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diff --git a/Documentation/git-rev-parse.txt b/Documentation/git-rev-parse.txt new file mode 100644 index 0000000000..7757abe621 --- /dev/null +++ b/Documentation/git-rev-parse.txt @@ -0,0 +1,289 @@ +git-rev-parse(1) +================ + +NAME +---- +git-rev-parse - Pick out and massage parameters + + +SYNOPSIS +-------- +'git-rev-parse' [ --option ] <args>... + +DESCRIPTION +----------- + +Many git porcelainish commands take mixture of flags +(i.e. parameters that begin with a dash '-') and parameters +meant for underlying `git-rev-list` command they use internally +and flags and parameters for other commands they use as the +downstream of `git-rev-list`. This command is used to +distinguish between them. + + +OPTIONS +------- +--revs-only:: + Do not output flags and parameters not meant for + `git-rev-list` command. + +--no-revs:: + Do not output flags and parameters meant for + `git-rev-list` command. + +--flags:: + Do not output non-flag parameters. + +--no-flags:: + Do not output flag parameters. + +--default <arg>:: + If there is no parameter given by the user, use `<arg>` + instead. + +--verify:: + The parameter given must be usable as a single, valid + object name. Otherwise barf and abort. + +--sq:: + Usually the output is made one line per flag and + parameter. This option makes output a single line, + properly quoted for consumption by shell. Useful when + you expect your parameter to contain whitespaces and + newlines (e.g. when using pickaxe `-S` with + `git-diff-\*`). + +--not:: + When showing object names, prefix them with '{caret}' and + strip '{caret}' prefix from the object names that already have + one. + +--symbolic:: + Usually the object names are output in SHA1 form (with + possible '{caret}' prefix); this option makes them output in a + form as close to the original input as possible. + + +--all:: + Show all refs found in `$GIT_DIR/refs`. + +--branches:: + Show branch refs found in `$GIT_DIR/refs/heads`. + +--tags:: + Show tag refs found in `$GIT_DIR/refs/tags`. + +--remotes:: + Show tag refs found in `$GIT_DIR/refs/remotes`. + +--show-prefix:: + When the command is invoked from a subdirectory, show the + path of the current directory relative to the top-level + directory. + +--show-cdup:: + When the command is invoked from a subdirectory, show the + path of the top-level directory relative to the current + directory (typically a sequence of "../", or an empty string). + +--git-dir:: + Show `$GIT_DIR` if defined else show the path to the .git directory. + +--short, --short=number:: + Instead of outputting the full SHA1 values of object names try to + abbreviate them to a shorter unique name. When no length is specified + 7 is used. The minimum length is 4. + +--since=datestring, --after=datestring:: + Parses the date string, and outputs corresponding + --max-age= parameter for git-rev-list command. + +--until=datestring, --before=datestring:: + Parses the date string, and outputs corresponding + --min-age= parameter for git-rev-list command. + +<args>...:: + Flags and parameters to be parsed. + + +SPECIFYING REVISIONS +-------------------- + +A revision parameter typically, but not necessarily, names a +commit object. They use what is called an 'extended SHA1' +syntax. Here are various ways to spell object names. The +ones listed near the end of this list are to name trees and +blobs contained in a commit. + +* The full SHA1 object name (40-byte hexadecimal string), or + a substring of such that is unique within the repository. + E.g. dae86e1950b1277e545cee180551750029cfe735 and dae86e both + name the same commit object if there are no other object in + your repository whose object name starts with dae86e. + +* An output from `git-describe`; i.e. a closest tag, followed by a + dash, a `g`, and an abbreviated object name. + +* A symbolic ref name. E.g. 'master' typically means the commit + object referenced by $GIT_DIR/refs/heads/master. If you + happen to have both heads/master and tags/master, you can + explicitly say 'heads/master' to tell git which one you mean. + When ambiguous, a `<name>` is disambiguated by taking the + first match in the following rules: + + . if `$GIT_DIR/<name>` exists, that is what you mean (this is usually + useful only for `HEAD`, `FETCH_HEAD` and `MERGE_HEAD`); + + . otherwise, `$GIT_DIR/refs/<name>` if exists; + + . otherwise, `$GIT_DIR/refs/tags/<name>` if exists; + + . otherwise, `$GIT_DIR/refs/heads/<name>` if exists; + + . otherwise, `$GIT_DIR/refs/remotes/<name>` if exists; + + . otherwise, `$GIT_DIR/refs/remotes/<name>/HEAD` if exists. + +* A ref followed by the suffix '@' with a date specification + enclosed in a brace + pair (e.g. '\{yesterday\}', '\{1 month 2 weeks 3 days 1 hour 1 + second ago\}' or '\{1979-02-26 18:30:00\}') to specify the value + of the ref at a prior