tools/perf/util/path.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * I'm tired of doing "vsnprintf()" etc just to open a
   4  * file, so here's a "return static buffer with printf"
   5  * interface for paths.
   6  *
   7  * It's obviously not thread-safe. Sue me. But it's quite
   8  * useful for doing things like
   9  *
  10  *   f = open(mkpath("%s/%s.perf", base, name), O_RDONLY);
  11  *
  12  * which is what it's designed for.
  13  */
  14 #include "path.h"
  15 #include "cache.h"
  16 #include <linux/kernel.h>
  17 #include <limits.h>
  18 #include <stdio.h>
  19 #include <string.h>
  20 #include <sys/types.h>
  21 #include <sys/stat.h>
  22 #include <dirent.h>
  23 #include <unistd.h>
  24
  25 static char bad_path[] = "/bad-path/";
  26 /*
  27  * One hack:
  28  */
  29 static char *get_pathname(void)
  30 {
  31         static char pathname_array[4][PATH_MAX];
  32         static int idx;
  33
  34         return pathname_array[3 & ++idx];
  35 }
  36
  37 static char *cleanup_path(char *path)
  38 {
  39         /* Clean it up */
  40         if (!memcmp(path, "./", 2)) {
  41                 path += 2;
  42                 while (*path == '/')
  43                         path++;
  44         }
  45         return path;
  46 }
  47
  48 char *mkpath(const char *fmt, ...)
  49 {
  50         va_list args;
  51         unsigned len;
  52         char *pathname = get_pathname();
  53
  54         va_start(args, fmt);
  55         len = vsnprintf(pathname, PATH_MAX, fmt, args);
  56         va_end(args);
  57         if (len >= PATH_MAX)
  58                 return bad_path;
  59         return cleanup_path(pathname);
  60 }
  61
  62 int path__join(char *bf, size_t size, const char *path1, const char *path2)
  63 {
  64         return scnprintf(bf, size, "%s%s%s", path1, path1[0] ? "/" : "", path2);
  65 }
  66
  67 int path__join3(char *bf, size_t size, const char *path1, const char *path2, const char *path3)
  68 {
  69         return scnprintf(bf, size, "%s%s%s%s%s", path1, path1[0] ? "/" : "",
  70                          path2, path2[0] ? "/" : "", path3);
  71 }
  72
  73 bool is_regular_file(const char *file)
  74 {
  75         struct stat st;
  76
  77         if (stat(file, &st))
  78                 return false;
  79
  80         return S_ISREG(st.st_mode);
  81 }
  82
  83 /* Helper function for filesystems that return a dent->d_type DT_UNKNOWN */
  84 bool is_directory(const char *base_path, const struct dirent *dent)
  85 {
  86         char path[PATH_MAX];
  87         struct stat st;
  88
  89         sprintf(path, "%s/%s", base_path, dent->d_name);
  90         if (stat(path, &st))
  91                 return false;
  92
  93         return S_ISDIR(st.st_mode);
  94 }