<Tr> <Th> Standard </Th> <Td> POSIX since POSIX. 1, presently in the definition of pax (1) </Td> </Tr> <Tr> <Th> Open format? </Th> <Td> Yes </Td> </Tr> <P> In computing, tar is a computer software utility for collecting many files into one archive file, often referred to as a tarball, for distribution or backup purposes . The name is derived from (t) ape (ar) chive, as it was originally developed to write data to sequential I / O devices with no file system of their own . The archive data sets created by tar contain various file system parameters, such as name, time stamps, ownership, file access permissions, and directory organization . The command line utility was first introduced in the seventh edition of unix (v7) in January 1979, replacing the tp program . The file structure to store this information was later standardized in POSIX. 1 - 1988 and later POSIX. 1 - 2001 and became a format supported by most modern file archiving systems . </P> <P> Many historic tape drives read and write variable - length data blocks, leaving significant wasted space on the tape between blocks (for the tape to physically start and stop moving). Some tape drives (and raw disks) only support fixed - length data blocks . Also, when writing to any medium such as a filesystem or network, it takes less time to write one large block than many small blocks . Therefore, the tar command writes data in blocks of many 512 byte records . The user can specify a blocking factor, which is the number of records per block; the default is 20, producing 10 kilobyte blocks . </P>

Which is the primary purpose of using the tar command