# git-cat-file

## NAME



           git-cat-file - Provide contents or details of repository objects
    


## SYNOPSIS



           _git cat-file_ <type> <object>
           _git cat-file_ (-e | -p | -t | -s) <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 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 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>_.
    
           --filter=<filter-spec>, --no-filter
               Omit objects from the list of printed objects. This can only
               be used in combination with one of the batched modes. Excluded
               objects that have been explicitly requested via any of the
               batch modes that read objects via standard input (**--batch** ,
               **--batch-check**) will be reported as "filtered". Excluded
               objects in **--batch-all-objects** mode will not be printed at
               all. The _< filter-spec>_ may be one of the following:
    
               The form _--filter=blob:none_ omits all blobs.
    
               The form _--filter=blob:limit= <n>[kmg]_ omits blobs of size at
               least n bytes or units. n may be zero. The suffixes k, m, and
               g can be used to name units in KiB, MiB, or GiB. For example,
               _blob:limit=1k_ is the same as _blob:limit=1024_.
    
               The form _--filter=object:type=(tag|commit|tree|blob)_ omits all
               objects which are not of the requested type.
    
           --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 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.
    
           --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 in the
           same order as they have been read. By default, the whole line is
           considered as an object, as if it were fed to 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).
    
           **objectmode**
               If the specified object has mode information (such as a tree
               or index entry), the mode expressed as an octal integer.
               Otherwise, empty string.
    
           **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 on stdin that is filtered out via
           **--filter=** , then **cat-file** will ignore any custom format and print:
    
               <object> SP excluded 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 a name is specified that refers to a submodule entry in a tree
           and the target object does not exist in the repository, then
           **cat-file** will ignore any custom format and print (with the object
           ID of the submodule):
    
               <oid> SP submodule 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 git(1) suite
    


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