1TP(5) File Formats Manual TP(5)
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6 tp - DEC/mag tape formats
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9 The command tp dumps files to and extracts files from DECtape and mag‐
10 tape. The formats of these tapes are the same except that magtapes
11 have larger directories.
12 Block zero contains a copy of a stand-alone bootstrap program. See
14 bproc(8).
15 Blocks 1 through 24 for DECtape (1 through 62 for magtape) contain a
17 directory of the tape. There are 192 (resp. 496) entries in the direc‐
18 tory; 8 entries per block; 64 bytes per entry. Each entry has the fol‐
19 lowing format:
20 struct {
22 char pathname[32];
23 int mode;
24 char uid;
25 char gid;
26 char unused1;
27 char size[3];
28 long modtime;
29 int tapeaddr;
30 char unused2[16];
31 int checksum;
32 };
33 The path name entry is the path name of the file when put on the tape.
35 If the pathname starts with a zero word, the entry is empty. It is at
36 most 32 bytes long and ends in a null byte. Mode, uid, gid, size and
37 time modified are the same as described under i-nodes (see file system
38 filsys(5)). The tape address is the tape block number of the start of
39 the contents of the file. Every file starts on a block boundary. The
40 file occupies (size+511)/512 blocks of continuous tape. The checksum
41 entry has a value such that the sum of the 32 words of the directory
42 entry is zero.
43 Blocks above 25 (resp. 63) are available for file storage.
45 A fake entry has a size of zero.
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49 filsys(5), tp(1)
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52 The pathname, uid, gid, and size fields are too small.
53 TP(5)