cosmopolitan/libc/calls/chdir-nt.c

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8                               :vi │
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney                              │
│                                                                              │
│ Permission to use, copy, modify, and/or distribute this software for         │
│ any purpose with or without fee is hereby granted, provided that the         │
│ above copyright notice and this permission notice appear in all copies.      │
│                                                                              │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
│ PERFORMANCE OF THIS SOFTWARE.                                                │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/calls/syscall-nt.internal.h"
#include "libc/calls/syscall_support-nt.internal.h"
#include "libc/limits.h"
#include "libc/nt/files.h"
#include "libc/nt/process.h"
#include "libc/sysv/errfuns.h"

textwindows int sys_chdir_nt_impl(char16_t path[hasatleast PATH_MAX],
                                  uint32_t len) {
  uint32_t n;
  char16_t var[4];
  if (len && path[len - 1] != u'\\') {
    if (len + 2 > PATH_MAX)
      return enametoolong();
    path[len + 0] = u'\\';
    path[len + 1] = u'\0';
  }
  if (SetCurrentDirectory(path)) {
    /*
     * Now we need to set a magic environment variable.
     */
    if ((n = GetCurrentDirectory(PATH_MAX, path))) {
      if (n < PATH_MAX) {
        if (!((path[0] == '/' && path[1] == '/') ||
              (path[0] == '\\' && path[1] == '\\'))) {
          var[0] = '=';
          var[1] = path[0];
          var[2] = ':';
          var[3] = 0;
          if (!SetEnvironmentVariable(var, path))
            return __winerr();
        }
        return 0;
      } else {
        return enametoolong();
      }
    } else {
      return __winerr();
    }
  } else {
    return __fix_enotdir(__winerr(), path);
  }
}

textwindows int sys_chdir_nt(const char *path) {
  int len;
  char16_t path16[PATH_MAX];
  if ((len = __mkntpath(path, path16)) == -1)
    return -1;
  if (!len)
    return enoent();
  return sys_chdir_nt_impl(path16, len);
}