Use C code to redirect standard I/O streams for --detach and --daemonize

src/calibre/gui2/__init__.py

@@ -880,10 +880,10 @@ def detach_gui():
         if os.fork() != 0:
             raise SystemExit(0)
         os.setsid()
-        si, so, se = os.open(os.devnull, os.O_RDONLY), os.open(os.devnull, os.O_WRONLY), os.open(os.devnull, os.O_WRONLY)
+        try:
-        os.dup2(si, sys.__stdin__.fileno())
+            plugins['speedup'][0].detach(os.devnull)
-        os.dup2(so, sys.__stdout__.fileno())
+        except AttributeError:
-        os.dup2(se, sys.__stderr__.fileno())
+            pass  # people running from source without updated binaries
 
 class Application(QApplication):
 

src/calibre/library/server/main.py

@@ -10,7 +10,7 @@ from threading import Thread
 
 from calibre.library.server import server_config as config
 from calibre.library.server.base import LibraryServer
-from calibre.constants import iswindows
+from calibre.constants import iswindows, plugins
 import cherrypy
 
 def start_threaded_server(db, opts):
@@ -67,7 +67,7 @@ The OPDS interface is advertised via BonJour automatically.
                 ' work in all environments.'))
     return parser
 
-def daemonize(stdin='/dev/null', stdout='/dev/null', stderr='/dev/null'):
+def daemonize():
     try:
         pid = os.fork()
         if pid > 0:
@@ -93,12 +93,15 @@ def daemonize(stdin='/dev/null', stdout='/dev/null', stderr='/dev/null'):
         sys.exit(1)
 
     # Redirect standard file descriptors.
-    si = file(stdin, 'r')
+    try:
-    so = file(stdout, 'a+')
+        plugins['speedup'][0].detach(os.devnull)
-    se = file(stderr, 'a+', 0)
+    except AttributeError:  # people running from source without updated binaries
-    os.dup2(si.fileno(), sys.stdin.fileno())
+        si = os.open(os.devnull, os.O_RDONLY)
-    os.dup2(so.fileno(), sys.stdout.fileno())
+        so = os.open(os.devnull, os.O_WRONLY)
-    os.dup2(se.fileno(), sys.stderr.fileno())
+        se = os.open(os.devnull, os.O_WRONLY)
+        os.dup2(si, sys.stdin.fileno())
+        os.dup2(so, sys.stdout.fileno())
+        os.dup2(se, sys.stderr.fileno())
 
 
 def main(args=sys.argv):

src/calibre/utils/speedup.c

@@ -3,6 +3,7 @@
 
 #include <stdlib.h>
 #include <fcntl.h>
+#include <stdio.h>
 
 #define min(x, y) ((x < y) ? x : y)
 #define max(x, y) ((x > y) ? x : y)
@@ -97,6 +98,16 @@ speedup_pdf_float(PyObject *self, PyObject *args) {
     return ret;
 }
 
+static PyObject*
+speedup_detach(PyObject *self, PyObject *args) {
+    char *devnull = NULL;
+    if (!PyArg_ParseTuple(args, "s", &devnull)) return NULL;
+    if (freopen(devnull, "r", stdin) == NULL) return PyErr_SetFromErrno(PyExc_EnvironmentError);
+    if (freopen(devnull, "w", stdout) == NULL) return PyErr_SetFromErrno(PyExc_EnvironmentError);
+    if (freopen(devnull, "w", stderr) == NULL)  return PyErr_SetFromErrno(PyExc_EnvironmentError);
+    Py_RETURN_NONE;
+}
+
 static PyMethodDef speedup_methods[] = {
     {"parse_date", speedup_parse_date, METH_VARARGS,
         "parse_date()\n\nParse ISO dates faster."
@@ -106,6 +117,10 @@ static PyMethodDef speedup_methods[] = {
         "pdf_float()\n\nConvert float to a string representation suitable for PDF"
     },
 
+    {"detach", speedup_detach, METH_VARARGS,
+        "detach()\n\nRedirect the standard I/O stream to the specified file (usually os.devnull)"
+    },
+
     {NULL, NULL, 0, NULL}
 };