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diff --git a/Documentation/git-cat-file.txt b/Documentation/git-cat-file.txt new file mode 100644 index 000000000000..8eca671b8278 --- /dev/null +++ b/Documentation/git-cat-file.txt @@ -0,0 +1,319 @@ +git-cat-file(1) +=============== + +NAME +---- +git-cat-file - Provide content or type and size information for repository objects + + +SYNOPSIS +-------- +[verse] +'git cat-file' (-t [--allow-unknown-type]| -s [--allow-unknown-type]| -e | -p | <type> | --textconv | --filters ) [--path=<path>] <object> +'git cat-file' (--batch | --batch-check) [ --textconv | --filters ] [--follow-symlinks] + +DESCRIPTION +----------- +In its first form, the command provides the content or the type of an object in +the repository. The type is required unless `-t` or `-p` is used to find the +object type, or `-s` is used to find the object size, or `--textconv` or +`--filters` is used (which imply type "blob"). + +In the second form, a list of objects (separated by linefeeds) is provided on +stdin, and the SHA-1, type, and size of each object is printed on stdout. The +output format can be overridden using the optional `<format>` argument. If +either `--textconv` or `--filters` was specified, the input is expected to +list the object names followed by the path name, separated by a single +whitespace, so that the appropriate drivers can be determined. + +OPTIONS +------- +<object>:: + The name of the object to show. + For a more complete list of ways to spell object names, see + the "SPECIFYING REVISIONS" section in linkgit:gitrevisions[7]. + +-t:: + Instead of the content, show the object type identified by + <object>. + +-s:: + Instead of the content, show the object size identified by + <object>. + +-e:: + Exit with zero status if <object> exists and is a valid + object. If <object> is of an invalid format exit with non-zero and + emits an error on stderr. + +-p:: + Pretty-print the contents of <object> based on its type. + +<type>:: + Typically this matches the real type of <object> but asking + for a type that can trivially be dereferenced from the given + <object> is also permitted. An example is to ask for a + "tree" with <object> being a commit object that contains it, + or to ask for a "blob" with <object> being a tag object that + points at it. + +--textconv:: + Show the content as transformed by a textconv filter. In this case, + <object> has to be of the form <tree-ish>:<path>, or :<path> in + order to apply the filter to the content recorded in the index at + <path>. + +--filters:: + Show the content as converted by the filters configured in + the current working tree for the given <path> (i.e. smudge filters, + end-of-line conversion, etc). In this case, <object> has to be of + the form <tree-ish>:<path>, or :<path>. + +--path=<path>:: + For use with --textconv or --filters, to allow specifying an object + name and a path separately, e.g. when it is difficult to figure out + the revision from which the blob came. + +--batch:: +--batch=<format>:: + Print object information and contents for each object provided + on stdin. May not be combined with any other options or arguments + except `--textconv` or `--filters`, in which case the input lines + also need to specify the path, separated by whitespace. See the + section `BATCH OUTPUT` below for details. + +--batch-check:: +--batch-check=<format>:: + Print object information for each object provided on stdin. May + not be combined with any other options or arguments except + `--textconv` or `--filters`, in which case the input lines also + need to specify the path, separated by whitespace. See the + section `BATCH OUTPUT` below for details. + +--batch-all-objects:: + Instead of reading a list of objects on stdin, perform the + requested batch operation on all objects in the repository and + any alternate object stores (not just reachable objects). + Requires `--batch` or `--batch-check` be specified. Note that + the objects are visited in order sorted by their hashes. + +--buffer:: + Normally batch output is flushed after each object is output, so + that a process can interactively read and write from + `cat-file`. With this option, the output uses normal stdio + buffering; this is much more efficient when invoking + `--batch-check` on a large number of objects. + +--unordered:: + When `--batch-all-objects` is in use, visit objects in an + order which may be more efficient for accessing the object + contents than hash order. The exact details of the order are + unspecified, but if you do not require a specific order, this + should generally result in faster output, especially with + `--batch`. Note that `cat-file` will still show each object + only once, even if it is stored multiple times in the + repository. + +--allow-unknown-type:: + Allow -s or -t to query broken/corrupt objects of unknown type. + +--follow-symlinks:: + With --batch or --batch-check, follow symlinks inside the + repository when requesting objects with extended SHA-1 + expressions of the form tree-ish:path-in-tree. Instead of + providing output about the link itself, provide output about + the linked-to object. If a symlink points outside the + tree-ish (e.g. a link to /foo or a root-level link to ../foo), + the portion of the link which is outside the tree will be + printed. ++ +This option does not (currently) work correctly when an object in the +index is specified (e.g. `:link` instead of `HEAD:link`) rather than +one in the tree. ++ +This option cannot (currently) be used unless `--batch` or +`--batch-check` is used. ++ +For example, consider a git repository containing: ++ +-- + f: a file containing "hello\n" + link: a symlink to f + dir/link: a symlink to ../f + plink: a symlink to ../f + alink: a symlink to /etc/passwd +-- ++ +For a regular file `f`, `echo HEAD:f | git cat-file --batch` would print ++ +-- + ce013625030ba8dba906f756967f9e9ca394464a blob 6 +-- ++ +And `echo HEAD:link | git cat-file --batch --follow-symlinks` would +print the same thing, as would `HEAD:dir/link`, as they both point at +`HEAD:f`. ++ +Without `--follow-symlinks`, these would print data about the symlink +itself. In the case of `HEAD:link`, you would see ++ +-- + 4d1ae35ba2c8ec712fa2a379db44ad639ca277bd blob 1 +-- ++ +Both `plink` and `alink` point outside the tree, so they would +respectively print: ++ +-- + symlink 4 + ../f + + symlink 11 + /etc/passwd +-- + + +OUTPUT +------ +If `-t` is specified, one of the <type>. + +If `-s` is specified, the size of the <object> in bytes. + +If `-e` is specified, no output, unless the <object> is malformed. + +If `-p` is specified, the contents of <object> are pretty-printed. + +If <type> is specified, the raw (though uncompressed) contents of the <object> +will be returned. + +BATCH OUTPUT +------------ + +If `--batch` or `--batch-check` is given, `cat-file` will read objects +from stdin, one per line, and print information about them. By default, +the whole line is considered as an object, as if it were fed to +linkgit:git-rev-parse[1]. + +You can specify the information shown for each object by using a custom +`<format>`. The `<format>` is copied literally to stdout for each +object, with placeholders of the form `%(atom)` expanded, followed by a +newline. The available atoms are: + +`objectname`:: + The 40-hex object name of the object. + +`objecttype`:: + The type of the object (the same as `cat-file -t` reports). + +`objectsize`:: + The size, in bytes, of the object (the same as `cat-file -s` + reports). + +`objectsize:disk`:: + The size, in bytes, that the object takes up on disk. See the + note about on-disk sizes in the `CAVEATS` section below. + +`deltabase`:: + If the object is stored as a delta on-disk, this expands to the + 40-hex sha1 of the delta base object. Otherwise, expands to the + null sha1 (40 zeroes). See `CAVEATS` below. + +`rest`:: + If this atom is used in the output string, input lines are split + at the first whitespace boundary. All characters before that + whitespace are considered to be the object name; characters + after that first run of whitespace (i.e., the "rest" of the + line) are output in place of the `%(rest)` atom. + +If no format is specified, the default format is `%(objectname) +%(objecttype) %(objectsize)`. + +If `--batch` is specified, the object information is followed by the +object contents (consisting of `%(objectsize)` bytes), followed by a +newline. + +For example, `--batch` without a custom format would produce: + +------------ +<sha1> SP <type> SP <size> LF +<contents> LF +------------ + +Whereas `--batch-check='%(objectname) %(objecttype)'` would produce: + +------------ +<sha1> SP <type> LF +------------ + +If a name is specified on stdin that cannot be resolved to an object in +the repository, then `cat-file` will ignore any custom format and print: + +------------ +<object> SP missing LF +------------ + +If a name is specified that might refer to more than one object (an ambiguous short sha), then `cat-file` will ignore any custom format and print: + +------------ +<object> SP ambiguous LF +------------ + +If --follow-symlinks is used, and a symlink in the repository points +outside the repository, then `cat-file` will ignore any custom format +and print: + +------------ +symlink SP <size> LF +<symlink> LF +------------ + +The symlink will either be absolute (beginning with a /), or relative +to the tree root. For instance, if dir/link points to ../../foo, then +<symlink> will be ../foo. <size> is the size of the symlink in bytes. + +If --follow-symlinks is used, the following error messages will be +displayed: + +------------ +<object> SP missing LF +------------ +is printed when the initial symlink requested does not exist. + +------------ +dangling SP <size> LF +<object> LF +------------ +is printed when the initial symlink exists, but something that +it (transitive-of) points to does not. + +------------ +loop SP <size> LF +<object> LF +------------ +is printed for symlink loops (or any symlinks that +require more than 40 link resolutions to resolve). + +------------ +notdir SP <size> LF +<object> LF +------------ +is printed when, during symlink resolution, a file is used as a +directory name. + +CAVEATS +------- + +Note that the sizes of objects on disk are reported accurately, but care +should be taken in drawing conclusions about which refs or objects are +responsible for disk usage. The size of a packed non-delta object may be +much larger than the size of objects which delta against it, but the +choice of which object is the base and which is the delta is arbitrary +and is subject to change during a repack. + +Note also that multiple copies of an object may be present in the object +database; in this case, it is undefined which copy's size or delta base +will be reported. + +GIT +--- +Part of the linkgit:git[1] suite |