open.c - 9base - revived minimalist port of Plan 9 userland to Unix | |
git clone git://git.suckless.org/9base | |
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--- | |
open.c (1082B) | |
--- | |
1 #define _GNU_SOURCE /* for Linux O_DIRECT */ | |
2 #include <u.h> | |
3 #define NOPLAN9DEFINES | |
4 #include <sys/file.h> | |
5 #include <libc.h> | |
6 #ifndef O_DIRECT | |
7 #define O_DIRECT 0 | |
8 #endif | |
9 | |
10 int | |
11 p9open(char *name, int mode) | |
12 { | |
13 int cexec, rclose; | |
14 int fd, umode, lock, rdwr; | |
15 struct flock fl; | |
16 | |
17 rdwr = mode&3; | |
18 umode = rdwr; | |
19 cexec = mode&OCEXEC; | |
20 rclose = mode&ORCLOSE; | |
21 lock = mode&OLOCK; | |
22 mode &= ~(3|OCEXEC|ORCLOSE|OLOCK); | |
23 if(mode&OTRUNC){ | |
24 umode |= O_TRUNC; | |
25 mode ^= OTRUNC; | |
26 } | |
27 if(mode&ODIRECT){ | |
28 umode |= O_DIRECT; | |
29 mode ^= ODIRECT; | |
30 } | |
31 if(mode&ONONBLOCK){ | |
32 umode |= O_NONBLOCK; | |
33 mode ^= ONONBLOCK; | |
34 } | |
35 if(mode&OAPPEND){ | |
36 umode |= O_APPEND; | |
37 mode ^= OAPPEND; | |
38 } | |
39 if(mode){ | |
40 werrstr("mode 0x%x not supported", mode); | |
41 return -1; | |
42 } | |
43 fd = open(name, umode); | |
44 if(fd >= 0){ | |
45 if(lock){ | |
46 fl.l_type = (rdwr==OREAD) ? F_RDLCK : F_WRLCK; | |
47 fl.l_whence = SEEK_SET; | |
48 fl.l_start = 0; | |
49 fl.l_len = 0; | |
50 if(fcntl(fd, F_SETLK, &fl) < 0){ | |
51 close(fd); | |
52 werrstr("lock: %r"); | |
53 return -1; | |
54 } | |
55 } | |
56 if(cexec) | |
57 fcntl(fd, F_SETFL, FD_CLOEXEC); | |
58 if(rclose) | |
59 remove(name); | |
60 } | |
61 return fd; | |
62 } |