sys/src/ape/lib/ap/plan9/access.c

   1 #include "lib.h"
   2 #include <string.h>
   3 #include <sys/stat.h>
   4 #include <fcntl.h>
   5 #include <unistd.h>
   6 #include <errno.h>
   7 #include <stdlib.h>
   8 #include "sys9.h"
   9 #include "dir.h"
  10
  11 int
  12 access(const char *name, int mode)
  13 {
  14         int fd, n;
  15         Dir *db;
  16         struct stat st;
  17         static char omode[] = {
  18                 0,
  19                 3,
  20                 1,
  21                 2,
  22                 0,
  23                 2,
  24                 2,
  25                 2
  26         };
  27         char tname[1024];
  28
  29         if(mode == 0){
  30                 db = _dirstat(name);
  31                 if(db == nil){
  32                         _syserrno();
  33                         return -1;
  34                 }
  35                 free(db);
  36                 return 0;
  37         }
  38         fd = open(name, omode[mode&7]);
  39         if(fd >= 0){
  40                 close(fd);
  41                 return 0;
  42         }
  43         else if(stat(name, &st)==0 && S_ISDIR(st.st_mode)){
  44                 if(mode & (R_OK|X_OK)){
  45                         fd = open(name, O_RDONLY);
  46                         if(fd < 0)
  47                                 return -1;
  48                         close(fd);
  49                 }
  50                 if(mode & W_OK){
  51                         strncpy(tname, name, sizeof(tname)-9);
  52                         strcat(tname, "/_AcChAcK");
  53                         fd = creat(tname, 0666);
  54                         if(fd < 0)
  55                                 return -1;
  56                         close(fd);
  57                         _REMOVE(tname);
  58                 }
  59                 return 0;
  60         }
  61         return -1;
  62 }