Fix for feature request #1528 Add os.fchmod

Georg Brandl has added fchmod() and fchown(). I've contributed lchown but I'm not able to test it on Linux. However it should be available on Mac and some other flavors of Unix.
I've made a quick test of fchmod() and fchown() on my system. They are working as expected.

5 files changed, 120 insertions, 5 deletions

diff --git a/Doc/library/os.rst b/Doc/library/os.rst
index 7d12488..4904ea0 100644
--- a/Doc/library/os.rst
+++ b/Doc/library/os.rst
@@ -523,6 +523,19 @@ by file descriptors.
    Availability: Macintosh, Unix, Windows.
 
 
+.. function:: fchmod(fd, mode)
+
+   Change the mode of the file given by *fd* to the numeric *mode*.  See the docs
+   for :func:`chmod` for possible values of *mode*.  Availability: Unix.
+
+
+.. function:: fchown(fd, uid, gid)
+
+   Change the owner and group id of the file given by *fd* to the numeric *uid*
+   and *gid*.  To leave one of the ids unchanged, set it to -1.
+   Availability: Unix.
+
+
 .. function:: fdatasync(fd)
 
    Force write of file with filedescriptor *fd* to disk. Does not force update of
@@ -581,6 +594,13 @@ by file descriptors.
    tty(-like) device, else ``False``. Availability: Macintosh, Unix.
 
 
+.. function:: lchmod(path, mode)
+
+   Change the mode of *path* to the numeric *mode*. If path is a symlink, this
+   affects the symlink rather than the target. See the docs for :func:`chmod`
+   for possible values of *mode*.  Availability: Unix.
+
+
 .. function:: lseek(fd, pos, how)
 
    Set the current position of file descriptor *fd* to position *pos*, modified by
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 5fcc521..ff79a0e 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -191,6 +191,12 @@ extern int chmod(const char *, int);
 #else
 extern int chmod(const char *, mode_t);
 #endif
+/*#ifdef HAVE_FCHMOD
+extern int fchmod(int, mode_t);
+#endif*/
+/*#ifdef HAVE_LCHMOD
+extern int lchmod(const char *, mode_t);
+#endif*/
 extern int chown(const char *, uid_t, gid_t);
 extern char *getcwd(char *, int);
 extern char *strerror(int);
@@ -1722,6 +1728,52 @@ posix_chmod(PyObject *self, PyObject *args)
 #endif
 }
 
+#ifdef HAVE_FCHMOD
+PyDoc_STRVAR(posix_fchmod__doc__,
+"fchmod(fd, mode)\n\n\
+Change the access permissions of the file given by file\n\
+descriptor fd.");
+
+static PyObject *
+posix_fchmod(PyObject *self, PyObject *args)
+{
+	int fd, mode, res;
+	if (!PyArg_ParseTuple(args, "ii:fchmod", &fd, &mode))
+		return NULL;
+	Py_BEGIN_ALLOW_THREADS
+	res = fchmod(fd, mode);
+	Py_END_ALLOW_THREADS
+	if (res < 0)
+		return posix_error();
+	Py_RETURN_NONE;
+}
+#endif /* HAVE_FCHMOD */
+
+#ifdef HAVE_LCHMOD
+PyDoc_STRVAR(posix_lchmod__doc__,
+"lchmod(path, mode)\n\n\
+Change the access permissions of a file. If path is a symlink, this\n\
+affects the link itself rather than the target.");
+
+static PyObject *
+posix_lchmod(PyObject *self, PyObject *args)
+{
+	char *path = NULL;
+	int i;
+	int res;
+	if (!PyArg_ParseTuple(args, "eti:lchmod", Py_FileSystemDefaultEncoding,
+	                      &path, &i))
+		return NULL;
+	Py_BEGIN_ALLOW_THREADS
+	res = lchmod(path, i);
+	Py_END_ALLOW_THREADS
+	if (res < 0)
+		return posix_error_with_allocated_filename(path);
+	PyMem_Free(path);
+	Py_RETURN_NONE;
+}
+#endif /* HAVE_LCHMOD */
+
 
 #ifdef HAVE_CHFLAGS
 PyDoc_STRVAR(posix_chflags__doc__,
@@ -1843,6 +1895,28 @@ posix_chown(PyObject *self, PyObject *args)
 }
 #endif /* HAVE_CHOWN */
 
