Rewrite using class, to make waiting for processes possible;
by default children are waited for automatically.
diff --git a/Lib/popen2.py b/Lib/popen2.py
index d2867c6..ae89f94 100644
--- a/Lib/popen2.py
+++ b/Lib/popen2.py
@@ -2,49 +2,97 @@
import sys
import string
-MAXFD = 100 # Max number of file descriptors (os.getdtablesize()???)
+MAXFD = 256 # Max number of file descriptors (os.getdtablesize()???)
-def _popen2(cmd, capturestderr=0):
+_active = []
+
+def _cleanup():
+ for inst in _active[:]:
+ inst.poll()
+
+class Popen3:
+ def __init__(self, cmd, capturestderr=0):
cmd = ['/bin/sh', '-c', cmd]
p2cread, p2cwrite = os.pipe()
c2pread, c2pwrite = os.pipe()
if capturestderr:
- errout, errin = os.pipe()
- pid = os.fork()
- if pid == 0:
- # Child
- os.close(0)
- os.close(1)
- if os.dup(p2cread) <> 0:
- sys.stderr.write('popen2: bad read dup\n')
- if os.dup(c2pwrite) <> 1:
- sys.stderr.write('popen2: bad write dup\n')
- if capturestderr:
- os.close(2)
- if os.dup(errin) <> 2: pass
- for i in range(3, MAXFD):
- try:
- os.close(i)
- except: pass
+ errout, errin = os.pipe()
+ self.pid = os.fork()
+ if self.pid == 0:
+ # Child
+ os.close(0)
+ os.close(1)
+ if os.dup(p2cread) <> 0:
+ sys.stderr.write('popen2: bad read dup\n')
+ if os.dup(c2pwrite) <> 1:
+ sys.stderr.write('popen2: bad write dup\n')
+ if capturestderr:
+ os.close(2)
+ if os.dup(errin) <> 2: pass
+ for i in range(3, MAXFD):
try:
- os.execv(cmd[0], cmd)
- finally:
- os._exit(1)
- # Shouldn't come here, I guess
+ os.close(i)
+ except: pass
+ try:
+ os.execv(cmd[0], cmd)
+ finally:
os._exit(1)
+ # Shouldn't come here, I guess
+ os._exit(1)
os.close(p2cread)
- tochild = os.fdopen(p2cwrite, 'w')
+ self.tochild = os.fdopen(p2cwrite, 'w')
os.close(c2pwrite)
- fromchild = os.fdopen(c2pread, 'r')
+ self.fromchild = os.fdopen(c2pread, 'r')
if capturestderr:
- os.close(errin)
- childerr = os.fdopen(errout, 'r')
- return fromchild, tochild, childerr
+ os.close(errin)
+ self.childerr = os.fdopen(errout, 'r')
else:
- return fromchild, tochild, None
+ self.childerr = None
+ self.sts = -1 # Child not completed yet
+ _active.append(self)
+ def poll(self):
+ 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):
+ pid, sts = os.waitpid(self.pid, 0)
+ if pid == self.pid:
+ self.sts = sts
+ _active.remove(self)
+ return self.sts
def popen2(cmd):
- return _popen2(cmd, 0)[:2]
+ _cleanup()
+ inst = Popen3(cmd, 0)
+ return inst.fromchild, inst.tochild
def popen3(cmd):
- return _popen2(cmd, 1)
+ _cleanup()
+ inst = Popen3(cmd, 1)
+ return inst.fromchild, inst.tochild, inst.childerr
+
+def _test():
+ teststr = "abc\n"
+ print "testing popen2..."
+ r, w = popen2('cat')
+ w.write(teststr)
+ w.close()
+ assert r.read() == teststr
+ print "testing popen3..."
+ r, w, e = popen3('cat')
+ w.write(teststr)
+ w.close()
+ assert r.read() == teststr
+ assert e.read() == ""
+ _cleanup()
+ assert not _active
+ print "All OK"
+
+if __name__ == '__main__':
+ _test()