[Pymoul-svn] SF.net SVN: pymoul: [198] pymoul/trunk/src/moul/osdependent/processinfo.py

[<ti...@us...>]

Revision: 198
          http://pymoul.svn.sourceforge.net/pymoul/?rev=198&view=rev
Author:   tiran
Date:     2007-02-26 19:01:53 -0800 (Mon, 26 Feb 2007)

Log Message:
-----------
Added ps parser to processinfo

Modified Paths:
--------------
    pymoul/trunk/src/moul/osdependent/processinfo.py

Modified: pymoul/trunk/src/moul/osdependent/processinfo.py
===================================================================
--- pymoul/trunk/src/moul/osdependent/processinfo.py	2007-02-26 17:43:35 UTC (rev 197)
+++ pymoul/trunk/src/moul/osdependent/processinfo.py	2007-02-27 03:01:53 UTC (rev 198)
@@ -17,6 +17,13 @@
 #
 """Get process informations
 
+The module contains for implementations:
+
+ - an Unsupported implementation that raises UnsupportedError
+ - a Linux implementation that read the data from /proc
+ - a Unix/POSIX implementation that parses the output of ps
+ - a Windows implementation that uses ctypes to get the infos from psapi.dll
+
 API
 ===
   getPids() - list of ints/longs
@@ -56,11 +63,9 @@
 LOG = getLogger("processinfo")
 
 _plat = sys.platform.startswith
-if _plat('linux'):
-    PLAT = 'linux'
-    import os.path
-elif _plat('win') or _plat('cygwin'):
-    PLAT = 'win'
+if _plat('win') or _plat('cygwin'):
+    LOG.debug("Using ctypes on Windows")
+    IMPL = 'win'
     from ctypes import windll, c_ulong, sizeof, c_buffer, byref
 
     PSAPI = windll.psapi
@@ -68,25 +73,147 @@
     PROCESS_QUERY_INFORMATION = 0x0400
     PROCESS_VM_READ = 0x0010
     PROCESS_FLAGS = PROCESS_QUERY_INFORMATION | PROCESS_VM_READ
-#elif _plat('darwin'):
-#    pass
 else:
-    raise OSError("OS %s is not supported" % os.name)
+    import os
+    PROC = '/proc'
+    if os.path.isfile("%s/self/status" % PROC):
+        LOG.debug("Using /proc on Linux")
+        IMPL = 'proc'
+    elif os.system('ps') == 0:
+        LOG.debug("Using the 'ps' command on POSIX os")
+        IMPL = 'ps'
+        from subprocess import Popen
+        from subprocess import PIPE
+    else:
+        LOG.warning("Unsupported OS. Neither /proc nor 'ps' works.")
+        IMPL = "unsupported"
 
 NULL = "\x00"
 
+class UnsupportedError(OSError):
+    pass
+
+class Unsupported(object):
+    """Unsupported OS
+    """
+    __slots__ = ()
+
+    def supported(self):
+        return False
+    supported = property(supported)
+
+    def getPids(self):
+        """Get a list of pids
+        """
+        raise UnsupportedError
+
+    def getPidNames(self):
+        """Get a list of pid -> name
+        """
+        raise UnsupportedError
+
+    def getPidDetails(self, pid):
+        """Get detailed informations about a process
+        """
+        raise UnsupportedError
+
+class PsParser(object):
+    """Parse the output of the ps command
+    """
+    __slots__ = ()
+
+    CMD = "ps -e --no-header --cols=1024"
+    PIDNAMES = "%s --format=pid,ucmd" % CMD
+    PIDS = "%s --format=pid" % CMD
+
+    def supported(self):
+        return False
+    supported = property(supported)
+
+    def getPids(self):
+        """Get a list of pids
+        """
+        stdout = self._exec(self.PIDS)
+        if stdout is None:
+            return None
+        pids = []
+        for line in stdout:
+            try:
+                pid = int(line.strip())
+            except ValueError:
+                pass
+            else:
+                pids.append(pid)
+        return pids
+
+    def getPidNames(self):
+        """Get a list of pid -> name
+        """
+        stdout = self._exec(self.PIDNAMES)
+        if stdout is None:
+            return None
+        mapping = {}
+        for line in stdout:
+            line = line.strip()
+            idx = line.find(' ')
+            pid, name = line[:idx], line[idx+1:]
+            try:
+                pid = int(pid)
+            except ValueError:
+                pass
+            else:
+                mapping[pid] = name
+        return mapping
+
+    def getPidDetails(self, pid):
+        """Get detailed informations about a process
+
+        TODO
+        """
+        raise UnsupportedError
+
+    def _exec(self, cmd):
+        """Execute command cmd
+
+        The method waits until the command has finished. It returns None of 
+        something went wrong.
+
+        @param cmd: Command to execute
+        @type cmd: str
+        @return: None or stdin as file like object
+        """
+        try:
+            popen = Popen(cmd, shell=True, bufsize=-1, stdout=PIPE,
+                          env = {'LC_ALL' : 'C'})
+            rc = popen.wait()
+        except (OSError, ValueError):
+            LOG.exception("Failed to execute '%s'" % cmd)
+            return None
+        else:
+            if rc != 0:
+                LOG.error("'%s' returned with error code %i" % (cmd, rc))
+                return None
+            else:
+                return popen.stdout
+
 class LinuxProcReader(object):
     """Get process informations under Linux by reading /proc
-    
+
     Tested under Linux, may work on other POSIX os with /proc, too.
     """
+    __slots__ = ()
 
