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].

Instead of the content, show the object type identified by <object>.

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.

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.

Pretty-print the contents of <object> based on its 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.

Use mailmap file to map author, committer and tagger names and email addresses to canonical real names and email addresses. See git-shortlog[1].

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>.

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>.

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.

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.

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.

Enter a command mode that reads commands and arguments from stdin. May only be combined with --buffer, --textconv, --use-mailmap or --filters.

--batch-command recognizes the following commands:

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].

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.

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 -s or -t to query broken/corrupt objects of unknown type.

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

Only meaningful with --batch, --batch-check, or --batch-command; input and output is NUL-delimited instead of newline-delimited.

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.

The full hex representation of the object name.

The type of the object (the same as cat-file -t reports).

The size, in bytes, of the object (the same as cat-file -s reports).

The size, in bytes, that the object takes up on disk. See the note about on-disk sizes in the CAVEATS section below.

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.

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.