Commit | Line | Data |
---|---|---|
2b64e55a | 1 | .\" @(#)tp5.5 5.1 (Berkeley) %G% |
75ba5eea | 2 | .\" |
2b64e55a | 3 | .TH TP 5 "15 January 1983" |
75ba5eea KM |
4 | .AT 3 |
5 | .SH NAME | |
6 | tp \- DEC/mag tape formats | |
7 | .SH DESCRIPTION | |
8 | .I Tp | |
9 | dumps files to and extracts files from | |
10 | DECtape and magtape. | |
11 | The formats of these tapes are the same except | |
12 | that magtapes have larger directories. | |
13 | .PP | |
14 | Block zero contains a | |
15 | copy of a stand-alone bootstrap program. | |
16 | See | |
17 | .IR reboot (8). | |
18 | .PP | |
19 | Blocks 1 through 24 | |
20 | for DECtape (1 through 62 for magtape) | |
21 | contain a directory of the tape. | |
22 | There are 192 (resp. 496) entries in the directory; | |
23 | 8 entries per block; | |
24 | 64 bytes per entry. | |
25 | Each entry has the following format: | |
26 | .nf | |
27 | .IP "" | |
28 | .ta 8n +\w'unsigned short 'u | |
29 | struct { | |
30 | char pathname[32]; | |
31 | unsigned short mode; | |
32 | char uid; | |
33 | char gid; | |
34 | char unused1; | |
35 | char size[3]; | |
36 | long modtime; | |
37 | unsigned short tapeaddr; | |
38 | char unused2[16]; | |
39 | unsigned short checksum; | |
40 | }; | |
41 | .fi | |
42 | .DT | |
43 | .PP | |
44 | The path name entry is the path name of the | |
45 | file when put on the tape. | |
46 | If the pathname starts with a zero word, | |
47 | the entry is empty. | |
48 | It is at most 32 bytes long and ends in a null byte. | |
49 | Mode, uid, gid, size and time modified | |
50 | are the same as described under i-nodes | |
51 | (see file system | |
2b64e55a | 52 | .IR fs (5)). |
75ba5eea KM |
53 | The tape address is the tape block number of the start of |
54 | the contents of the file. | |
55 | Every file | |
56 | starts on a block boundary. | |
57 | The file occupies (size+511)/512 blocks | |
58 | of continuous tape. | |
59 | The checksum entry has a value such that | |
60 | the sum of the 32 words of the directory entry is zero. | |
61 | .PP | |
62 | Blocks above 25 (resp. 63) are available for file storage. | |
63 | .PP | |
64 | A fake entry | |
65 | has a size of zero. | |
66 | .SH "SEE ALSO" | |
2b64e55a | 67 | fs(5), tp(1) |
75ba5eea KM |
68 | .SH BUGS |
69 | The | |
70 | .I pathname, uid, gid, | |
71 | and | |
72 | .I size | |
73 | fields are too small. |