diff options
Diffstat (limited to 'lib/jython/Lib/popen2.py')
| -rw-r--r-- | lib/jython/Lib/popen2.py | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/lib/jython/Lib/popen2.py b/lib/jython/Lib/popen2.py new file mode 100644 index 000000000..06199c47f --- /dev/null +++ b/lib/jython/Lib/popen2.py @@ -0,0 +1,198 @@ +"""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
+
+__all__ = ["popen2", "popen3", "popen4"]
+
+MAXFD = 256 # Max number of file descriptors (os.getdtablesize()???)
+
+_active = []
+
+def _cleanup():
+ for inst in _active[:]:
+ inst.poll()
+
+class Popen3:
+ """Class representing a child process. Normally instances are created
+ by the factory functions popen2() and popen3()."""
+
+ sts = -1 # Child not completed yet
+
+ def __init__(self, cmd, capturestderr=0, bufsize=-1):
+ """The parameter 'cmd' is the shell command to execute in a
+ sub-process. 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()
+ 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
+ _active.append(self)
+
+ def _run_child(self, cmd):
+ if type(cmd) == type(''):
+ cmd = ['/bin/sh', '-c', cmd]
+ for i in range(3, MAXFD):
+ try:
+ os.close(i)
+ except:
+ pass
+ try:
+ os.execvp(cmd[0], cmd)
+ finally:
+ os._exit(1)
+
+ def poll(self):
+ """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)
+ if pid == self.pid:
+ self.sts = sts
+ _active.remove(self)
+ except os.error:
+ pass
+ return self.sts
+
+ def wait(self):
+ """Wait for and return the exit status of the child process."""
+ pid, sts = os.waitpid(self.pid, 0)
+ if pid == self.pid:
+ self.sts = sts
+ _active.remove(self)
+ return self.sts
+
+
+class Popen4(Popen3):
+ childerr = None
+
+ def __init__(self, cmd, bufsize=-1):
+ _cleanup()
+ 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)
+ _active.append(self)
+
+
+if sys.platform[:3] == "win":
+ # 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. 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. 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. 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. 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, 0, bufsize)
+ return inst.fromchild, inst.tochild
+
+ def popen3(cmd, bufsize=-1, mode='t'):
+ """Execute the shell command 'cmd' in a sub-process. 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, 1, bufsize)
+ return inst.fromchild, inst.tochild, inst.childerr
+
+ def popen4(cmd, bufsize=-1, mode='t'):
+ """Execute the shell command 'cmd' in a sub-process. 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"])
+
+def _test():
+ cmd = "cat"
+ teststr = "ab cd\n"
+ if os.name == "nt":
+ cmd = "more"
+ # "more" doesn't act the same way across Windows flavors,
+ # sometimes adding an extra newline at the start or the
+ # end. So we strip whitespace off both ends for comparison.
+ expected = teststr.strip()
+ print "testing popen2..."
+ r, w = popen2(cmd)
+ w.write(teststr)
+ w.close()
+ got = r.read()
+ if got.strip() != expected:
+ raise ValueError("wrote %s read %s" % (`teststr`, `got`))
+ print "testing popen3..."
+ try:
+ r, w, e = popen3([cmd])
+ except:
+ r, w, e = popen3(cmd)
+ w.write(teststr)
+ w.close()
+ got = r.read()
+ if got.strip() != expected:
+ raise ValueError("wrote %s read %s" % (`teststr`, `got`))
+ got = e.read()
+ if got:
+ raise ValueError("unexected %s on stderr" % `got`)
+ for inst in _active[:]:
+ inst.wait()
+ if _active:
+ raise ValueError("_active not empty")
+ print "All OK"
+
+if __name__ == '__main__':
+ _test()
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