lib/libc/posix/_fpathconf.c

   1 /* POSIX fpathconf (Sec. 5.7.1)                 Author: Andy Tanenbaum */
   2
   3 #include <lib.h>
   4 #define fstat           _fstat
   5 #define fpathconf       _fpathconf
   6 #include <sys/stat.h>
   7 #include <errno.h>
   8 #include <limits.h>
   9 #include <unistd.h>
  10 #include <termios.h>
  11
  12 PUBLIC long fpathconf(fd, name)
  13 int fd;                         /* file descriptor being interrogated */
  14 int name;                       /* property being inspected */
  15 {
  16 /* POSIX allows some of the values in <limits.h> to be increased at
  17  * run time.  The pathconf and fpathconf functions allow these values
  18  * to be checked at run time.  MINIX does not use this facility.
  19  * The run-time limits are those given in <limits.h>.
  20  */
  21
  22   struct stat stbuf;
  23
  24   switch(name) {
  25         case _PC_LINK_MAX:
  26                 /* Fstat the file.  If that fails, return -1. */
  27                 if (fstat(fd, &stbuf) != 0) return(-1);
  28                 if (S_ISDIR(stbuf.st_mode))
  29                         return(1L);     /* no links to directories */
  30                 else
  31                         return( (long) LINK_MAX);
  32
  33         case _PC_MAX_CANON:
  34                 return( (long) MAX_CANON);
  35
  36         case _PC_MAX_INPUT:
  37                 return( (long) MAX_INPUT);
  38
  39         case _PC_NAME_MAX:
  40                 return( (long) NAME_MAX);
  41
  42         case _PC_PATH_MAX:
  43                 return( (long) PATH_MAX);
  44
  45         case _PC_PIPE_BUF:
  46                 return( (long) PIPE_BUF);
  47
  48         case _PC_CHOWN_RESTRICTED:
  49                 return( (long) _POSIX_CHOWN_RESTRICTED);
  50
  51         case _PC_NO_TRUNC:
  52                 return( (long) _POSIX_NO_TRUNC);
  53
  54         case _PC_VDISABLE:
  55                 return( (long) _POSIX_VDISABLE);
  56
  57         default:
  58                 errno = EINVAL;
  59                 return(-1);
  60   }
  61 }