1RCSFILE(5) File Formats Manual RCSFILE(5)
2
6 rcsfile - format of RCS file
7
9 An RCS file's contents are described by the grammar below.
10 The text is free format: space, backspace, tab, newline, vertical tab,
12 form feed, and carriage return (collectively, white space) have no sig‐
13 nificance except in strings. However, white space cannot appear within
14 an id, num, or sym, and an RCS file must end with a newline.
15 Strings are enclosed by @. If a string contains a @, it must be dou‐
17 bled; otherwise, strings can contain arbitrary binary data.
18 The meta syntax uses the following conventions: `|' (bar) separates
20 alternatives; `{' and `}' enclose optional phrases; `{' and `}*'
21 enclose phrases that can be repeated zero or more times; `{' and '}+'
22 enclose phrases that must appear at least once and can be repeated;
23 Terminal symbols are in boldface; nonterminal symbols are in italics.
24 rcstext ::= admin {delta}* desc {deltatext}*
26 admin ::= head {num};
28 { branch {num}; }
29 access {id}*;
30 symbols {sym : num}*;
31 locks {id : num}*; {strict ;}
32 { comment {string}; }
33 { expand {string}; }
34 { newphrase }*
35 delta ::= num
37 date num;
38 author id;
39 state {id};
40 branches {num}*;
41 next {num};
42 { newphrase }*
43 desc ::= desc string
45 deltatext ::= num
47 log string
48 { newphrase }*
49 text string
50 num ::= {digit | .}+
52 digit ::= 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9
54 id ::= {num} idchar {idchar | num}*
56 sym ::= {digit}* idchar {idchar | digit}*
58 idchar ::= any visible graphic character except special
60 special ::= $ | , | . | : | ; | @
62 string ::= @{any character, with @ doubled}*@
64 newphrase ::= id word* ;
66 word ::= id | num | string | :
68 Identifiers are case sensitive. Keywords are in lower case only. The
70 sets of keywords and identifiers can overlap. In most environments RCS
71 uses the ISO 8859/1 encoding: visible graphic characters are codes
72 041-176 and 240-377, and white space characters are codes 010-015 and
73 040.
74 Dates, which appear after the date keyword, are of the form
76 Y.mm.dd.hh.mm.ss, where Y is the year, mm the month (01-12), dd the day
77 (01-31), hh the hour (00-23), mm the minute (00-59), and ss the second
78 (00-60). Y contains just the last two digits of the year for years
79 from 1900 through 1999, and all the digits of years thereafter. Dates
80 use the Gregorian calendar; times use UTC.
81 The newphrase productions in the grammar are reserved for future exten‐
83 sions to the format of RCS files. No newphrase will begin with any
84 keyword already in use.
85 The delta nodes form a tree. All nodes whose numbers consist of a sin‐
87 gle pair (e.g., 2.3, 2.1, 1.3, etc.) are on the trunk, and are linked
88 through the next field in order of decreasing numbers. The head field
89 in the admin node points to the head of that sequence (i.e., contains
90 the highest pair). The branch node in the admin node indicates the
91 default branch (or revision) for most RCS operations. If empty, the
92 default branch is the highest branch on the trunk.
93 All delta nodes whose numbers consist of 2n fields (n≥2) (e.g.,
95 3.1.1.1, 2.1.2.2, etc.) are linked as follows. All nodes whose first
96 2n-1 number fields are identical are linked through the next field in
97 order of increasing numbers. For each such sequence, the delta node
98 whose number is identical to the first 2n-2 number fields of the deltas
99 on that sequence is called the branchpoint. The branches field of a
100 node contains a list of the numbers of the first nodes of all sequences
101 for which it is a branchpoint. This list is ordered in increasing num‐
102 bers.
103 The following diagram shows an example of an RCS file's organization.
105 Head
107 |
108 |
109 v / \
110 --------- / \
111 / \ / \ | | / \ / \
112 / \ / \ | 2.1 | / \ / \
113 / \ / \ | | / \ / \
114 /1.2.1.3\ /1.3.1.1\ | | /1.2.2.2\ /1.2.2.1.1.1\
115 --------- --------- --------- --------- -------------
116 ^ ^ | ^ ^
117 | | | | |
118 | | v | |
119 / \ | --------- / \ |
120 / \ | \ 1.3 / / \ |
121 / \ ---------\ / / \-----------
122 /1.2.1.1\ \ / /1.2.2.1\
123 --------- \ / ---------
124 ^ | ^
125 | | |
126 | v |
127 | --------- |
128 | \ 1.2 / |
129 ----------------------\ /---------
130 \ /
131 \ /
132 |
133 |
134 v
135 ---------
136 \ 1.1 /
137 \ /
138 \ /
139 \ /
140
143 Author: Walter F. Tichy, Purdue University, West Lafayette, IN, 47907.
144 Manual Page Revision: 5.6; Release Date: 1995/06/05.
145 Copyright © 1982, 1988, 1989 Walter F. Tichy.
146 Copyright © 1990, 1991, 1992, 1993, 1994, 1995 Paul Eggert.
147
149 rcsintro(1), ci(1), co(1), ident(1), rcs(1), rcsclean(1), rcsdiff(1),
150 rcsmerge(1), rlog(1)
151 Walter F. Tichy, RCS--A System for Version Control, Software--Practice
152 & Experience 15, 7 (July 1985), 637-654.
153GNU 1995/06/05 RCSFILE(5)