mirror of
https://github.com/python/cpython.git
synced 2025-10-31 21:51:50 +00:00
341 lines
8.6 KiB
C
341 lines
8.6 KiB
C
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/* fcntl module */
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#include "Python.h"
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#ifdef HAVE_UNISTD_H
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#include <unistd.h>
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#endif
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#ifdef HAVE_SYS_FILE_H
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#include <sys/file.h>
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#endif
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#include <sys/ioctl.h>
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#include <fcntl.h>
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/* fcntl(fd, opt, [arg]) */
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static PyObject *
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fcntl_fcntl(PyObject *self, PyObject *args)
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{
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int fd;
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int code;
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int arg;
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int ret;
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char *str;
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int len;
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char buf[1024];
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if (PyArg_ParseTuple(args, "iis#:fcntl", &fd, &code, &str, &len)) {
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if (len > sizeof buf) {
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PyErr_SetString(PyExc_ValueError,
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"fcntl string arg too long");
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return NULL;
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}
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memcpy(buf, str, len);
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Py_BEGIN_ALLOW_THREADS
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ret = fcntl(fd, code, buf);
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Py_END_ALLOW_THREADS
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if (ret < 0) {
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PyErr_SetFromErrno(PyExc_IOError);
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return NULL;
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}
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return PyString_FromStringAndSize(buf, len);
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}
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PyErr_Clear();
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arg = 0;
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if (!PyArg_ParseTuple(args, "ii|i;fcntl requires 2 integers and optionally a third integer or a string",
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&fd, &code, &arg)) {
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return NULL;
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}
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Py_BEGIN_ALLOW_THREADS
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ret = fcntl(fd, code, arg);
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Py_END_ALLOW_THREADS
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if (ret < 0) {
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PyErr_SetFromErrno(PyExc_IOError);
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return NULL;
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}
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return PyInt_FromLong((long)ret);
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}
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static char fcntl_doc [] =
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"fcntl(fd, opt, [arg])\n\
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\n\
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Perform the requested operation on file descriptor fd. The operation\n\
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is defined by op and is operating system dependent. Typically these\n\
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codes can be retrieved from the library module FCNTL. The argument arg\n\
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is optional, and defaults to 0; it may be an int or a string. If arg is\n\
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given as a string, the return value of fcntl is a string of that length,\n\
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containing the resulting value put in the arg buffer by the operating system.\n\
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The length of the arg string is not allowed to exceed 1024 bytes. If the arg\n\
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given is an integer or if none is specified, the result value is an integer\n\
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corresponding to the return value of the fcntl call in the C code.";
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/* ioctl(fd, opt, [arg]) */
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static PyObject *
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fcntl_ioctl(PyObject *self, PyObject *args)
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{
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int fd;
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int code;
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int arg;
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int ret;
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char *str;
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int len;
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char buf[1024];
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if (PyArg_ParseTuple(args, "iis#:ioctl", &fd, &code, &str, &len)) {
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if (len > sizeof buf) {
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PyErr_SetString(PyExc_ValueError,
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"ioctl string arg too long");
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return NULL;
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}
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memcpy(buf, str, len);
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Py_BEGIN_ALLOW_THREADS
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ret = ioctl(fd, code, buf);
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Py_END_ALLOW_THREADS
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if (ret < 0) {
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PyErr_SetFromErrno(PyExc_IOError);
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return NULL;
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}
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return PyString_FromStringAndSize(buf, len);
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}
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PyErr_Clear();
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arg = 0;
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if (!PyArg_ParseTuple(args, "ii|i;ioctl requires 2 integers and optionally a third integer or a string",
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&fd, &code, &arg)) {
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return NULL;
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}
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Py_BEGIN_ALLOW_THREADS
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ret = ioctl(fd, code, arg);
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Py_END_ALLOW_THREADS
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if (ret < 0) {
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PyErr_SetFromErrno(PyExc_IOError);
