summaryrefslogtreecommitdiffstats
path: root/libc-bottom-half/cloudlibc/src/libc/unistd/pwrite.c
blob: f80bc406b9a0ec311107a76c300a54b279b988c7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
// Copyright (c) 2015-2016 Nuxi, https://nuxi.nl/
//
// SPDX-License-Identifier: BSD-2-Clause

#include <wasi/api.h>
#include <errno.h>
#include <unistd.h>

ssize_t pwrite(int fildes, const void *buf, size_t nbyte, off_t offset) {
  if (offset < 0) {
    errno = EINVAL;
    return -1;
  }
  __wasi_ciovec_t iov = {.buf = buf, .buf_len = nbyte};
  size_t bytes_written;
  __wasi_errno_t error =
      __wasi_fd_pwrite(fildes, &iov, 1, offset, &bytes_written);
  if (error != 0) {
    __wasi_fdstat_t fds;
    if (error == ENOTCAPABLE && __wasi_fd_fdstat_get(fildes, &fds) == 0) {
      // Determine why we got ENOTCAPABLE.
      if ((fds.fs_rights_base & __WASI_RIGHTS_FD_WRITE) == 0)
        error = EBADF;
      else
        error = ESPIPE;
    }
    errno = error;
    return -1;
  }
  return bytes_written;
}