symbian-qemu-0.9.1-12/python-2.6.1/Lib/popen2.py
changeset 1 2fb8b9db1c86
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/symbian-qemu-0.9.1-12/python-2.6.1/Lib/popen2.py	Fri Jul 31 15:01:17 2009 +0100
@@ -0,0 +1,201 @@
+"""Spawn a command with pipes to its stdin, stdout, and optionally stderr.
+
+The normal os.popen(cmd, mode) call spawns a shell command and provides a
+file interface to just the input or output of the process depending on
+whether mode is 'r' or 'w'.  This module provides the functions popen2(cmd)
+and popen3(cmd) which return two or three pipes to the spawned command.
+"""
+
+import os
+import sys
+import warnings
+warnings.warn("The popen2 module is deprecated.  Use the subprocess module.",
+              DeprecationWarning, stacklevel=2)
+
+__all__ = ["popen2", "popen3", "popen4"]
+
+try:
+    MAXFD = os.sysconf('SC_OPEN_MAX')
+except (AttributeError, ValueError):
+    MAXFD = 256
+
+_active = []
+
+def _cleanup():
+    for inst in _active[:]:
+        if inst.poll(_deadstate=sys.maxint) >= 0:
+            try:
+                _active.remove(inst)
+            except ValueError:
+                # This can happen if two threads create a new Popen instance.
+                # It's harmless that it was already removed, so ignore.
+                pass
+
+class Popen3:
+    """Class representing a child process.  Normally, instances are created
+    internally by the functions popen2() and popen3()."""
+
+    sts = -1                    # Child not completed yet
+
+    def __init__(self, cmd, capturestderr=False, bufsize=-1):
+        """The parameter 'cmd' is the shell command to execute in a
+        sub-process.  On UNIX, 'cmd' may be a sequence, in which case arguments
+        will be passed directly to the program without shell intervention (as
+        with os.spawnv()).  If 'cmd' is a string it will be passed to the shell
+        (as with os.system()).   The 'capturestderr' flag, if true, specifies
+        that the object should capture standard error output of the child
+        process.  The default is false.  If the 'bufsize' parameter is
+        specified, it specifies the size of the I/O buffers to/from the child
+        process."""
+        _cleanup()
+        self.cmd = cmd
+        p2cread, p2cwrite = os.pipe()
+        c2pread, c2pwrite = os.pipe()
+        if capturestderr:
+            errout, errin = os.pipe()
+        self.pid = os.fork()
+        if self.pid == 0:
+            # Child
+            os.dup2(p2cread, 0)
+            os.dup2(c2pwrite, 1)
+            if capturestderr:
+                os.dup2(errin, 2)
+            self._run_child(cmd)
+        os.close(p2cread)
+        self.tochild = os.fdopen(p2cwrite, 'w', bufsize)
+        os.close(c2pwrite)
+        self.fromchild = os.fdopen(c2pread, 'r', bufsize)
+        if capturestderr:
+            os.close(errin)
+            self.childerr = os.fdopen(errout, 'r', bufsize)
+        else:
+            self.childerr = None
+
+    def __del__(self):
+        # In case the child hasn't been waited on, check if it's done.
+        self.poll(_deadstate=sys.maxint)
+        if self.sts < 0:
+            if _active is not None:
+                # Child is still running, keep us alive until we can wait on it.
+                _active.append(self)
+
+    def _run_child(self, cmd):
+        if isinstance(cmd, basestring):
+            cmd = ['/bin/sh', '-c', cmd]
+        os.closerange(3, MAXFD)
+        try:
+            os.execvp(cmd[0], cmd)
+        finally:
+            os._exit(1)
+
+    def poll(self, _deadstate=None):
+        """Return the exit status of the child process if it has finished,
+        or -1 if it hasn't finished yet."""
+        if self.sts < 0:
+            try:
+                pid, sts = os.waitpid(self.pid, os.WNOHANG)
+                # pid will be 0 if self.pid hasn't terminated
+                if pid == self.pid:
+                    self.sts = sts
+            except os.error:
+                if _deadstate is not None:
+                    self.sts = _deadstate
+        return self.sts
+
+    def wait(self):
+        """Wait for and return the exit status of the child process."""
