insilmaril@80: #include "mkdtemp.h"
insilmaril@80: #include <stdint.h>
insilmaril@80: #include <string.h>
insilmaril@80: #include <errno.h>
insilmaril@80: #include <io.h>
insilmaril@80: 
insilmaril@80: char *
insilmaril@80: mkdtemp(char *tmpl)
insilmaril@80: {
insilmaril@80:     // Implementation based on GLIBC implementation.
insilmaril@80: 
insilmaril@80:     static const char letters[] =
insilmaril@80:         "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
insilmaril@80: 
insilmaril@80:     static uint64_t value;
insilmaril@80: 
insilmaril@80:     const unsigned int ATTEMPTS_MIN = (62 * 62 * 62);
insilmaril@80: 
insilmaril@80:     int save_errno = errno;
insilmaril@80: 
insilmaril@80:     size_t len = strlen(tmpl);
insilmaril@80:     if (len < 6 || strcmp(&tmpl[len - 6], "XXXXXX"))
insilmaril@80:     {
insilmaril@80:         errno = EINVAL;
insilmaril@80:         return NULL;
insilmaril@80:     }
insilmaril@80: 
insilmaril@80:     char *XXXXXX = &tmpl[len - 6];
insilmaril@80: 
insilmaril@80:     uint64_t random_time_bits = time(NULL);
insilmaril@80: 
insilmaril@80:     value += (random_time_bits ^ getpid());
insilmaril@80: 
insilmaril@80:     unsigned int count;
insilmaril@80:     for (count = 0; count < ATTEMPTS_MIN; value += 7777, ++count)
insilmaril@80:     {
insilmaril@80:         uint64_t v = value;
insilmaril@80: 
insilmaril@80:         XXXXXX[0] = letters[v % 62];
insilmaril@80:         v /= 62;
insilmaril@80:         XXXXXX[1] = letters[v % 62];
insilmaril@80:         v /= 62;
insilmaril@80:         XXXXXX[2] = letters[v % 62];
insilmaril@80:         v /= 62;
insilmaril@80:         XXXXXX[3] = letters[v % 62];
insilmaril@80:         v /= 62;
insilmaril@80:         XXXXXX[4] = letters[v % 62];
insilmaril@80:         v /= 62;
insilmaril@80:         XXXXXX[5] = letters[v % 62];
insilmaril@80: 
insilmaril@80: 		if (mkdir(tmpl) == 0)
insilmaril@80:         {
insilmaril@80:             errno = save_errno;
insilmaril@80: 			return tmpl;
insilmaril@80:         }
insilmaril@80: 
insilmaril@80: 		if (errno != EEXIST)
insilmaril@80: 			return NULL;
insilmaril@80:     }
insilmaril@80: 
insilmaril@80:     errno = EEXIST;
insilmaril@80:     return NULL;
insilmaril@80: }