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return NULL;
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}
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return PyInt_FromLong((long)ret);
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}
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static char ioctl_doc [] =
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"ioctl(fd, opt, [arg])\n\
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\n\
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Perform the requested operation on file descriptor fd. The operation\n\
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is defined by op and is operating system dependent. Typically these\n\
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codes can be retrieved from the library module IOCTL. The argument arg\n\
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is optional, and defaults to 0; it may be an int or a string. If arg is\n\
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given as a string, the return value of ioctl is a string of that length,\n\
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containing the resulting value put in the arg buffer by the operating system.\n\
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The length of the arg string is not allowed to exceed 1024 bytes. If the arg\n\
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given is an integer or if none is specified, the result value is an integer\n\
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corresponding to the return value of the ioctl call in the C code.";
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/* flock(fd, operation) */
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static PyObject *
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fcntl_flock(PyObject *self, PyObject *args)
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{
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int fd;
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int code;
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int ret;
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if (!PyArg_ParseTuple(args, "ii:flock", &fd, &code))
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return NULL;
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#ifdef HAVE_FLOCK
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Py_BEGIN_ALLOW_THREADS
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ret = flock(fd, code);
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Py_END_ALLOW_THREADS
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#else
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#ifndef LOCK_SH
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#define LOCK_SH 1 /* shared lock */
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#define LOCK_EX 2 /* exclusive lock */
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#define LOCK_NB 4 /* don't block when locking */
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#define LOCK_UN 8 /* unlock */
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#endif
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{
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struct flock l;
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if (code == LOCK_UN)
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l.l_type = F_UNLCK;
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else if (code & LOCK_SH)
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l.l_type = F_RDLCK;
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else if (code & LOCK_EX)
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l.l_type = F_WRLCK;
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else {
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PyErr_SetString(PyExc_ValueError,
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"unrecognized flock argument");
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return NULL;
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}
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l.l_whence = l.l_start = l.l_len = 0;
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Py_BEGIN_ALLOW_THREADS
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ret = fcntl(fd, (code & LOCK_NB) ? F_SETLK : F_SETLKW, &l);
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Py_END_ALLOW_THREADS
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}
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#endif /* HAVE_FLOCK */
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if (ret < 0) {
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PyErr_SetFromErrno(PyExc_IOError);
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return NULL;
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}
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Py_INCREF(Py_None);
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return Py_None;
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}
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static char flock_doc [] =
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"flock(fd, operation)\n\
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\n\
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Perform the lock operation op on file descriptor fd. See the Unix \n\
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manual flock(3) for details. (On some systems, this function is\n\
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emulated using fcntl().)";
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/* lockf(fd, operation) */
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static PyObject *
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fcntl_lockf(PyObject *self, PyObject *args)
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{
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int fd, code, ret, whence = 0;
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PyObject *lenobj = NULL, *startobj = NULL;
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if (!PyArg_ParseTuple(args, "ii|OOi:lockf", &fd, &code,
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&lenobj, &startobj, &whence))
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return NULL;
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#ifndef LOCK_SH
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#define LOCK_SH 1 /* shared lock */
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#define LOCK_EX 2 /* exclusive lock */
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#define LOCK_NB 4 /* don't block when locking */
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#define LOCK_UN 8 /* unlock */
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#endif
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{
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struct flock l;
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if (code == LOCK_UN)
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l.l_type = F_UNLCK;
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else if (code & LOCK_SH)
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l.l_type = F_RDLCK;
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else if (code & LOCK_EX)
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l.l_type = F_WRLCK;
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else {
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PyErr_SetString(PyExc_ValueError,
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"unrecognized flock argument");
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return NULL;
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}
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l.l_start = l.l_len = 0;
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if (startobj != NULL) {
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#if !defined(HAVE_LARGEFILE_SUPPORT)
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l.l_start = PyInt_AsLong(startobj);
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#else
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l.l_start = PyLong_Check(startobj) ?