+        if self.sts < 0:
+            pid, sts = os.waitpid(self.pid, 0)
+            # This used to be a test, but it is believed to be
+            # always true, so I changed it to an assertion - mvl
+            assert pid == self.pid
+            self.sts = sts
+        return self.sts
+
+
+class Popen4(Popen3):
+    childerr = None
+
+    def __init__(self, cmd, bufsize=-1):
+        _cleanup()
+        self.cmd = cmd
+        p2cread, p2cwrite = os.pipe()
+        c2pread, c2pwrite = os.pipe()
+        self.pid = os.fork()
+        if self.pid == 0:
+            # Child
+            os.dup2(p2cread, 0)
+            os.dup2(c2pwrite, 1)
+            os.dup2(c2pwrite, 2)
+            self._run_child(cmd)
+        os.close(p2cread)
+        self.tochild = os.fdopen(p2cwrite, 'w', bufsize)
+        os.close(c2pwrite)
+        self.fromchild = os.fdopen(c2pread, 'r', bufsize)
+
+
+if sys.platform[:3] == "win" or sys.platform == "os2emx":
+    # Some things don't make sense on non-Unix platforms.
+    del Popen3, Popen4
+
+    def popen2(cmd, bufsize=-1, mode='t'):
+        """Execute the shell command 'cmd' in a sub-process. On UNIX, 'cmd' may
+        be a sequence, in which case arguments will be passed directly to the
+        program without shell intervention (as with os.spawnv()). If 'cmd' is a
+        string it will be passed to the shell (as with os.system()). If
+        'bufsize' is specified, it sets the buffer size for the I/O pipes. The
+        file objects (child_stdout, child_stdin) are returned."""
+        w, r = os.popen2(cmd, mode, bufsize)
+        return r, w
+
+    def popen3(cmd, bufsize=-1, mode='t'):
+        """Execute the shell command 'cmd' in a sub-process. On UNIX, 'cmd' may
+        be a sequence, in which case arguments will be passed directly to the
+        program without shell intervention (as with os.spawnv()). If 'cmd' is a
+        string it will be passed to the shell (as with os.system()). If
+        'bufsize' is specified, it sets the buffer size for the I/O pipes. The
+        file objects (child_stdout, child_stdin, child_stderr) are returned."""
+        w, r, e = os.popen3(cmd, mode, bufsize)
+        return r, w, e
+
+    def popen4(cmd, bufsize=-1, mode='t'):
+        """Execute the shell command 'cmd' in a sub-process. On UNIX, 'cmd' may
+        be a sequence, in which case arguments will be passed directly to the
+        program without shell intervention (as with os.spawnv()). If 'cmd' is a
+        string it will be passed to the shell (as with os.system()). If
+        'bufsize' is specified, it sets the buffer size for the I/O pipes. The
+        file objects (child_stdout_stderr, child_stdin) are returned."""
+        w, r = os.popen4(cmd, mode, bufsize)
+        return r, w
+else:
+    def popen2(cmd, bufsize=-1, mode='t'):
+        """Execute the shell command 'cmd' in a sub-process. On UNIX, 'cmd' may
+        be a sequence, in which case arguments will be passed directly to the
+        program without shell intervention (as with os.spawnv()). If 'cmd' is a
+        string it will be passed to the shell (as with os.system()). If
+        'bufsize' is specified, it sets the buffer size for the I/O pipes. The
+        file objects (child_stdout, child_stdin) are returned."""
+        inst = Popen3(cmd, False, bufsize)
+        return inst.fromchild, inst.tochild
+
+    def popen3(cmd, bufsize=-1, mode='t'):
+        """Execute the shell command 'cmd' in a sub-process. On UNIX, 'cmd' may
+        be a sequence, in which case arguments will be passed directly to the
+        program without shell intervention (as with os.spawnv()). If 'cmd' is a
+        string it will be passed to the shell (as with os.system()). If
+        'bufsize' is specified, it sets the buffer size for the I/O pipes. The
+        file objects (child_stdout, child_stdin, child_stderr) are returned."""
+        inst = Popen3(cmd, True, bufsize)
+        return inst.fromchild, inst.tochild, inst.childerr
+
+    def popen4(cmd, bufsize=-1, mode='t'):
+        """Execute the shell command 'cmd' in a sub-process. On UNIX, 'cmd' may
+        be a sequence, in which case arguments will be passed directly to the
+        program without shell intervention (as with os.spawnv()). If 'cmd' is a
+        string it will be passed to the shell (as with os.system()). If
+        'bufsize' is specified, it sets the buffer size for the I/O pipes. The
+        file objects (child_stdout_stderr, child_stdin) are returned."""
+        inst = Popen4(cmd, bufsize)
+        return inst.fromchild, inst.tochild
+
+    __all__.extend(["Popen3", "Popen4"])