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 "path.h"
  15 #include <linux/kernel.h>
  16 #include <limits.h>
  17 #include <stdio.h>
  18 #include <sys/types.h>
  19 #include <sys/stat.h>
  20 #include <unistd.h>
  21
  22 static char bad_path[] = "/bad-path/";
  23 /*
  24  * One hack:
  25  */
  26 static char *get_pathname(void)
  27 {
  28         static char pathname_array[4][PATH_MAX];
  29         static int idx;
  30
  31         return pathname_array[3 & ++idx];
  32 }
  33
  34 static char *cleanup_path(char *path)
  35 {
  36         /* Clean it up */
  37         if (!memcmp(path, "./", 2)) {
  38                 path += 2;
  39                 while (*path == '/')
  40                         path++;
  41         }
  42         return path;
  43 }
  44
  45 char *mkpath(const char *fmt, ...)
  46 {
  47         va_list args;
  48         unsigned len;
  49         char *pathname = get_pathname();
  50
  51         va_start(args, fmt);
  52         len = vsnprintf(pathname, PATH_MAX, fmt, args);
  53         va_end(args);
  54         if (len >= PATH_MAX)
  55                 return bad_path;
  56         return cleanup_path(pathname);
  57 }
  58
  59 int path__join(char *bf, size_t size, const char *path1, const char *path2)
  60 {
  61         return scnprintf(bf, size, "%s%s%s", path1, path1[0] ? "/" : "", path2);
  62 }
  63
  64 int path__join3(char *bf, size_t size, const char *path1, const char *path2, const char *path3)
  65 {
  66         return scnprintf(bf, size, "%s%s%s%s%s", path1, path1[0] ? "/" : "",
  67                          path2, path2[0] ? "/" : "", path3);
  68 }
  69
  70 bool is_regular_file(const char *file)
  71 {
  72         struct stat st;
  73
  74         if (stat(file, &st))
  75                 return false;
  76
  77         return S_ISREG(st.st_mode);
  78 }