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PyLong_AsLongLong(startobj) :
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PyInt_AsLong(startobj);
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#endif
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if (PyErr_Occurred())
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return NULL;
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}
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if (lenobj != NULL) {
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#if !defined(HAVE_LARGEFILE_SUPPORT)
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l.l_len = PyInt_AsLong(lenobj);
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#else
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l.l_len = PyLong_Check(lenobj) ?
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PyLong_AsLongLong(lenobj) :
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PyInt_AsLong(lenobj);
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#endif
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if (PyErr_Occurred())
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return NULL;
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}
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l.l_whence = whence;
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Py_BEGIN_ALLOW_THREADS
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ret = fcntl(fd, (code & LOCK_NB) ? F_SETLK : F_SETLKW, &l);
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Py_END_ALLOW_THREADS
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}
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if (ret < 0) {
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PyErr_SetFromErrno(PyExc_IOError);
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return NULL;
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}
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Py_INCREF(Py_None);
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return Py_None;
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}
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static char lockf_doc [] =
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"lockf (fd, operation, length=0, start=0, whence=0)\n\
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\n\
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This is essentially a wrapper around the fcntl() locking calls. fd is the\n\
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file descriptor of the file to lock or unlock, and operation is one of the\n\
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following values:\n\
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\n\
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LOCK_UN - unlock\n\
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LOCK_SH - acquire a shared lock\n\
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LOCK_EX - acquire an exclusive lock\n\
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\n\
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When operation is LOCK_SH or LOCK_EX, it can also be bit-wise OR'd with\n\
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LOCK_NB to avoid blocking on lock acquisition. If LOCK_NB is used and the\n\
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lock cannot be acquired, an IOError will be raised and the exception will\n\
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have an errno attribute set to EACCES or EAGAIN (depending on the operating\n\
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system -- for portability, check for either value).\n\
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\n\
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length is the number of bytes to lock, with the default meaning to lock to\n\
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EOF. start is the byte offset, relative to whence, to that the lock\n\
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starts. whence is as with fileobj.seek(), specifically:\n\
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\n\
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0 - relative to the start of the file (SEEK_SET)\n\
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1 - relative to the current buffer position (SEEK_CUR)\n\
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2 - relative to the end of the file (SEEK_END)";
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/* List of functions */
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static PyMethodDef fcntl_methods[] = {
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{"fcntl", fcntl_fcntl, METH_VARARGS, fcntl_doc},
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{"ioctl", fcntl_ioctl, METH_VARARGS, ioctl_doc},
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{"flock", fcntl_flock, METH_VARARGS, flock_doc},
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{"lockf", fcntl_lockf, METH_VARARGS, lockf_doc},
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{NULL, NULL} /* sentinel */
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};
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static char module_doc [] =
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"This module performs file control and I/O control on file \n\
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descriptors. It is an interface to the fcntl() and ioctl() Unix\n\
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routines. File descriptors can be obtained with the fileno() method of\n\
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a file or socket object.";
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/* Module initialisation */
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static int
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ins(PyObject* d, char* symbol, long value)
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{
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PyObject* v = PyInt_FromLong(value);
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if (!v || PyDict_SetItemString(d, symbol, v) < 0)
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return -1;
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Py_DECREF(v);
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return 0;
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}
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static int
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all_ins(PyObject* d)
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{
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if (ins(d, "LOCK_SH", (long)LOCK_SH)) return -1;
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if (ins(d, "LOCK_EX", (long)LOCK_EX)) return -1;
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if (ins(d, "LOCK_NB", (long)LOCK_NB)) return -1;
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if (ins(d, "LOCK_UN", (long)LOCK_UN)) return -1;
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return 0;
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}
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DL_EXPORT(void)
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initfcntl(void)
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{
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PyObject *m, *d;
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/* Create the module and add the functions and documentation */
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m = Py_InitModule3("fcntl", fcntl_methods, module_doc);
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/* Add some symbolic constants to the module */
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d = PyModule_GetDict(m);
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all_ins(d);
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}
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