tools/perf/util/path.c

   1 /*
   2  * I'm tired of doing "vsnprintf()" etc just to open a
   3  * file, so here's a "return static buffer with printf"
   4  * interface for paths.
   5  *
   6  * It's obviously not thread-safe. Sue me. But it's quite
   7  * useful for doing things like
   8  *
   9  *   f = open(mkpath("%s/%s.perf", base, name), O_RDONLY);
  10  *
  11  * which is what it's designed for.
  12  */
  13 #include "cache.h"
  14 #include "util.h"
  15 #include <limits.h>
  16
  17 static char bad_path[] = "/bad-path/";
  18 /*
  19  * One hack:
  20  */
  21 static char *get_pathname(void)
  22 {
  23         static char pathname_array[4][PATH_MAX];
  24         static int idx;
  25
  26         return pathname_array[3 & ++idx];
  27 }
  28
  29 static char *cleanup_path(char *path)
  30 {
  31         /* Clean it up */
  32         if (!memcmp(path, "./", 2)) {
  33                 path += 2;
  34                 while (*path == '/')
  35                         path++;
  36         }
  37         return path;
  38 }
  39
  40 char *mkpath(const char *fmt, ...)
  41 {
  42         va_list args;
  43         unsigned len;
  44         char *pathname = get_pathname();
  45
  46         va_start(args, fmt);
  47         len = vsnprintf(pathname, PATH_MAX, fmt, args);
  48         va_end(args);
  49         if (len >= PATH_MAX)
  50                 return bad_path;
  51         return cleanup_path(pathname);
  52 }