-    def getPids(self):
+    def supported(self):
+        return True
+    supported = property(supported)
+
+    @staticmethod
+    def getPids():
         """Get a list of pids
         """
         pids = []
-        for name in os.listdir('/proc'):
-            if os.path.isdir('/proc/' + name):
+        for name in os.listdir(PROC):
+            if os.path.isdir(PROC + '/' + name):
                 try:
                     pids.append(int(name))
                 except ValueError:
@@ -113,9 +240,9 @@
 
     def _readProcStatus(self, pid, searchkey=None):
         """Read and parse status informations for PID pid
-        
+
         pid - pid as long or int or 'self'
-        
+
         If searchkey is None the method returns a mapping of lower keys
         to values (stripped).
         If searchkey is given than the method immediatly returns the value
@@ -124,7 +251,7 @@
         mapping = {}
         try:
             # read entiry file to avoid race conditions
-            lines = open('/proc/%s/status' % pid, 'r').readlines()
+            lines = open('%s/%i/status' % (PROC, pid), 'r').readlines()
         except IOError:
             return None
         for line in lines:
@@ -142,34 +269,40 @@
         if searchkey is not None:
             return None
         return mapping
-    
+
     def _readProcCmdline(self, pid):
         """Read cmdline informations for pid and returns a list similar to sys.argv
         """
         try:
             # read entiry file to avoid race conditions
-            data = open('/proc/%s/cmdline' % pid, 'r').read()
+            data = open('%s/%i/cmdline' % (PROC, pid), 'r').read()
         except IOError:
             return None
         return data.split(NULL)
 
     def _readProcOther(self, pid):
         """Read other possible useful things
-        
+
         cwd -> current work directory (may not exist)
         exe -> path to executable (may not exist)
         """
         return {
-            'cwd' : os.path.realpath('/proc/%s/cwd' % pid),
-            'exe' : os.path.realpath('/proc/%s/exe' % pid),
+            'cwd' : os.path.realpath('%s/%i/cwd' % (PROC, pid)),
+            'exe' : os.path.realpath('%s/%i/exe' % (PROC, pid)),
         }
 
 class WinEnumProcesses(object):
     """""Get process informations under Win32 with psapi.dll
-    
+
     Based on enumprocesses from Eric Koome 
     http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/305279
     """
+    __slots__ = ()
+
+    def supported(self):
+        return True
+    supported = property(supported)
+
     def getPids(self):
         """Get a list of pids
         """
@@ -214,32 +347,44 @@
         """
         if pid == 'self':
             pid = os.getpid()
-        
+
         hModule = c_ulong()
         count = c_ulong()
         modname = c_buffer(51)
         hProcess = KERNEL.OpenProcess(PROCESS_FLAGS, False, pid)
         if not hProcess:
             return None
-        
+
         PSAPI.EnumProcessModules(hProcess, byref(hModule),
                                  sizeof(hModule), byref(count))
         PSAPI.GetModuleBaseNameA(hProcess, hModule.value, modname,
                                  sizeof(modname))
-        name = u"".join([c for c in modname if c != NULL])
+        try:
+            name = u"".join([c for c in modname if c != NULL])
+        except UnicodeError, msg:
+            LOG.exception("Can't decode name of pid %i" % pid)
+        else:
+            name = None
+
         KERNEL.CloseHandle(hProcess)
         return {'name' : name}
 
 
 # Initialize global methods
-if PLAT == 'linux':
+if IMPL == 'proc':
     _enumProcesses = LinuxProcReader()
-elif PLAT == 'win':
+elif IMPL == 'ps':
+    _enumProcesses = PsParser()
+elif IMPL == 'win':
     _enumProcesses = WinEnumProcesses()
+else:
+    LOG.error("System %s is not supported" % sys.platform)
+    _enumProcesses = Unsupported()
 
 getPids = _enumProcesses.getPids
 getPidNames = _enumProcesses.getPidNames
 getPidDetails = _enumProcesses.getPidDetails
+supportedOS = _enumProcesses.supported
 
 if __name__ == '__main__':
     print getPidNames()


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