lemon-project-template-glpk
view deps/glpk/src/zlib/zio.c @ 9:33de93886c88
Import GLPK 4.47
| author | Alpar Juttner <alpar@cs.elte.hu> |
|---|---|
| date | Sun, 06 Nov 2011 20:59:10 +0100 |
| parents | |
| children |
line source
1 /* zio.c (simulation of non-standard low-level i/o functions) */
3 /* Written by Andrew Makhorin <mao@gnu.org>, April 2011
4 * For conditions of distribution and use, see copyright notice in
5 * zlib.h */
7 /* (reserved for copyright notice) */
9 #include <assert.h>
10 #include <stdio.h>
11 #include "zio.h"
13 static FILE *file[FOPEN_MAX];
14 static int initialized = 0;
16 static void initialize(void)
17 { int fd;
18 assert(!initialized);
19 file[0] = stdin;
20 file[1] = stdout;
21 file[2] = stderr;
22 for (fd = 3; fd < FOPEN_MAX; fd++)
23 file[fd] = NULL;
24 initialized = 1;
25 return;
26 }
28 int open(const char *path, int oflag, ...)
29 { FILE *fp;
30 int fd;
31 if (!initialized) initialize();
32 /* see file gzlib.c, function gz_open */
33 if (oflag == O_RDONLY)
34 fp = fopen(path, "rb");
35 else if (oflag == (O_WRONLY | O_CREAT | O_TRUNC))
36 fp = fopen(path, "wb");
37 else if (oflag == (O_WRONLY | O_CREAT | O_APPEND))
38 fp = fopen(path, "ab");
39 else
40 assert(oflag != oflag);
41 if (fp == NULL)
42 return -1;
43 for (fd = 0; fd < FOPEN_MAX; fd++)
44 if (file[fd] == NULL) break;
45 assert(fd < FOPEN_MAX);
46 file[fd] = fp;
47 return fd;
48 }
50 long read(int fd, void *buf, unsigned long nbyte)
51 { unsigned long count;
52 if (!initialized) initialize();
53 assert(0 <= fd && fd < FOPEN_MAX);
54 assert(file[fd] != NULL);
55 count = fread(buf, 1, nbyte, file[fd]);
56 if (ferror(file[fd]))
57 return -1;
58 return count;
59 }
61 long write(int fd, const void *buf, unsigned long nbyte)
62 { unsigned long count;
63 if (!initialized) initialize();
64 assert(0 <= fd && fd < FOPEN_MAX);
65 assert(file[fd] != NULL);
66 count = fwrite(buf, 1, nbyte, file[fd]);
67 if (count != nbyte)
68 return -1;
69 if (fflush(file[fd]) != 0)
70 return -1;
71 return count;
72 }
74 long lseek(int fd, long offset, int whence)
75 { if (!initialized) initialize();
76 assert(0 <= fd && fd < FOPEN_MAX);
77 assert(file[fd] != NULL);
78 if (fseek(file[fd], offset, whence) != 0)
79 return -1;
80 return ftell(file[fd]);
81 }
83 int close(int fd)
84 { if (!initialized) initialize();
85 assert(0 <= fd && fd < FOPEN_MAX);
86 assert(file[fd] != NULL);
87 fclose(file[fd]);
88 file[fd] = NULL;
89 return 0;
90 }
92 /* eof */