| 1 |
#ifndef lint |
| 2 |
static const char RCSid[] = "$Id: paths.c,v 2.4 2003/07/01 21:21:40 greg Exp $"; |
| 3 |
#endif |
| 4 |
/* |
| 5 |
* Find a writeable tempfile directory. |
| 6 |
* Create unique filenames therein, and possibly open the file. |
| 7 |
* |
| 8 |
*/ |
| 9 |
|
| 10 |
#include "copyright.h" |
| 11 |
|
| 12 |
#include "paths.h" |
| 13 |
|
| 14 |
|
| 15 |
#define TEMPFILE_TEMPLATE "rtXXXXXX" |
| 16 |
static const char *defaultpaths[] = DEFAULT_TEMPDIRS; |
| 17 |
|
| 18 |
|
| 19 |
/* Return a writeable directory for temporary files */ |
| 20 |
/* If s is NULL, we return a static string */ |
| 21 |
char * |
| 22 |
temp_directory(char *s, size_t len) |
| 23 |
{ |
| 24 |
static char td[PATH_MAX]; /* remember */ |
| 25 |
char * ts = NULL; |
| 26 |
int i = 0; |
| 27 |
|
| 28 |
if (td[0] != '\0') { /* we already have one */ |
| 29 |
if (s == NULL) { return td; } |
| 30 |
strncpy(s, td, len); |
| 31 |
s[len-1] = '\0'; |
| 32 |
return s; |
| 33 |
} |
| 34 |
/* check where TMP and TEMP point to */ |
| 35 |
ts = getenv("TMP"); |
| 36 |
if (ts != NULL && access(ts, W_OK) == 0) { |
| 37 |
strncpy(td, ts, sizeof(td)); |
| 38 |
td[sizeof(td)-1] = '\0'; |
| 39 |
} |
| 40 |
if (ts == NULL) { |
| 41 |
ts = getenv("TEMP"); |
| 42 |
if (ts != NULL && access(ts, W_OK) == 0) { |
| 43 |
strncpy(td, ts, sizeof(td)); |
| 44 |
td[sizeof(td)-1] = '\0'; |
| 45 |
} |
| 46 |
} |
| 47 |
/* check the platform specific default paths in order */ |
| 48 |
while (ts == NULL) { |
| 49 |
if (defaultpaths[i] == NULL) { |
| 50 |
break; |
| 51 |
} |
| 52 |
if (access(defaultpaths[i], W_OK) == 0) { |
| 53 |
ts = strncpy(td, defaultpaths[i], sizeof(td)); |
| 54 |
td[sizeof(td)-1] = '\0'; |
| 55 |
break; |
| 56 |
} |
| 57 |
i++; |
| 58 |
} |
| 59 |
/* we found something */ |
| 60 |
if (ts != NULL) { |
| 61 |
if (s == NULL) { return td; } |
| 62 |
strncpy(s, ts, len); |
| 63 |
s[len-1] = '\0'; |
| 64 |
return s; |
| 65 |
} |
| 66 |
return NULL; |
| 67 |
} |
| 68 |
|
| 69 |
|
| 70 |
/* Concatenate two strings, leaving exactly one DIRSEP in between */ |
| 71 |
char * |
| 72 |
append_filepath(char *s1, char *s2, size_t len) |
| 73 |
{ |
| 74 |
size_t siz; |
| 75 |
char *s; |
| 76 |
|
| 77 |
siz = strlen(s1); |
| 78 |
if (siz > 0) { |
| 79 |
/* XXX siz > len is an error */ |
| 80 |
while (siz > 1 && ISDIRSEP(s1[siz-1])) { |
| 81 |
s1[siz-1] = '\0'; |
| 82 |
siz--; |
| 83 |
} |
| 84 |
if (siz+1 <= len) { |
| 85 |
s1[siz] = DIRSEP; |
| 86 |
siz++; |
| 87 |
} |
| 88 |
} else if (len >= 2) { /* first path empty */ |
| 89 |
s1[0] = CURDIR; |
| 90 |
s1[1] = DIRSEP; |
| 91 |
siz = 2; |
| 92 |
} else { |
| 93 |
return NULL; |
| 94 |
} |
| 95 |
while (ISDIRSEP(s2[0])) { |
| 96 |
s2++; |
| 97 |
} |
| 98 |
s = strncat(s1, s2, len-siz); |
| 99 |
return s; |
| 100 |
} |
| 101 |
|
| 102 |
|
| 103 |
/* Do the actual work for tempfiles, except for the uniquification */ |
