{ "mode": "man", "parameter": "rcsfile", "section": "5", "url": "https://www.chedong.com/phpMan.php/man/rcsfile/5/json", "generated": "2026-05-30T07:09:19Z", "sections": { "NAME": { "content": "rcsfile - RCS file format\n", "subsections": [] }, "DESCRIPTION": { "content": "An RCS file's contents are described by the grammar below.\n\nThe text is free format: space, backspace, tab, newline, vertical tab, form feed, and car‐\nriage return (collectively, white space) have no significance except in strings. However,\nwhite space cannot appear within an id, num, or sym, and an RCS file must end with a newline.\n\nStrings are enclosed by @. If a string contains a @, it must be doubled; otherwise, strings\ncan contain arbitrary binary data.\n\nThe meta syntax uses the following conventions: `|' (bar) separates alternatives; `{' and `}'\nenclose optional phrases; `{' and `}*' enclose phrases that can be repeated zero or more\ntimes; `{' and '}+' enclose phrases that must appear at least once and can be repeated; Ter‐\nminal symbols are in boldface; nonterminal symbols are in italics.\n\nrcstext ::= admin {delta}* desc {deltatext}*\n\nadmin ::= head {num};\n{ branch {num}; }\naccess {id}*;\nsymbols {sym : num}*;\nlocks {id : num}*; {strict ;}\n{ integrity{intstring}; }\n{ comment {string}; }\n{ expand {string}; }\n\ndelta ::= num\ndate num;\nauthor id;\nstate {id};\nbranches {num}*;\nnext {num};\n{ commitid sym; }\n\ndesc ::= desc string\n\ndeltatext ::= num\nlog string\ntext string\n\nnum ::= {digit | .}+\n\ndigit ::= 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9\n\nid ::= {idchar | .}+\n\nsym ::= {idchar}+\n\nidchar ::= any visible graphic character except special\n\nspecial ::= $ | , | . | : | ; | @\n\nstring ::= @{any character, with @ doubled}*@\n\nword ::= id | num | string | :\n\nintchar ::= any character, except @\n\nthirdp ::= ^L {intchar}*\n\nintstring ::= @ {intchar}* {thirdp}* @\n\nIn releases prior to 5.8 (2011-08-30), the grammar included the newphrase production and used\nit in the admin, delta and deltatext productions. This allowed third-party programs to in‐\nteroperate with RCS by storing opaque (to RCS) data in the file. As of 5.8, in the name of\nprogress (towards more systematic file integrity support), the only area reserved for third-\nparty interop is in the (string) value of the integrity field, specifically after the first", "subsections": [ { "name": "^L (formfeed)", "content": "contain @.\n\nIdentifiers are case sensitive. Keywords are in lower case only. The sets of keywords and\nidentifiers can overlap. In most environments RCS uses the ISO 8859/1 encoding: visible\ngraphic characters are codes 041-176 and 240-377, and white space characters are codes\n010-015 and 040.\n\nDates, which appear after the date keyword, are of the form Y.mm.dd.hh.mm.ss, where Y is the\nyear, mm the month (01-12), dd the day (01-31), hh the hour (00-23), mm the minute (00-59),\nand ss the second (00-60). Y contains just the last two digits of the year for years from\n1900 through 1999, and all the digits of years thereafter. Dates use the Gregorian calendar;\ntimes use UTC.\n\nThe delta nodes form a tree. All nodes whose numbers consist of a single pair (e.g., 2.3,\n2.1, 1.3, etc.) are on the trunk, and are linked through the next field in order of decreas‐\ning numbers. The head field in the admin node points to the head of that sequence (i.e.,\ncontains the highest pair). The branch node in the admin node indicates the default branch\n(or revision) for most RCS operations. If empty, the default branch is the highest branch on\nthe trunk.\n\nAll delta nodes whose numbers consist of 2n fields (n≥2) (e.g., 3.1.1.1, 2.1.2.2, etc.) are\nlinked as follows. All nodes whose first 2n-1 number fields are identical are linked through\nthe next field in order of increasing numbers. For each such sequence, the delta node whose\nnumber is identical to the first 2n-2 number fields of the deltas on that sequence is called\nthe branchpoint. The branches field of a node contains a list of the numbers of the first\nnodes of all sequences for which it is a branchpoint. This list is ordered in increasing\nnumbers.\n\nThe following diagram shows an example of an RCS file's organization.\n\nHead\n|\n|\nv / \\\n--------- / \\\n/ \\ / \\ | | / \\ / \\\n/ \\ / \\ | 2.1 | / \\ / \\\n/ \\ / \\ | | / \\ / \\\n/1.2.1.3\\ /1.3.1.1\\ | | /1.2.2.2\\ /1.2.2.1.1.1\\\n--------- --------- --------- --------- -------------\n^ ^ | ^ ^\n| | | | |\n| | v | |\n/ \\ | --------- / \\ |\n/ \\ | \\ 1.3 / / \\ |\n/ \\ ---------\\ / / \\-----------\n/1.2.1.1\\ 1.3.1 \\ / /1.2.2.1\\ 1.2.2.1.1\n--------- \\ / ---------\n^ | ^\n| | |\n| v |\n| --------- |\n| \\ 1.2 / |\n----------------------\\ /---------\n1.2.1 \\ / 1.2.2\n\\ /\n|\n|\nv\n---------\n\\ 1.1 /\n\\ /\n\\ /\n\\ /\n\n" } ] }, "IDENTIFICATION": { "content": "Author: Walter F. Tichy.\nManual Page Revision: 5.10.1; Release Date: 2022-02-19.\nCopyright © 2010-2022 Thien-Thi Nguyen.\nCopyright © 1990, 1991, 1992, 1993, 1994, 1995 Paul Eggert.\nCopyright © 1982, 1988, 1989 Walter F. Tichy.\n", "subsections": [] }, "SEE ALSO": { "content": "ci(1), co(1), ident(1), rcs(1), rcsclean(1), rcsdiff(1), rcsmerge(1), rlog(1).\n\nWalter F. Tichy, RCS--A System for Version Control, Software--Practice & Experience 15, 7\n(July 1985), 637-654.\n\nThe full documentation for RCS is maintained as a Texinfo manual. If the info(1) and RCS\nprograms are properly installed at your site, the command\n\ninfo rcs\n\nshould give you access to the complete manual. Additionally, the RCS homepage:\n\nhttp://www.gnu.org/software/rcs/\n\nhas news and links to the latest release, development site, etc.\n\n\n\nGNU RCS 5.10.1 2022-02-19 RCSFILE(5)", "subsections": [] } }, "summary": "rcsfile - RCS file format", "flags": [], "examples": [], "see_also": [ { "name": "ci", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/ci/1/json" }, { "name": "co", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/co/1/json" }, { "name": "ident", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/ident/1/json" }, { "name": "rcs", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/rcs/1/json" }, { "name": "rcsclean", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/rcsclean/1/json" }, { "name": "rcsdiff", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/rcsdiff/1/json" }, { "name": "rcsmerge", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/rcsmerge/1/json" }, { "name": "rlog", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/rlog/1/json" }, { "name": "info", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/info/1/json" } ] }