git-cat-file(1) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | OUTPUT | BATCH OUTPUT | CAVEATS | GIT | COLOPHON

GIT-CAT-FILE(1)                Git Manual                GIT-CAT-FILE(1)

NAME         top

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

SYNOPSIS         top

       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         top

       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         top

       <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>.

       --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.

       --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         top

       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         top

       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 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         top

       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         top

       Part of the git(1) suite

COLOPHON         top

       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 2023-12-22.  (At that time,
       the date of the most recent commit that was found in the
       repository was 2023-12-20.)  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 2.43.0.174.g055bb6         2023-12-20                GIT-CAT-FILE(1)

Pages that refer to this page: git(1)git-rev-list(1)