cpython/Modules/clinic/fcntlmodule.c.h

/*[clinic input]
preserve
[clinic start generated code]*/

#if defined(Py_BUILD_CORE) && !defined(Py_BUILD_CORE_MODULE)
#  include "pycore_gc.h"            // PyGC_Head
#  include "pycore_runtime.h"       // _Py_ID()
#endif


PyDoc_STRVAR(fcntl_fcntl__doc__,
"fcntl($module, fd, cmd, arg=0, /)\n"
"--\n"
"\n"
"Perform the operation `cmd` on file descriptor fd.\n"
"\n"
"The values used for `cmd` are operating system dependent, and are available\n"
"as constants in the fcntl module, using the same names as used in\n"
"the relevant C header files.  The argument arg is optional, and\n"
"defaults to 0; it may be an int or a string.  If arg is given as a string,\n"
"the return value of fcntl is a string of that length, containing the\n"
"resulting value put in the arg buffer by the operating system.  The length\n"
"of the arg string is not allowed to exceed 1024 bytes.  If the arg given\n"
"is an integer or if none is specified, the result value is an integer\n"
"corresponding to the return value of the fcntl call in the C code.");

#define FCNTL_FCNTL_METHODDEF    \
    {"fcntl", _PyCFunction_CAST(fcntl_fcntl), METH_FASTCALL, fcntl_fcntl__doc__},

static PyObject *
fcntl_fcntl_impl(PyObject *module, int fd, int code, PyObject *arg);

static PyObject *
fcntl_fcntl(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
{
    PyObject *return_value = NULL;
    int fd;
    int code;
    PyObject *arg = NULL;

    if (!_PyArg_CheckPositional("fcntl", nargs, 2, 3)) {
        goto exit;
    }
    if (!_PyLong_FileDescriptor_Converter(args[0], &fd)) {
        goto exit;
    }
    code = _PyLong_AsInt(args[1]);
    if (code == -1 && PyErr_Occurred()) {
        goto exit;
    }
    if (nargs < 3) {
        goto skip_optional;
    }
    arg = args[2];
skip_optional:
    return_value = fcntl_fcntl_impl(module, fd, code, arg);

exit:
    return return_value;
}

PyDoc_STRVAR(fcntl_ioctl__doc__,
"ioctl($module, fd, request, arg=0, mutate_flag=True, /)\n"
"--\n"
"\n"
"Perform the operation `request` on file descriptor `fd`.\n"
"\n"
"The values used for `request` are operating system dependent, and are available\n"
"as constants in the fcntl or termios library modules, using the same names as\n"
"used in the relevant C header files.\n"
"\n"
"The argument `arg` is optional, and defaults to 0; it may be an int or a\n"
"buffer containing character data (most likely a string or an array).\n"
"\n"
"If the argument is a mutable buffer (such as an array) and if the\n"
"mutate_flag argument (which is only allowed in this case) is true then the\n"
"buffer is (in effect) passed to the operating system and changes made by\n"
"the OS will be reflected in the contents of the buffer after the call has\n"
"returned.  The return value is the integer returned by the ioctl system\n"
"call.\n"
"\n"
"If the argument is a mutable buffer and the mutable_flag argument is false,\n"
"the behavior is as if a string had been passed.\n"
"\n"
"If the argument is an immutable buffer (most likely a string) then a copy\n"
"of the buffer is passed to the operating system and the return value is a\n"
"string of the same length containing whatever the operating system put in\n"
"the buffer.  The length of the arg buffer in this case is not allowed to\n"
"exceed 1024 bytes.\n"
"\n"
"If the arg given is an integer or if none is specified, the result value is\n"
"an integer corresponding to the return value of the ioctl call in the C\n"
"code.");

#define FCNTL_IOCTL_METHODDEF    \
    {"ioctl", _PyCFunction_CAST(fcntl_ioctl), METH_FASTCALL, fcntl_ioctl__doc__},

static PyObject *
fcntl_ioctl_impl(PyObject *module, int fd, unsigned int code,
                 PyObject *ob_arg, int mutate_arg);

static PyObject *
fcntl_ioctl(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
{
    PyObject *return_value = NULL;
    int fd;
    unsigned int code;
    PyObject *ob_arg = NULL;
    int mutate_arg = 1;