point in time. This suffix may only be + used immediately following a ref name and the ref must have an + existing log ($GIT_DIR/logs/<ref>). + +* A ref followed by the suffix '@' with an ordinal specification + enclosed in a brace pair (e.g. '\{1\}', '\{15\}') to specify + the n-th prior value of that ref. For example 'master@\{1\}' + is the immediate prior value of 'master' while 'master@\{5\}' + is the 5th prior value of 'master'. This suffix may only be used + immediately following a ref name and the ref must have an existing + log ($GIT_DIR/logs/<ref>). + +* You can use the '@' construct with an empty ref part to get at a + reflog of the current branch. For example, if you are on the + branch 'blabla', then '@\{1\}' means the same as 'blabla@\{1\}'. + +* A suffix '{caret}' to a revision parameter means the first parent of + that commit object. '{caret}<n>' means the <n>th parent (i.e. + 'rev{caret}' + is equivalent to 'rev{caret}1'). As a special rule, + 'rev{caret}0' means the commit itself and is used when 'rev' is the + object name of a tag object that refers to a commit object. + +* A suffix '{tilde}<n>' to a revision parameter means the commit + object that is the <n>th generation grand-parent of the named + commit object, following only the first parent. I.e. rev~3 is + equivalent to rev{caret}{caret}{caret} which is equivalent to + rev{caret}1{caret}1{caret}1. See below for a illustration of + the usage of this form. + +* A suffix '{caret}' followed by an object type name enclosed in + brace pair (e.g. `v0.99.8{caret}\{commit\}`) means the object + could be a tag, and dereference the tag recursively until an + object of that type is found or the object cannot be + dereferenced anymore (in which case, barf). `rev{caret}0` + introduced earlier is a short-hand for `rev{caret}\{commit\}`. + +* A suffix '{caret}' followed by an empty brace pair + (e.g. `v0.99.8{caret}\{\}`) means the object could be a tag, + and dereference the tag recursively until a non-tag object is + found. + +* A colon, followed by a slash, followed by a text: this names + a commit whose commit message starts with the specified text. + This name returns the youngest matching commit which is + reachable from any ref. If the commit message starts with a + '!', you have to repeat that; the special sequence ':/!', + followed by something else than '!' is reserved for now. + +* A suffix ':' followed by a path; this names the blob or tree + at the given path in the tree-ish object named by the part + before the colon. + +* A colon, optionally followed by a stage number (0 to 3) and a + colon, followed by a path; this names a blob object in the + index at the given path. Missing stage number (and the colon + that follows it) names an stage 0 entry. + +Here is an illustration, by Jon Loeliger. Both node B and C are +a commit parents of commit node A. Parent commits are ordered +left-to-right. + + G H I J + \ / \ / + D E F + \ | / \ + \ | / | + \|/ | + B C + \ / + \ / + A + + A = = A^0 + B = A^ = A^1 = A~1 + C = A^2 = A^2 + D = A^^ = A^1^1 = A~2 + E = B^2 = A^^2 + F = B^3 = A^^3 + G = A^^^ = A^1^1^1 = A~3 + H = D^2 = B^^2 = A^^^2 = A~2^2 + I = F^ = B^3^ = A^^3^ + J = F^2 = B^3^2 = A^^3^2 + + +SPECIFYING RANGES +----------------- + +History traversing commands such as `git-log` operate on a set +of commits, not just a single commit. To these commands, +specifying a single revision with the notation described in the +previous section means the set of commits reachable from that +commit, following the commit ancestry chain. + +To exclude commits reachable from a commit, a prefix `{caret}` +notation is used. E.g. "`{caret}r1 r2`" means commits reachable +from `r2` but exclude the ones reachable from `r1`. + +This set operation appears so often that there is a shorthand +for it. "`r1..r2`" is equivalent to "`{caret}r1 r2`". It is +the difference of two sets (subtract the set of commits +reachable from `r1` from the set of commits reachable from +`r2`). + +A similar notation "`r1\...r2`" is called symmetric difference +of `r1` and `r2` and is defined as +"`r1 r2 --not $(git-merge-base --all r1 r2)`". +It is the set of commits that are reachable from either one of +`r1` or `r2` but not from both. + +Two other shorthands for naming a set that is formed by a commit +and its parent commits exists. `r1{caret}@` notation means all +parents of `r1`. `r1{caret}!` includes commit `r1` but excludes +its all parents. + +Here are a handful examples: + + D G H D + D F G H I J D F + ^G D H D + ^D B E I J F B + B...C G H D E B C + ^D B C E I J F B C + C^@ I J F + F^! D G H D F + +Author +------ +Written by Linus Torvalds <torvalds@osdl.org> and +Junio C Hamano <junkio@cox.net> + +Documentation +-------------- +Documentation by Junio C Hamano and the git-list <git@vger.kernel.org>. + +GIT +--- +Part of the gitlink:git[7] suite + |