RCSFILE(5RCS) COMMAND REFERENCE RCSFILE(5RCS)
NAME
rcsfile - format of RCS file
DESCRIPTION
An RCS file is an ASCII file. Its contents is described by
the grammar below. The text is free format, i.e., spaces,
tabs and new lines have no significance except in strings.
Strings are enclosed by @. If a string contains a @, it
must be doubled.
The meta syntax uses the following conventions: | (bar)
separates alternatives; { and } enclose optinal phrases; {
and }* enclose phrases that may be repeated zero or more
times; { and }+ enclose phrases that must appear at least
once and may be repeated; < and > enclose nonterminals.
<rcstext> ::= <admin> {<delta>}* <desc> {<deltatext>}*
<admin> ::= head {<num>};
access {<id>}*;
symbols {<id> : <num>}*;
locks {<id> : <num>}*;
comment {<string>};
<delta> ::= <num>
date <num>;
author <id>;
state {<id>};
branches {<num>}*;
next {<num>};
<desc> ::= desc <string>
<deltatext> ::= <num>
log <string>
text <string>
<num> ::= {<digit>{.}}+
<digit> ::= 0 | 1 | ... | 9
<id> ::= <letter>{<idchar>}*
<letter> ::= A | B | ... | Z | a | b | ... | z
<idchar> ::= Any printing ASCII character except space,
tab, carriage return, new line, and <special>.
<special> ::= ; | : | , | @
<string> ::= @{any ASCII character, with `@' doubled}*@
Printed 3/13/89 1
RCSFILE(5RCS) COMMAND REFERENCE RCSFILE(5RCS)
Identifiers are case sensitive. Keywords are in lower case
only. The sets of keywords and identifiers may overlap.
The <delta> nodes form a tree. All nodes whose numbers
consist of a single pair (e.g., 2.3, 2.1, 1.3, etc.) are on
the "trunk", and are linked through the "next" field in
order of decreasing numbers. The "head" field in the <admin>
node points to the head of that sequence (i.e., contains the
highest pair).
All <delta> nodes whose numbers consist of 2n fields (n>2)
(e.g., 3.1.1.1, 2.1.2.2, etc.) are linked as follows. All
nodes whose first (2n)-1 number fields are identical are
linked through the "next" field in order of increasing
numbers. For each such sequence, the <delta> node whose
number is identical to the first 2(n-1) number fields of the
deltas on that sequence is called the branchpoint. The
"branches" field of a node contains a list of the numbers of
the first nodes of all sequences for which it is a
branchpoint. This list is ordered in increasing numbers.
Example:
Head
|
|
v
---------
/ \ / \ | | / \ / \
/ \ / \ | 2.1 | / \ / \
/ \ / \ | | / \ / \
/1.2.1.3\ /1.3.1.1\ | | /1.2.2.2\ /1.2.2.1.1.1\
--------- --------- --------- --------- -------------
^ ^ | ^ ^
| | | | |
| | v | |
/ \ | --------- / \ |
/ \ | \ 1.3 / / \ |
/ \ ---------\ / / \-----------
/1.2.1.1\ \ / /1.2.2.1\
--------- \ / ---------
^ | ^
| | |
| v |
| --------- |
| \ 1.2 / |
----------------------\ /---------
\ /
\ /
|
|
v
---------
\ 1.1 /
\*(]W \*(]L 2
\*(]H \*(]D \*(]H
\ /
\ /
\ /
Fig. 1: A revision tree
Maximum Number of Revisions
When an RCS file contains 700 or more revisions, all RCS
commands except for ident and rlog -c will print a warning
message (if possible) saying that the maximum number of
revisions is about to be reached. When the file contains 719
revisions, no further checkins are allowed. This maximum
applies to the total number of revisions in all branches.
Starting a new branch will not release any space.
There are two things that can be done when this happens.
The first is to delete some of the revisions using the -o
flag of the rcs command. This should be done with some
care, making sure that significant modifications are kept
separate.
The other method of fixing this problem is to make a copy of
the RCS file and delete all of the old revisions in the
original file. For example, if the RCS file prog.c,v has 715
revisions (1.1 through 1.716), the following commands will
save the first 700 revisions in another file, and leave the
last 15 revisions where they can be easily found.
cp prog.c,v prog.old,v
rcs -o1.701-1.716 prog.old
rcs -o1.1-1.700 prog.c
Revision 1.348 can be retrieved by the command co -r 1.348
prog.old. Revisions after 1.700 can be checked out of
prog.c,v. Note that the rcs command may take a while to
delete 700 revisions.
SEE ALSO
ci(1rcs), co(1rcs), ident(1rcs), rlog(1rcs), rcs(1rcs),
rcsdiff(1rcs), rcsintro(1rcs), and rcsmerge(1rcs).
Printed 3/13/89 3
%%index%%
na:384,80;
de:464,2715;3635,4977;
se:8612,350;
%%index%%000000000080