Git Cat-File Command Output Formatting and Caveats

-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 `--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

The git-cat-file command provides various options for customizing its output, including handling of symlinks, ambiguous object names, and error messages, while also noting important caveats regarding on-disk object sizes and potential inconsistencies in the object database.