format),
Fri, April 16 15:52:25 EST 1982 (output of ctime).
Most fields in the date and time may be omitted. Co
determines the defaults in this order: year, month, day,
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CO(1RCS) COMMAND REFERENCE CO(1RCS)
hour, minute, and second (most to least significant). At
least one of these fields must be provided. For omitted
fields that are of higher significance than the highest
provided field, the current values are assumed. For all
other omitted fields, the lowest possible values are
assumed. For example, the date 20, 10:30 defaults to
10:30:00 of the 20th of the current month and current
year. The date/time must be quoted if it contains
spaces.
-jjoinlist
Generates a new revision which is the join of the
revisions on joinlist. Joinlist is a comma-separated
list of pairs of the form rev2:rev3, where rev2 and rev3
are (symbolic or numeric) revision numbers.
For the initial such pair, rev1 denotes the revision
selected by the options -l, ..., -r. 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, co 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 < rev2 < rev3 are on the same branch,
joining them 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, co prints a warning and
includes the overlapping sections, delimited by the
lines <<<<<<< rev1, =======, and >>>>>>> rev3.
For the initial pair you may omit rev2 and the following
colon, in which case the common ancestor of rev1 and
rev3 is used for rev2. If you omit rev2 but leave the
following colon, rev1 is used for rev2 as well as for
rev1.
If any of the arguments indicate branches, the latest
revisions on those branches are assumed. If the option
-l is present, the initial rev1 is locked.
-l[rev]
Locks the checked out revision for the caller. If -l is
omitted, the checked out revision is not locked. See
option -r for handling of the revision number rev.
-p[rev]
Prints the retrieved revision on the standard output
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CO(1RCS) COMMAND REFERENCE CO(1RCS)
rather than storing it in the working file. This option
is useful when co is part of a pipe (|) or when you want
the output displayed on your terminal.
-q[rev]
Quiet mode. Diagnostics are not printed.
-r[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. Rev is composed of one or more numeric or
symbolic fields separated by a dot (.). The numeric
equivalent of a symbolic field is specified with the -n
option of the commands ci and rcs.
-sstate
Retrieves the latest revision on the selected branch
whose state is state.
-ulogin
When locking a revision, use login as the locker instead
of the invoker's login name. This allows creating
separate working branches without requiring all lockers
to be present to check out the files.
-w[login]
Retrieves the latest revision on the selected branch
that was checked in by the user with loginname login. If
login is omitted, the caller's login is assumed.
EXAMPLES
Suppose the current directory contains a subdirectory RCS
with an RCS file io.c,v. Then all of the following commands
retrieve the latest revision from RCS/io.c,v and store it
into io.c:
co io.c; co RCS/io.c,v; co io.c,v;
co io.c RCS/io.c,v; co io.c io.c,v;
co RCS/io.c,v io.c; co io.c,v io.c;
FILES
,*, Lock file; exists during checkout.
Prevents others from working on the
same file.
,RCSt$$ Temporary file for storing working
file data during retrieval. $$ is
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CO(1RCS) COMMAND REFERENCE CO(1RCS)
the process id.
DIAGNOSTICS
The RCS filename, the working filename, and the revision
number retrieved are written to the diagnostic output.
RETURN VALUE
[NO_ERRS] Command completed without error.
[NP_ERR] An error occurred that was not a system
error. Execution terminated.
CAVEATS
To checkout a revision, you must have write permission in
the working directory, read permission for the RCS file, and
either read permission (for reading) or read/write
permission (for locking) in the directory which contains the
RCS file.
The option -j does not work for files that contain lines
with a single dot (.).
The option -d gets confused in some circumstances, and
accepts no date earlier than 1970. There is no way to
suppress the expansion of keywords, except by writing them
differently. In nroff(1), this is done by embedding the
null-character into the keyword.
In order to interface correctly with make(1), the working
file is always newer than the RCS file after a checkout.
The maximum number of revisions that can be stored in a
single RCS file is 719. When there are more than 700
revisions in a file, a warning message is printed on the
terminal (if possible) every time an RCS command works on
the file. See the manual page for rcsfile(5rcs) for
information on what action to take in this case.
On older versions of RCS, the maximum number of revisions
that can be stored in a single RCS file is 239. No warning
message is displayed on the terminal if that number is
exceeded.
The -P option is supplied so that make does not think that a
file has been changed just because it was checked out. This
causes make to do less work, but it can cause problems if
the values of any of the RCS keyword values are used. For
example, if a revision logging system is used to store the
version numbers of source files into the object code, these
numbers may not be correct if the -P option is used.
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CO(1RCS) COMMAND REFERENCE CO(1RCS)
Unless the -l option is given, the Locker keyword is not
expanded.
SEE ALSO
ci(1rcs), ident(1rcs), make(1), rlog(1rcs), rcs(1rcs),
rcsdiff(1rcs), rcsintro(1rcs), rcsmerge(1rcs),
rcsfile(5rcs).
Printed 10/17/86 7
%%index%%
na:72,64;
sy:136,434;
de:570,2152;2866,2728;5738,1189;
op:6927,934;8005,3027;11176,1456;
ex:12632,442;
fi:13074,352;13570,47;
di:13617,201;
rv:13818,244;
ca:14062,1967;16173,102;
se:16275,390;
%%index%%000000000226