    if (!_PyArg_CheckPositional("ioctl", nargs, 2, 4)) {
        goto exit;
    }
    if (!_PyLong_FileDescriptor_Converter(args[0], &fd)) {
        goto exit;
    }
    code = (unsigned int)PyLong_AsUnsignedLongMask(args[1]);
    if (code == (unsigned int)-1 && PyErr_Occurred()) {
        goto exit;
    }
    if (nargs < 3) {
        goto skip_optional;
    }
    ob_arg = args[2];
    if (nargs < 4) {
        goto skip_optional;
    }
    mutate_arg = PyObject_IsTrue(args[3]);
    if (mutate_arg < 0) {
        goto exit;
    }
skip_optional:
    return_value = fcntl_ioctl_impl(module, fd, code, ob_arg, mutate_arg);

exit:
    return return_value;
}

PyDoc_STRVAR(fcntl_flock__doc__,
"flock($module, fd, operation, /)\n"
"--\n"
"\n"
"Perform the lock operation `operation` on file descriptor `fd`.\n"
"\n"
"See the Unix manual page for flock(2) for details (On some systems, this\n"
"function is emulated using fcntl()).");

#define FCNTL_FLOCK_METHODDEF    \
    {"flock", _PyCFunction_CAST(fcntl_flock), METH_FASTCALL, fcntl_flock__doc__},

static PyObject *
fcntl_flock_impl(PyObject *module, int fd, int code);

static PyObject *
fcntl_flock(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
{
    PyObject *return_value = NULL;
    int fd;
    int code;

    if (!_PyArg_CheckPositional("flock", nargs, 2, 2)) {
        goto exit;
    }
    if (!_PyLong_FileDescriptor_Converter(args[0], &fd)) {
        goto exit;
    }
    code = _PyLong_AsInt(args[1]);
    if (code == -1 && PyErr_Occurred()) {
        goto exit;
    }
    return_value = fcntl_flock_impl(module, fd, code);

exit:
    return return_value;
}

PyDoc_STRVAR(fcntl_lockf__doc__,
"lockf($module, fd, cmd, len=0, start=0, whence=0, /)\n"
"--\n"
"\n"
"A wrapper around the fcntl() locking calls.\n"
"\n"
"`fd` is the file descriptor of the file to lock or unlock, and operation is one\n"
"of the following values:\n"
"\n"
"    LOCK_UN - unlock\n"
"    LOCK_SH - acquire a shared lock\n"
"    LOCK_EX - acquire an exclusive lock\n"
"\n"
"When operation is LOCK_SH or LOCK_EX, it can also be bitwise ORed with\n"
"LOCK_NB to avoid blocking on lock acquisition.  If LOCK_NB is used and the\n"
"lock cannot be acquired, an OSError will be raised and the exception will\n"
"have an errno attribute set to EACCES or EAGAIN (depending on the operating\n"
"system -- for portability, check for either value).\n"
"\n"
"`len` is the number of bytes to lock, with the default meaning to lock to\n"
"EOF.  `start` is the byte offset, relative to `whence`, to that the lock\n"
"starts.  `whence` is as with fileobj.seek(), specifically:\n"
"\n"
"    0 - relative to the start of the file (SEEK_SET)\n"
"    1 - relative to the current buffer position (SEEK_CUR)\n"
"    2 - relative to the end of the file (SEEK_END)");

#define FCNTL_LOCKF_METHODDEF    \
    {"lockf", _PyCFunction_CAST(fcntl_lockf), METH_FASTCALL, fcntl_lockf__doc__},

static PyObject *
fcntl_lockf_impl(PyObject *module, int fd, int code, PyObject *lenobj,
                 PyObject *startobj, int whence);

static PyObject *
fcntl_lockf(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
{
    PyObject *return_value = NULL;
    int fd;
    int code;
    PyObject *lenobj = NULL;
    PyObject *startobj = NULL;
    int whence = 0;

    if (!_PyArg_CheckPositional("lockf", nargs, 2, 5)) {
        goto exit;
    }
    if (!_PyLong_FileDescriptor_Converter(args[0], &fd)) {
        goto exit;
    }
    code = _PyLong_AsInt(args[1]);
    if (code == -1 && PyErr_Occurred()) {
        goto exit;
    }
    if (nargs < 3) {
        goto skip_optional;
    }
    lenobj = args[2];
    if (nargs < 4) {
        goto skip_optional;
    }
    startobj = args[3];
    if (nargs < 5) {
        goto skip_optional;
    }
    whence = _PyLong_AsInt(args[4]);
    if (whence == -1 && PyErr_Occurred()) {
        goto exit;
    }
skip_optional:
    return_value = fcntl_lockf_impl(module, fd, code, lenobj, startobj, whence);

exit:
    return return_value;
}
/*[clinic end generated code: output=1db859412172dd53 input=a9049054013a1b77]*/