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diff --git a/Documentation/git-cat-file.txt b/Documentation/git-cat-file.txt new file mode 100644 index 0000000..bd95a6c --- /dev/null +++ b/Documentation/git-cat-file.txt @@ -0,0 +1,412 @@ +git-cat-file(1) +=============== + +NAME +---- +git-cat-file - Provide contents or details of repository objects + +SYNOPSIS +-------- +[verse] +'git cat-file' <type> <object> +'git cat-file' (-e | -p) <object> +'git cat-file' (-t | -s) [--allow-unknown-type] <object> +'git cat-file' (--textconv | --filters) + [<rev>:<path|tree-ish> | --path=<path|tree-ish> <rev>] +'git cat-file' (--batch | --batch-check | --batch-command) [--batch-all-objects] + [--buffer] [--follow-symlinks] [--unordered] + [--textconv | --filters] [-Z] + +DESCRIPTION +----------- +Output the contents or other properties such as size, type or delta +information of one or more objects. + +This command can operate in two modes, depending on whether an option +from the `--batch` family is specified. + +In non-batch mode, the command provides information on an object +named on the command line. + +In batch mode, arguments are read from standard input. + +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>`. If used with `--use-mailmap` option, will show + the size of updated object after replacing idents using the + mailmap mechanism. + +-e:: + Exit with zero status if `<object>` exists and is a valid + object. If `<object>` is of an invalid format, exit with non-zero + status and emit 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. + +--[no-]mailmap:: +--[no-]use-mailmap:: + Use mailmap file to map author, committer and tagger names + and email addresses to canonical real names and email addresses. + See linkgit:git-shortlog[1]. + +--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`, `--filters`, or `--use-mailmap`. ++ +-- + * When used with `--textconv` or `--filters`, the input lines + must specify the path, separated by whitespace. See the section + `BATCH OUTPUT` below for details. + + * When used with `--use-mailmap`, for commit and tag objects, the + contents part of the output shows the identities replaced using the + mailmap mechanism, while the information part of the output shows + the size of the object as if it actually recorded the replacement + identities. +-- + +--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`, `--filters` + or `--use-mailmap`. ++ +-- + * When used with `--textconv` or `--filters`, the input lines must + specify the path, separated by whitespace. See the section + `BATCH OUTPUT` below for details. + + * When used with `--use-mailmap`, for commit and tag objects, the + printed object information shows the size of the object as if the + identities recorded in it were replaced by the mailmap mechanism. +-- + +--batch-command:: +--batch-command=<format>:: + Enter a command mode that reads commands and arguments from stdin. May + only be combined with `--buffer`, `--textconv`, `--use-mailmap` or + `--filters`. ++ +-- + * When used with `--textconv` or `--filters`, the input lines must + specify the path, separated by whitespace. See the section + `BATCH OUTPUT` below for details. + + * When used with `--use-mailmap`, for commit and tag objects, the + `contents` command shows the identities replaced using the + mailmap mechanism, while the `info` command shows the size + of the object as if it actually recorded the replacement + identities. +-- ++ +`--batch-command` recognizes the following commands: ++ +-- +contents <object>:: + Print object contents for object reference `<object>`. This corresponds to + the output of `--batch`. + +info <object>:: + Print object info for object reference `<object>`. This corresponds to the + output of `--batch-check`. + +flush:: + Used with `--buffer` to execute all preceding commands that were issued + since the beginning or since the last flush was issued. When `--buffer` + is used, no output will come until a `flush` is issued. When `--buffer` + is not used, commands are flushed each time without issuing `flush`. +-- ++ + +--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. By default, + the objects are visited in order sorted by their hashes; see + also `--unordered` below. Objects are presented as-is, without + respecting the "replace" mechanism of linkgit:git-replace[1]. + +--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` or `--batch-command` 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 +-- + +-Z:: + Only meaningful with `--batch`, `--batch-check`, or + `--batch-command`; input and output is NUL-delimited instead of + newline-delimited. + +-z:: + Only meaningful with `--batch`, `--batch-check`, or + `--batch-command`; input is NUL-delimited instead of + newline-delimited. This option is deprecated in favor of + `-Z` as the output can otherwise be ambiguous. + + +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]. + +When `--batch-command` is given, `cat-file` will read commands from stdin, +one per line, and print information based on the command given. With +`--batch-command`, the `info` command followed by an object will print +information about the object the same way `--batch-check` would, and the +`contents` command followed by an object prints contents in the same way +`--batch` would. + +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 full hex representation of the object name. + +`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 + full hex representation of the delta base object name. + Otherwise, expands to the null OID (all 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, or if `--batch-command` is used with the `contents` +command, 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: + +------------ +<oid> SP <type> SP <size> LF +<contents> LF +------------ + +Whereas `--batch-check='%(objectname) %(objecttype)'` would produce: + +------------ +<oid> 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. + +Alternatively, when `-Z` is passed, the line feeds in any of the above examples +are replaced with NUL terminators. This ensures that output will be parsable if +the output itself would contain a linefeed and is thus recommended for +scripting purposes. + +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 |