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#ifndef lint |
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static const char RCSid[] = "$Id: paths.c,v 2.3 2003/06/30 14:59:11 schorsch Exp $"; |
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#endif |
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/* |
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* Find a writeable tempfile directory. |
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* Create unique filenames therein, and possibly open the file. |
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* |
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*/ |
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|
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#include "copyright.h" |
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|
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#include "paths.h" |
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|
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|
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#define TEMPFILE_TEMPLATE "rtXXXXXX" |
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static const char *defaultpaths[] = DEFAULT_TEMPDIRS; |
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|
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|
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/* Return a writeable directory for temporary files */ |
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/* If s is NULL, we return a static string */ |
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char * |
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temp_directory(char *s, size_t len) |
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{ |
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static char td[PATH_MAX]; /* remember */ |
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char * ts = NULL; |
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int i = 0; |
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|
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if (td[0] != '\0') { /* we already have one */ |
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if (s == NULL) { return td; } |
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strncpy(s, td, len); |
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s[len-1] = '\0'; |
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return s; |
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} |
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/* check where TMP and TEMP point to */ |
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ts = getenv("TMP"); |
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if (ts != NULL && access(ts, W_OK) == 0) { |
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strncpy(td, ts, sizeof(td)); |
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td[sizeof(td)-1] = '\0'; |
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} |
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if (ts == NULL) { |
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ts = getenv("TEMP"); |
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if (ts != NULL && access(ts, W_OK) == 0) { |
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strncpy(td, ts, sizeof(td)); |
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td[sizeof(td)-1] = '\0'; |
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} |
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} |
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/* check the platform specific default paths in order */ |
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while (ts == NULL) { |
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if (defaultpaths[i] == NULL) { |
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break; |
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} |
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if (access(defaultpaths[i], W_OK) == 0) { |
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ts = strncpy(td, defaultpaths[i], sizeof(td)); |
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td[sizeof(td)-1] = '\0'; |
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break; |
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} |
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i++; |
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} |
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/* we found something */ |
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if (ts != NULL) { |
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if (s == NULL) { return td; } |
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strncpy(s, ts, len); |
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s[len-1] = '\0'; |
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return s; |
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} |
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return NULL; |
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} |
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|
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|
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/* Concatenate two strings, leaving exactly one DIRSEP in between */ |
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char * |
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append_filepath(char *s1, char *s2, size_t len) |
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{ |
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size_t siz; |
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char *s; |
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|
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siz = strlen(s1); |
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if (siz > 0) { |
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/* XXX siz > len is an error */ |
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while (siz > 1 && ISDIRSEP(s1[siz-1])) { |
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s1[siz-1] = '\0'; |
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siz--; |
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} |
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if (siz+1 <= len) { |
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s1[siz] = DIRSEP; |
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siz++; |
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} |
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} else if (len >= 2) { /* first path empty */ |
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s1[0] = CURDIR; |
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s1[1] = DIRSEP; |
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siz = 2; |
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} else { |
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return NULL; |
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} |
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while (ISDIRSEP(s2[0])) { |
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s2++; |
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} |
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s = strncat(s1, s2, len-siz); |
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return s; |
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} |
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|
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|
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/* Do the actual work for tempfiles, except for the uniquification */ |
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static char * |
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prepare_tmpname(char *s, size_t len, char *templ) |
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{ |
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static char lp[PATH_MAX] = "\0"; |
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char *ts = NULL; |
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|
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if (s == NULL) { /* return our static string */ |
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s = lp; |
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len = sizeof(lp); |
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} |
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|
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ts = temp_directory(s, len); |
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if (ts == NULL) { return NULL; } |
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ts = append_filepath(ts, templ != NULL ? templ : TEMPFILE_TEMPLATE, len); |
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return ts; |
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} |
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|
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|
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/* Compose a *currently* unique name within a temporary directory */ |
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/* If s is NULL, we return a static string */ |
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/* If templ is NULL, we take our default template */ |
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/* WARNING: On Windows, there's a maximum of 27 unique names within |
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one process for the same template. */ |
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char * |
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temp_filename(char *s, size_t len, char *templ) |
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{ |
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char *ts = NULL; |
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|
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ts = prepare_tmpname(s, len, templ); |
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if (ts == NULL) { return NULL; } |
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return mktemp(ts); |
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} |
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|
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|
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/* Open a unique temp file in a safe way (not safe on Windows) */ |
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/* If s is NULL, we use a static string the caller won't learn about */ |
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/* If templ is NULL, we take our default template */ |
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/* This one is supposed to protect against race conditions on unix */ |
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/* WARNING: On Windows, there's no protection against race conditions */ |
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/* WARNING: On Windows, there's a maximum of 27 unique names within |
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one process for the same template. */ |
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int |
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temp_fd(char *s, size_t len, char *templ) |
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{ |
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char *ts = NULL; |
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|
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ts = prepare_tmpname(s, len, templ); |
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if (ts == NULL) return -1; |
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#ifdef _WIN32 |
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ts = mktemp(ts); |
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if (ts == NULL) return -1; |
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return open(ts, O_CREAT|O_EXCL, S_IRUSR|S_IWUSR); |
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#else |
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return mkstemp(ts); |
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#endif |
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} |
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|
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/* As above, but returns a file pointer instead of a descriptor */ |
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FILE * |
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temp_fp(char *s, size_t len, char *templ) |
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{ |
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int fd = temp_fd(s, len, templ); |
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if (fd < 0) return NULL; |
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return fdopen(fd, "w+"); |
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} |
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|
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|
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#ifdef TEST_MODULE |
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int main() |
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{ |
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static char p[PATH_MAX] = "\0"; |
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char * pp, *qq = NULL; |
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pp = temp_directory(p, sizeof(p)); |
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printf("%s\n", pp); |
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|
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qq = temp_filename(pp, sizeof(p), "//something/else_XXXXXX"); |
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printf("%s\n", qq); |
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|
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qq = temp_filename(pp, sizeof(p), NULL); |
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printf("%s\n", qq); |
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} |
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#endif |
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|
