Command Reference Guide

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STANDARD Printed by: Nora Chuang [nchuang] STANDARD
/build/1111/BRICK/man1/!!!intro.1
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c
co(1) co(1)
NAME
co - check out RCS revisions
SYNOPSIS
co [options ] file ...
DESCRIPTION
co retrieves revisions from RCS files. Each file name 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 in the
corresponding working file (see also rcsintro(5)).
Revisions of an RCS file can be checked out locked or unlocked. Locking 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 checked in must normally be locked. Locking a revision currently locked
by another user fails (a lock can be broken with the rcs command, but poses inherent risks when indepen-
dent changes are being made simultaneously (see rcs(1)). co with locking requires the caller to be on the
access list of the RCS file unless: he is the owner of the file, a user with appropriate privileges, or the access
list is empty. co without locking is not subject to access list restrictions.
A revision is selected by number, check-in date/time, author, or state. If none of these options are
specified, the latest revision on the trunk is retrieved. When the options are applied in combination, the
latest revision that satisfies all of them is retrieved. 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. A revision number can be attached to the options -l
, -p, -q,or-r.
The caller of the command 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 that
contains the RCS file.
The working file inherits the read and execute permissions from the RCS file. In addition, the owner write
permission is turned on, unless the file is checked out unlocked and locking is set to strict
(see rcs(1)).
If a file with the name of the working file exists already and has write permission,
co aborts the check out
if
-q is given, or asks whether to abort if -q is not given. If the existing working file is not writable, it is
deleted before the check out.
A number of temporary files are created. A semaphore file is created in the directory of the
RCS file to
prevent simultaneous update.
A
co command applied to an RCS file with no revisions creates a zero-length file. co
always performs
keyword substitution(see below).
Options
-l[rev] Locks the checked out revision for the caller. If 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 rather than storing it in the working
file. This option is useful when co is part of a pipe.
-q[rev] Quiet mode; diagnostics are not printed.
-ddate Retrieves the latest revision on the selected branch whose check in 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:
Tue-PDT, 1981, 4pm Jul 21 (free format)
Fri April 16 15:52:25 EST 1982 (output of ctime(3C))
4/21/86 10:30am (format: mm/dd/yy hh:mm:ss)
Most fields in the date and time can be defaulted. co determines the defaults in the order
year, month, day, hour, minute, and second (from 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. Date/time fields can be delim-
ited by spaces or commas. If spaces are used, the string must be surrounded by double
quotes.
Section 1−−98 − 1 − HP-UX Release 11i: December 2000
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