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 "cache.h"
  15 #include "path.h"
  16 #include <linux/kernel.h>
  17 #include <limits.h>
  18 #include <stdio.h>
  19 #include <sys/types.h>
  20 #include <sys/stat.h>
  21 #include <dirent.h>
  22 #include <unistd.h>
  23
  24 static char bad_path[] = "/bad-path/";
  25 /*
  26  * One hack:
  27  */
  28 static char *get_pathname(void)
  29 {
  30         static char pathname_array[4][PATH_MAX];
  31         static int idx;
  32
  33         return pathname_array[3 & ++idx];
  34 }
  35
  36 static char *cleanup_path(char *path)
  37 {
  38         /* Clean it up */
  39         if (!memcmp(path, "./", 2)) {
  40                 path += 2;
  41                 while (*path == '/')
  42                         path++;
  43         }
  44         return path;
  45 }
  46
  47 char *mkpath(const char *fmt, ...)
  48 {
  49         va_list args;
  50         unsigned len;
  51         char *pathname = get_pathname();
  52
  53         va_start(args, fmt);
  54         len = vsnprintf(pathname, PATH_MAX, fmt, args);
  55         va_end(args);
  56         if (len >= PATH_MAX)
  57                 return bad_path;
  58         return cleanup_path(pathname);
  59 }
  60
  61 int path__join(char *bf, size_t size, const char *path1, const char *path2)
  62 {
  63         return scnprintf(bf, size, "%s%s%s", path1, path1[0] ? "/" : "", path2);
  64 }
  65
  66 int path__join3(char *bf, size_t size, const char *path1, const char *path2, const char *path3)
  67 {
  68         return scnprintf(bf, size, "%s%s%s%s%s", path1, path1[0] ? "/" : "",
  69                          path2, path2[0] ? "/" : "", path3);
  70 }
  71
  72 bool is_regular_file(const char *file)
  73 {
  74         struct stat st;
  75
  76         if (stat(file, &st))
  77                 return false;
  78
  79         return S_ISREG(st.st_mode);
  80 }
  81
  82 /* Helper function for filesystems that return a dent->d_type DT_UNKNOWN */
  83 bool is_directory(const char *base_path, const struct dirent *dent)
  84 {
  85         char path[PATH_MAX];
  86         struct stat st;
  87
  88         sprintf(path, "%s/%s", base_path, dent->d_name);
  89         if (stat(path, &st))
  90                 return false;
  91
  92         return S_ISDIR(st.st_mode);
  93 }