lib/fileutils.c

   1 /*
   2  * Copyright (C) 2012 Sami Kerola <kerolasa@iki.fi>
   3  */
   4
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7 #include <sys/stat.h>
   8 #include <unistd.h>
   9 #include <sys/time.h>
  10 #include <sys/resource.h>
  11
  12 #include "c.h"
  13 #include "fileutils.h"
  14 #include "pathnames.h"
  15 #include "xalloc.h"
  16
  17 /* Create open temporary file in safe way.  Please notice that the
  18  * file permissions are -rw------- by default. */
  19 int xmkstemp(char **tmpname, char *dir)
  20 {
  21         char *localtmp;
  22         char *tmpenv;
  23         mode_t old_mode;
  24         int fd;
  25
  26         /* Some use cases must be capable of being moved atomically
  27          * with rename(2), which is the reason why dir is here.  */
  28         if (dir != NULL)
  29                 tmpenv = dir;
  30         else
  31                 tmpenv = getenv("TMPDIR");
  32
  33         if (tmpenv)
  34                 xasprintf(&localtmp, "%s/%s.XXXXXX", tmpenv,
  35                           program_invocation_short_name);
  36         else
  37                 xasprintf(&localtmp, "%s/%s.XXXXXX", _PATH_TMP,
  38                           program_invocation_short_name);
  39         old_mode = umask(077);
  40         fd = mkostemp(localtmp, O_RDWR|O_CREAT|O_EXCL|O_CLOEXEC);
  41         umask(old_mode);
  42         if (fd == -1) {
  43                 free(localtmp);
  44                 localtmp = NULL;
  45         }
  46         *tmpname = localtmp;
  47         return fd;
  48 }
  49
  50 /*
  51  * portable getdtablesize()
  52  */
  53 int get_fd_tabsize(void)
  54 {
  55         int m;
  56
  57 #if defined(HAVE_GETDTABLESIZE)
  58         m = getdtablesize();
  59 #elif defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE)
  60         struct rlimit rl;
  61
  62         getrlimit(RLIMIT_NOFILE, &rl);
  63         m = rl.rlim_cur;
  64 #elif defined(HAVE_SYSCONF) && defined(_SC_OPEN_MAX)
  65         m = sysconf(_SC_OPEN_MAX);
  66 #else
  67         m = OPEN_MAX;
  68 #endif
  69         return m;
  70 }
  71
  72 #ifdef TEST_PROGRAM
  73 int main(void)
  74 {
  75         FILE *f;
  76         char *tmpname;
  77         f = xfmkstemp(&tmpname, NULL);
  78         unlink(tmpname);
  79         free(tmpname);
  80         fclose(f);
  81         return EXIT_FAILURE;
  82 }
  83 #endif
  84
  85
  86 int mkdir_p(const char *path, mode_t mode)
  87 {
  88         char *p, *dir;
  89         int rc = 0;
  90
  91         if (!path || !*path)
  92                 return -EINVAL;
  93
  94         dir = p = strdup(path);
  95         if (!dir)
  96                 return -ENOMEM;
  97
  98         if (*p == '/')
  99                 p++;
 100
 101         while (p && *p) {
 102                 char *e = strchr(p, '/');
 103                 if (e)
 104                         *e = '\0';
 105                 if (*p) {
 106                         rc = mkdir(dir, mode);
 107                         if (rc && errno != EEXIST)
 108                                 break;
 109                         rc = 0;
 110                 }
 111                 if (!e)
 112                         break;
 113                 *e = '/';
 114                 p = e + 1;
 115         }
 116
 117         free(dir);
 118         return rc;
 119 }
 120
 121 /* returns basename and keeps dirname in the @path, if @path is "/" (root)
 122  * then returns empty string */
 123 char *stripoff_last_component(char *path)
 124 {
 125         char *p = path ? strrchr(path, '/') : NULL;
 126
 127         if (!p)
 128                 return NULL;
 129         *p = '\0';
 130         return p + 1;
 131 }