1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
|
/*
* Written and released to the public domain by David Engel.
*
* This function attempts to open a file which may be in any of
* several directories. It is particularly useful for opening
* configuration files. For example, PROG.EXE can easily open
* PROG.CFG (which is kept in the same directory) by executing:
*
* cfg_file = pfopen("PROG.CFG", "r", getenv("PATH"));
*
* NULL is returned if the file can't be opened.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifdef unix
#define SEP_CHARS ":"
#else
#define SEP_CHARS ";"
#endif
FILE *pfopen(const char *name, const char *mode, const char *dirs)
{
char *ptr;
char *tdirs;
FILE *file = NULL;
if (dirs == NULL || dirs[0] == '\0')
return NULL;
if ((tdirs = malloc(strlen(dirs)+1)) == NULL)
return NULL;
strcpy(tdirs, dirs);
for (ptr = strtok(tdirs, SEP_CHARS); file == NULL && ptr != NULL;
ptr = strtok(NULL, SEP_CHARS))
{
size_t len;
char work[FILENAME_MAX];
strcpy(work, ptr);
len = strlen(work);
if (len && work[len-1] != '/' && work[len-1] != '\\')
strcat(work, "/");
strcat(work, name);
file = fopen(work, mode);
}
free(tdirs);
return file;
}
#ifdef TEST
int main(int argc, char **argv)
{
FILE *file;
if (argc != 4)
{
fprintf(stderr, "usage: pfopen name mode dirs\n");
exit(1);
}
file = pfopen(argv[1], argv[2], argv[3]);
printf("%s \"%s\" with mode \"%s\"\n", (file == NULL) ?
"Could not open" : "Opened", argv[1], argv[2]);
return 0;
}
#endif
|
