git cat-file (-t | -s | -e | -p | <type> | --textconv ) <object> git cat-file (--batch | --batch-check) < <list-of-objects>
In its first form, the command provides the content or the type of an object in the repository. The type is required unless -t or -p is used to find the object type, or -s is used to find the object size, or --textconv is used (which implies type "blob").
In the second form, a list of objects (separated by linefeeds) is provided on stdin, and the SHA-1, type, and size of each object is printed on stdout.
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.
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. By default, the whole line is considered as an object, as if it were fed to git-rev-parse(1).
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:
If no format is specified, the default format is %(objectname) %(objecttype) %(objectsize).
If --batch is specified, 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:
<sha1> SP <type> SP <size> LF <contents> LF
Whereas --batch-check='%(objectname) %(objecttype)' would produce:
<sha1> 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
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