/**
* fopen
*
* @return FILE pointer - upon successful completion,
* NULL - otherwise
*/
FILE *
fopen (const char *path, /**< file path */
const char *mode) /**< file open mode */
{
bool may_read = false;
bool may_write = false;
bool truncate = false;
bool create_if_not_exist = false;
bool position_at_end = false;
LIBC_ASSERT (path != NULL && mode != NULL);
LIBC_ASSERT (mode[1] == '+' || mode[1] == '\0');
switch (mode[0])
{
case 'r':
{
may_read = true;
may_write = (mode[1] == '+');
break;
}
case 'w':
{
may_write = true;
truncate = true;
create_if_not_exist = true;
may_read = (mode[1] == '+');
break;
}
case 'a':
{
may_write = true;
position_at_end = true;
create_if_not_exist = true;
if (mode[1] == '+')
{
/* Not supported */
LIBC_UNREACHABLE ();
}
break;
}
default:
{
LIBC_UNREACHABLE ();
}
}
int flags = 0;
int access = S_IRUSR | S_IWUSR;
if (may_read && !may_write)
{
flags = O_RDONLY;
}
else if (!may_read && may_write)
{
flags = O_WRONLY;
}
else
{
LIBC_ASSERT (may_read && may_write);
flags = O_RDWR;
}
if (truncate)
{
flags |= O_TRUNC;
}
if (create_if_not_exist)
{
flags |= O_CREAT;
}
if (position_at_end)
{
flags |= O_APPEND;
}
long int ret = syscall_3 (__NR_open, (long int) path, flags, access);
return (void *) (uintptr_t) (ret);
} /* fopen */
/**
* The rewind () function sets the file position indicator
* for the stream pointed to by STREAM to the beginning of the file.
*/
void
rewind (FILE *stream) /**< stream pointer */
{
syscall_3 (__NR_lseek, (long int) stream, 0, SEEK_SET);
} /* rewind */
/**
* fopen
*
* @return FILE pointer - upon successful completion,
* NULL - otherwise
*/
FILE *
fopen (const char *path, /**< file path */
const char *mode) /**< file open mode */
{
bool may_read = false;
bool may_write = false;
bool truncate = false;
bool create_if_not_exist = false;
bool position_at_end = false;
assert (path != NULL && mode != NULL);
assert (mode[1] == '+' || mode[1] == '\0');
switch (mode[0])
{
case 'r':
{
may_read = true;
may_write = (mode[1] == '+');
break;
}
case 'w':
{
may_write = true;
truncate = true;
create_if_not_exist = true;
may_read = (mode[1] == '+');
break;
}
case 'a':
{
may_write = true;
position_at_end = true;
create_if_not_exist = true;
if (mode[1] == '+')
{
assert (false && "unsupported mode a+");
}
break;
}
default:
{
assert (false && "unsupported mode");
}
}
int flags = 0;
int access = S_IRUSR | S_IWUSR;
if (may_read && !may_write)
{
flags = O_RDONLY;
}
else if (!may_read && may_write)
{
flags = O_WRONLY;
}
else
{
assert (may_read && may_write);
flags = O_RDWR;
}
if (truncate)
{
flags |= O_TRUNC;
}
if (create_if_not_exist)
{
flags |= O_CREAT;
}
if (position_at_end)
{
flags |= O_APPEND;
}
long int ret = syscall_3 (SYSCALL_NO (open), (long int) path, flags, access);
return ((ret < 0) ? NULL : (void *) (uintptr_t) (ret));
} /* fopen */