+#ifdef HAVE_FCHOWN
+PyDoc_STRVAR(posix_fchown__doc__,
+"fchown(fd, uid, gid)\n\n\
+Change the owner and group id of the file given by file descriptor\n\
+fd to the numeric uid and gid.");
+
+static PyObject *
+posix_fchown(PyObject *self, PyObject *args)
+{
+	int fd, uid, gid;
+	int res;
+	if (!PyArg_ParseTuple(args, "iii:chown", &fd, &uid, &gid))
+		return NULL;
+	Py_BEGIN_ALLOW_THREADS
+	res = fchown(fd, (uid_t) uid, (gid_t) gid);
+	Py_END_ALLOW_THREADS
+	if (res < 0)
+		return posix_error();
+	Py_RETURN_NONE;
+}
+#endif /* HAVE_FCHOWN */
+
 #ifdef HAVE_LCHOWN
 PyDoc_STRVAR(posix_lchown__doc__,
 "lchown(path, uid, gid)\n\n\
@@ -8182,9 +8256,18 @@ static PyMethodDef posix_methods[] = {
 	{"chflags",	posix_chflags, METH_VARARGS, posix_chflags__doc__},
 #endif /* HAVE_CHFLAGS */
 	{"chmod",	posix_chmod, METH_VARARGS, posix_chmod__doc__},
+#ifdef HAVE_FCHMOD
+	{"fchmod",	posix_fchmod, METH_VARARGS, posix_fchmod__doc__},
+#endif /* HAVE_FCHMOD */
 #ifdef HAVE_CHOWN
 	{"chown",	posix_chown, METH_VARARGS, posix_chown__doc__},
 #endif /* HAVE_CHOWN */
+#ifdef HAVE_LCHMOD
+	{"lchmod",	posix_lchmod, METH_VARARGS, posix_lchmod__doc__},
+#endif /* HAVE_LCHMOD */
+#ifdef HAVE_FCHOWN
+	{"fchown",	posix_fchown, METH_VARARGS, posix_fchown__doc__},
+#endif /* HAVE_FCHOWN */
 #ifdef HAVE_LCHFLAGS
 	{"lchflags",	posix_lchflags, METH_VARARGS, posix_lchflags__doc__},
 #endif /* HAVE_LCHFLAGS */
diff --git a/configure b/configure
index 6beb47d..e116517 100755
--- a/configure
+++ b/configure
@@ -1,5 +1,5 @@
 #! /bin/sh
-# From configure.in Revision: 58653 .
+# From configure.in Revision: 58784 .
 # Guess values for system-dependent variables and create Makefiles.
 # Generated by GNU Autoconf 2.61 for python 2.6.
 #
@@ -15226,11 +15226,14 @@ echo "${ECHO_T}MACHDEP_OBJS" >&6; }
 
 
 
+
+
+
 for ac_func in alarm bind_textdomain_codeset chflags chown clock confstr \
- ctermid execv fork fpathconf ftime ftruncate \
+ ctermid execv fchmod fchown fork fpathconf ftime ftruncate \
  gai_strerror getgroups getlogin getloadavg getpeername getpgid getpid \
  getpriority getpwent getspnam getspent getsid getwd \
- kill killpg lchflags lchown lstat mkfifo mknod mktime \
+ kill killpg lchflags lchmod lchown lstat mkfifo mknod mktime \
  mremap nice pathconf pause plock poll pthread_init \
  putenv readlink realpath \
  select setegid seteuid setgid \
diff --git a/configure.in b/configure.in
index 5806912..4c6dee9 100644
--- a/configure.in
+++ b/configure.in
@@ -2304,10 +2304,10 @@ AC_MSG_RESULT(MACHDEP_OBJS)
 
 # checks for library functions
 AC_CHECK_FUNCS(alarm bind_textdomain_codeset chflags chown clock confstr \
- ctermid execv fork fpathconf ftime ftruncate \
+ ctermid execv fchmod fchown fork fpathconf ftime ftruncate \
  gai_strerror getgroups getlogin getloadavg getpeername getpgid getpid \
  getpriority getpwent getspnam getspent getsid getwd \
- kill killpg lchflags lchown lstat mkfifo mknod mktime \
+ kill killpg lchflags lchmod lchown lstat mkfifo mknod mktime \
  mremap nice pathconf pause plock poll pthread_init \
  putenv readlink realpath \
  select setegid seteuid setgid \
diff --git a/pyconfig.h.in b/pyconfig.h.in
index 16c85a5..1ba3e58 100644
--- a/pyconfig.h.in
+++ b/pyconfig.h.in
@@ -144,6 +144,12 @@
 /* Define if you have the 'fchdir' function. */
 #undef HAVE_FCHDIR
 
+/* Define to 1 if you have the `fchmod' function. */
+#undef HAVE_FCHMOD
+
+/* Define to 1 if you have the `fchown' function. */
+#undef HAVE_FCHOWN
+
 /* Define to 1 if you have the <fcntl.h> header file. */
 #undef HAVE_FCNTL_H
 
@@ -300,6 +306,9 @@
 /* Define to 1 if you have the `lchflags' function. */
 #undef HAVE_LCHFLAGS
 
+/* Define to 1 if you have the `lchmod' function. */
+#undef HAVE_LCHMOD
+
 /* Define to 1 if you have the `lchown' function. */
 #undef HAVE_LCHOWN