| 104 |
static char * |
| 105 |
prepare_tmpname(char *s, size_t len, char *templ) |
| 106 |
{ |
| 107 |
static char lp[PATH_MAX] = "\0"; |
| 108 |
char *ts = NULL; |
| 109 |
|
| 110 |
if (s == NULL) { /* return our static string */ |
| 111 |
s = lp; |
| 112 |
len = sizeof(lp); |
| 113 |
} |
| 114 |
|
| 115 |
ts = temp_directory(s, len); |
| 116 |
if (ts == NULL) { return NULL; } |
| 117 |
ts = append_filepath(ts, templ != NULL ? templ : TEMPFILE_TEMPLATE, len); |
| 118 |
return ts; |
| 119 |
} |
| 120 |
|
| 121 |
|
| 122 |
/* Compose a *currently* unique name within a temporary directory */ |
| 123 |
/* If s is NULL, we return a static string */ |
| 124 |
/* If templ is NULL, we take our default template */ |
| 125 |
/* WARNING: On Windows, there's a maximum of 27 unique names within |
| 126 |
one process for the same template. */ |
| 127 |
char * |
| 128 |
temp_filename(char *s, size_t len, char *templ) |
| 129 |
{ |
| 130 |
char *ts = NULL; |
| 131 |
|
| 132 |
ts = prepare_tmpname(s, len, templ); |
| 133 |
if (ts == NULL) { return NULL; } |
| 134 |
return mktemp(ts); |
| 135 |
} |
| 136 |
|
| 137 |
|
| 138 |
/* Open a unique temp file in a safe way (not safe on Windows) */ |
| 139 |
/* If s is NULL, we use a static string the caller won't learn about */ |
| 140 |
/* If templ is NULL, we take our default template */ |
| 141 |
/* This one is supposed to protect against race conditions on unix */ |
| 142 |
/* WARNING: On Windows, there's no protection against race conditions */ |
| 143 |
/* WARNING: On Windows, there's a maximum of 27 unique names within |
| 144 |
one process for the same template. */ |
| 145 |
int |
| 146 |
temp_fd(char *s, size_t len, char *templ) |
| 147 |
{ |
| 148 |
char *ts = NULL; |
| 149 |
|
| 150 |
ts = prepare_tmpname(s, len, templ); |
| 151 |
if (ts == NULL) return -1; |
| 152 |
#if defined(_WIN32) || defined(_WIN64) |
| 153 |
ts = mktemp(ts); |
| 154 |
if (ts == NULL) return -1; |
| 155 |
return open(ts, O_CREAT|O_EXCL, S_IRUSR|S_IWUSR); |
| 156 |
#else |
| 157 |
return mkstemp(ts); |
| 158 |
#endif |
| 159 |
} |
| 160 |
|
| 161 |
/* As above, but returns a file pointer instead of a descriptor */ |
| 162 |
FILE * |
| 163 |
temp_fp(char *s, size_t len, char *templ) |
| 164 |
{ |
| 165 |
int fd = temp_fd(s, len, templ); |
| 166 |
if (fd < 0) return NULL; |
| 167 |
return fdopen(fd, "w+"); |
| 168 |
} |
| 169 |
|
| 170 |
|
| 171 |
#ifdef TEST_MODULE |
| 172 |
int main() |
| 173 |
{ |
| 174 |
static char p[PATH_MAX] = "\0"; |
| 175 |
char * pp, *qq = NULL; |
| 176 |
pp = temp_directory(p, sizeof(p)); |
| 177 |
printf("%s\n", pp); |
| 178 |
|
| 179 |
qq = temp_filename(pp, sizeof(p), "//something/else_XXXXXX"); |
| 180 |
printf("%s\n", qq); |
| 181 |
|
| 182 |
qq = temp_filename(pp, sizeof(p), NULL); |
| 183 |
printf("%s\n", qq); |
| 184 |
} |
| 185 |
#endif |
| 186 |
|
