compat/snprintf.c

   1 #include "../git-compat-util.h"
   2
   3 /*
   4  * The size parameter specifies the available space, i.e. includes
   5  * the trailing NUL byte; but Windows's vsnprintf expects the
   6  * number of characters to write without the trailing NUL.
   7  */
   8 #ifndef SNPRINTF_SIZE_CORR
   9 #define SNPRINTF_SIZE_CORR 0
  10 #endif
  11
  12 #undef vsnprintf
  13 int git_vsnprintf(char *str, size_t maxsize, const char *format, va_list ap)
  14 {
  15         char *s;
  16         int ret;
  17
  18         ret = vsnprintf(str, maxsize-SNPRINTF_SIZE_CORR, format, ap);
  19         if (ret != -1) {
  20                 /* Windows does not NUL-terminate if result fits exactly */
  21                 str[ret] = 0;
  22                 return ret;
  23         }
  24
  25         s = NULL;
  26         if (maxsize < 128)
  27                 maxsize = 128;
  28
  29         while (ret == -1) {
  30                 maxsize *= 4;
  31                 str = realloc(s, maxsize);
  32                 if (! str)
  33                         break;
  34                 s = str;
  35                 ret = vsnprintf(str, maxsize-SNPRINTF_SIZE_CORR, format, ap);
  36         }
  37         free(s);
  38         return ret;
  39 }
  40
  41 int git_snprintf(char *str, size_t maxsize, const char *format, ...)
  42 {
  43         va_list ap;
  44         int ret;
  45
  46         va_start(ap, format);
  47         ret = git_vsnprintf(str, maxsize, format, ap);
  48         va_end(ap);
  49
  50         return ret;
  51 }
  52