A function letter does not need to be prefixed with a dash ("-"), and may be combined with other single-letter options.A long function name must be prefixed with a double dash ("--").For example, the following commands are all equivalent: Use the archive's suffix to determine the compression program.For example, if this option is specified, an archive with the extension gz will always be handled as if the --gzip option had been specified (see --gzip, below).Causes tar to exclude all directories that contain a cache directory tag.
The first argument to tar should be a function specification: either one of the letters A, c, d, r, t, u, or x, or one of the long function names.Some options take a parameter; with the single-letter form these must be given as separate arguments.With the long form, they may be given by appending "=value" to the option.About tar tar syntax tar examples Related commands Linux and Unix main page The tar program is used to create, maintain, modify, and extract files that are archived in the tar format. It was later formalized as part of the POSIX standard, and today is used to collect, distribute, and archive files, while preserving file system attributes such as user and group permissions, access and modification dates, and directory structures. tar was originally developed in the early days of Unix for the purpose of backing up files to tape-based storage devices.
With other operations, this option informs tar that the archive is in incremental format. Normally an entire block of bytes with a value of zero indicates an end-of-archive; this option helps tar handle a damaged archive, or any other oddly-formed archive with blocks of zeros in its contents. Use this option if you are not happy with the compression program associated with the suffix at compile time, or if you have a compression program that GNU tar does not support.