compiler/posixc/fcntl.c

   1 /*
   2     Copyright © 1995-2012, The AROS Development Team. All rights reserved.
   3     $Id$
   4 */
   5
   6 #include <proto/dos.h>
   7
   8 #include <errno.h>
   9 #include <stdarg.h>
  10 #include <unistd.h>
  11
  12 #include "__fdesc.h"
  13
  14 /*****************************************************************************
  15
  16     NAME */
  17 #include <fcntl.h>
  18
  19         int fcntl(
  20
  21 /*  SYNOPSIS */
  22         int fd,
  23         int cmd,
  24         ...)
  25
  26 /*  FUNCTION
  27         Perform operation specified in cmd on the file descriptor fd.
  28         Some operations require additional arguments, in this case they
  29         follow the cmd argument. The following operations are available:
  30
  31         F_DUPFD (int)  - Duplicate file descriptor fd as the lowest numbered
  32                          file descriptor greater or equal to the operation
  33                          argument.
  34
  35         F_GETFD (void) - Read the file descriptor flags
  36
  37         F_SETFD (int)  - Set the file descriptor flags to value given in
  38                          the operation argument
  39
  40         F_GETFL (void) - Read the file status flags
  41
  42         F_SETFL (int)  - Set the file status flags to value given in the
  43                          operation argument.
  44
  45         File descriptor flags are zero or more ORed constants:
  46
  47         FD_CLOEXEC - File descriptor will be closed during execve()
  48
  49         File descriptor flags are not copied during duplication of file
  50         descriptors.
  51
  52         File status flags are the flags given as mode parameter to open()
  53         function call. You can change only a few file status flags in opened
  54         file descriptor: O_NONBLOCK, O_APPEND and O_ASYNC. Any other file
  55         status flags passed in F_SETFL argument will be ignored.
  56
  57         All duplicated file descriptors share the same set of file status
  58         flags.
  59
  60     INPUTS
  61         fd - File descriptor to perform operation on.
  62         cmd - Operation specifier.
  63         ... - Operation arguments.
  64
  65     RESULT
  66         The return value of the function depends on the performed operation:
  67
  68         F_DUPFD  - New duplicated file descriptor
  69
  70         F_GETFD  - File descriptor flags
  71
  72         F_SETFD  - 0
  73
  74         F_GETFL  - File status flags
  75
  76         F_SETFL  - 0 on success, -1 on error. In case of error a global errno
  77                    variable is set.
  78
  79     NOTES
  80
  81     EXAMPLE
  82
  83     BUGS
  84
  85     SEE ALSO
  86         open()
  87
  88     INTERNALS
  89
  90 ******************************************************************************/
  91 {
  92     fdesc *desc = __getfdesc(fd);
  93
  94     if (!desc)
  95     {
  96         errno = EBADF;
  97         return -1;
  98     }
  99
 100     switch (cmd)
 101     {
 102         case F_DUPFD:
 103         {
 104             va_list ap;
 105             int     arg;
 106
 107             va_start(ap, cmd);
 108             arg = va_arg(ap, int);
 109             va_end(ap);
 110
 111             /*
 112                 FIXME: FD_CLOEXEC must be off on the copy, once this flag
 113                        is supported (related to F_GETFD and F_SETFD).
 114             */
 115
 116             return dup2(fd, __getfirstfd(arg));
 117         }
 118         case F_GETFD:
 119             return desc->fdflags;
 120
 121         case F_SETFD:
 122         {
 123             va_list ap;
 124             int     arg;
 125
 126             va_start(ap, cmd);
 127             arg = va_arg(ap, int);
 128             va_end(ap);
 129
 130             desc->fdflags = arg;
 131             return 0;
 132         }
 133
 134         case F_GETFL:
 135             return desc->fcb->flags & (O_NONBLOCK|O_APPEND|O_ASYNC);
 136
 137         case F_SETFL:
 138         {
 139             va_list ap;
 140             int     arg;
 141             int     oldmode = __oflags2amode(desc->fcb->flags & ~(O_NONBLOCK|O_APPEND|O_ASYNC));
 142
 143             va_start(ap, cmd);
 144             arg = va_arg(ap, int);
 145             va_end(ap);
 146
 147             arg &= (O_NONBLOCK|O_APPEND|O_ASYNC);
 148
 149             if (ChangeMode(CHANGE_FH, desc->fcb->handle, oldmode | __oflags2amode(arg)) == DOSTRUE)
 150             {
 151                 desc->fcb->flags &= ~(O_NONBLOCK|O_APPEND|O_ASYNC);
 152                 desc->fcb->flags |= arg;
 153                 return 0;
 154             }
 155
 156             errno = __stdc_ioerr2errno(IoErr());
 157             return -1;
 158         }
 159
 160         default:
 161             errno = EINVAL;
 162             return -1;
 163     }
 164 }