TP(4) — Silicon Graphics
NAME
tp − magnetic tape format
DESCRIPTION
The command tp(1) dumps files to and extracts files from magtape.
Block zero contains a copy of a stand-alone bootstrap program.
Blocks 1 through 62 contain a directory of the tape. There are 496 entries in the directory; 8 entries per block; 64 bytes per entry. Each entry has the following format:
| struct | tpent { | ||
| char | pathnam[32]; | ||
| short | mode; | ||
| char | uid; | ||
| char | uid; | ||
| char | gid; | ||
| char | spare; | ||
| char | size0; | ||
| short | size2; | ||
| long | time; | ||
| short | tapea; | /∗ tape address ∗/ | |
| short | unused[8]; | ||
| short | cksum; | /∗ check sum ∗/ | |
| } |
The pathnam entry is the path name of the file when put on the tape. If the path name starts with a zero word, the entry is empty. It is at most 32 bytes long and ends in a null byte. Mode, uid, gid, the sizes and time modified are the same as described under i-nodes (fs(4)). The tape address is the tape block number of the start of the contents of the file. Every file starts on a block boundary. The file occupies (size+511)/512 blocks of continuous tape. The checksum entry has a value such that the sum of the 32 words of the directory entry is zero.
Blocks 63 on are available for file storage.
A fake entry has a size of zero. See tp(1).
SEE ALSO
Version 2.3 — July 04, 1985