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NAME | SYNOPSIS | DESCRIPTION | OPTIONS | OUTPUT | BATCH OUTPUT | CAVEATS | GIT | COLOPHON |
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GIT-CAT-FILE(1) Git Manual GIT-CAT-FILE(1)
git-cat-file - Provide contents or details of repository objects
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]
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.
<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.
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.
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.
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.
Part of the git(1) suite
This page is part of the git (Git distributed version control
system) project. Information about the project can be found at
⟨http://git-scm.com/⟩. If you have a bug report for this manual
page, see ⟨http://git-scm.com/community⟩. This page was obtained
from the project's upstream Git repository
⟨https://github.com/git/git.git⟩ on 2025-08-11. (At that time,
the date of the most recent commit that was found in the
repository was 2025-08-07.) If you discover any rendering
problems in this HTML version of the page, or you believe there is
a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
man-pages@man7.org
Git 2.51.0.rc1 2025-08-07 GIT-CAT-FILE(1)
Pages that refer to this page: git(1), git-rev-list(1)
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HTML rendering created 2025-09-06 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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