projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| 1bd0b214 BJ |
1 | /* Copyright (c) 1979 Regents of the University of California */ |
| 2 | #include <stdio.h> | |
| 3 | ||
| 4 | /* | |
| 5 | * Seek for standard library. Coordinates with buffering. | |
| 6 | */ | |
| 7 | ||
| 8 | long fseek(iop, offset, ptrname) | |
| 9 | register FILE *iop; | |
| 10 | long offset; | |
| 11 | { | |
| 12 | register n, resync; | |
| 13 | ||
| 14 | if (iop->_flag&_IODIRT) { | |
| 15 | fflush(iop); | |
| 16 | return(lseek(fileno(iop), offset, ptrname)); | |
| 17 | } | |
| 18 | if (iop->_flag&(_IOREAD|_IOWRT)) { | |
| 19 | resync = 0; | |
| 20 | if (ptrname==1) { /* relative */ | |
| 21 | n = iop->_cnt; | |
| 22 | if (n<0) | |
| 23 | n = 0; | |
| 24 | } else { | |
| 25 | n = offset&01; | |
| 26 | resync = n; | |
| 27 | } | |
| 28 | n = lseek(fileno(iop), offset - n, ptrname); | |
| 29 | iop->_cnt = 0; | |
| 30 | iop->_ptr = iop->_base ; | |
| 31 | iop->_delta = 0; | |
| 32 | if (resync) | |
| 33 | getc(iop); | |
| 34 | return(n); | |
| 35 | } | |
| 36 | _error("fseek\n"); | |
| 37 | } | |
| 38 | ||
| 39 | /* The current character is always iop->_cnt characters behind the current | |
| 40 | position in the file, except when a file is open and in use for pure writing | |
| 41 | in which case it is _IODIRT(y), and will be correctly positioned by fflush */ |