projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| 586c39b1 DF |
1 | /* |
| 2 | * Copyright (c) 1980 Regents of the University of California. | |
| 3 | * All rights reserved. The Berkeley software License Agreement | |
| 4 | * specifies the terms and conditions for redistribution. | |
| 5 | */ | |
| 6 | ||
| 7 | #ifndef lint | |
| 8 | static char sccsid[] = "@(#)freopen.c 5.1 (Berkeley) %G%"; | |
| 9 | #endif not lint | |
| 10 | ||
| 41e01b3e S |
11 | #include <sys/types.h> |
| 12 | #include <sys/file.h> | |
| 13 | #include <stdio.h> | |
| 2de31004 BJ |
14 | |
| 15 | FILE * | |
| 16 | freopen(file, mode, iop) | |
| 41e01b3e S |
17 | char *file; |
| 18 | register char *mode; | |
| 19 | register FILE *iop; | |
| 2de31004 | 20 | { |
| 41e01b3e | 21 | register f, rw, oflags; |
| d8af6b8b | 22 | |
| 41e01b3e | 23 | rw = (mode[1] == '+'); |
| 2de31004 BJ |
24 | |
| 25 | fclose(iop); | |
| 41e01b3e S |
26 | |
| 27 | switch (*mode) { | |
| 28 | case 'a': | |
| 29 | oflags = O_CREAT | (rw ? O_RDWR : O_WRONLY); | |
| 30 | break; | |
| 31 | case 'r': | |
| 32 | oflags = rw ? O_RDWR : O_RDONLY; | |
| 33 | break; | |
| 34 | case 'w': | |
| 35 | oflags = O_TRUNC | O_CREAT | (rw ? O_RDWR : O_WRONLY); | |
| 36 | break; | |
| 37 | default: | |
| 38 | return (NULL); | |
| 39 | } | |
| 40 | ||
| 41 | f = open(file, oflags, 0666); | |
| 2de31004 | 42 | if (f < 0) |
| 41e01b3e S |
43 | return (NULL); |
| 44 | ||
| 45 | if (*mode == 'a') | |
| 46 | lseek(f, (off_t)0, L_XTND); | |
| 47 | ||
| d8af6b8b | 48 | iop->_cnt = 0; |
| 2de31004 | 49 | iop->_file = f; |
| 41e01b3e | 50 | iop->_bufsiz = 0; |
| d8af6b8b | 51 | if (rw) |
| 41e01b3e S |
52 | iop->_flag = _IORW; |
| 53 | else if (*mode == 'r') | |
| 54 | iop->_flag = _IOREAD; | |
| 2de31004 | 55 | else |
| 41e01b3e S |
56 | iop->_flag = _IOWRT; |
| 57 | iop->_base = iop->_ptr = NULL; | |
| 58 | return (iop); | |
| 2de31004 | 59 | } |