Why is pexpect acting funny with sendline() and expect()?
I am running Solaris 5-10, python 2.6.2 and pexpect 2.4 I have the very simple python script below which exercises the functionality of sending and receiving text from the shell. My understanding is that pexepect([pexpect.TIMEOUT, x,y,z], timeout=w) will return the index of the match that it found *since the last time pexpect was called*, but if it takes longer than w seconds, it will return 0. Here is my very simple script: #!/usr/bin/env python import pexpect myPrompt = % myShell = pexpect.spawn(/bin/tcsh) print Sending 'JUNK-0' to shell x = myShell.sendline(JUNK-0) y = myShell.expect([pexpect.TIMEOUT], timeout=1) print y = %s % y print myShell.before print = * 80 print \n\n for i in range(2): print i = %d % (i+1) print Sending 'JUNK-%d' to shell % (i+1) x = myShell.sendline(JUNK-%d % (i+1)) y = myShell.expect([pexpect.TIMEOUT, myPrompt], timeout=10) print y = %s % y print myShell.before print = * 80 print \n\n FYI, my shell prompt is myMachine % , however in this script I have simply used % to keep it generic. When I run it, I see the following output: Sending 'JUNK-0' to shell y = 0 JUNK-0 myMachine % JUNK-0 JUNK-0: Command not found. myMachine % i = 1 Sending 'JUNK-1' to shell y = 1 JUNK-0 myMachine i = 2 Sending 'JUNK-2' to shell y = 1 JUNK-0 JUNK-0: Command not found. myMachine Why do I see JUNK-0 consistently recurring in the output? It should be consumed by the first myShell.expect() statement, but it keeps showing up. Why?? -- http://mail.python.org/mailman/listinfo/python-list
Why does os.stat() tell me that my file-group has no members?
I'm using python 2.6.4 on Solaris 5-10. I have a file named myFile. It is owned by someone else, by I (myuser) am in the file's group (mygrp). Below is my python code. Why does it tell me that mygrp has no members??? import os, pwd, grp stat_info = os.stat(myFile) fileUID = stat_info.st_uid fileGID = stat_info.st_gid fileGroup = grp.getgrgid(fileGID)[0] fileUser = pwd.getpwuid(fileUID)[0] print grp.getgrgid(fileGID) = %s % grp.getgrgid(fileGID) grp.getgrgid(fileGID) = grp.struct_group(gr_name='mygrp', gr_passwd='', gr_gid=100, gr_mem=[]) -- http://mail.python.org/mailman/listinfo/python-list
Re: Why does os.stat() tell me that my file-group has no members?
Thanks!! This was very helpful. It worked perfectly. I had no clue about the intricacies of how python represents the group data from the underlying OS. This page doesn't go into to detailed explanation like you did: http://docs.python.org/2/library/grp.html On Wednesday, December 19, 2012 6:17:16 PM UTC-5, Hans Mulder wrote: On 19/12/12 22:40:00, saqib.ali...@gmail.com wrote: I'm using python 2.6.4 on Solaris 5-10. I have a file named myFile. It is owned by someone else, by I (myuser) am in the file's group (mygrp). Below is my python code. Why does it tell me that mygrp has no members??? import os, pwd, grp stat_info = os.stat(myFile) fileUID = stat_info.st_uid fileGID = stat_info.st_gid fileGroup = grp.getgrgid(fileGID)[0] fileUser = pwd.getpwuid(fileUID)[0] print grp.getgrgid(fileGID) = %s % grp.getgrgid(fileGID) grp.getgrgid(fileGID) = grp.struct_group(gr_name='mygrp', gr_passwd='', gr_gid=100, gr_mem=[]) It doesn't say that your group has no members. Every account has a primary group, and some accounts also have addtional groups. The primary group is the one in the .pw_gid attribute in the pwd entry. The additional groups are those that mention the account in the .gr_mem attribute in their grp entry. Your experiment shows that nobody has mygrp as an additional group. So if you're a member of mygrp, then it must be your primary group, i.e. os.getgid() should return 100 for you. You can get a complete list of members of group by adding two lists: def all_members(gid): primary_members = [ user.pw_name for user in pwd.getpwall() if user.pw_gid == gid ] additional_members = grp.getgrgid(gid).gr_mem return primary_members + additional_members Hope this helps, -- HansM -- http://mail.python.org/mailman/listinfo/python-list
Problem while doing a cat on a tabbed file with pexpect
I am using Solaris 10, python 2.6.2, pexpect 2.4 I create a file called me.txt which contains the letters A, B, C on the same line separated by tabs. My shell prompt is % I then do the following in the python shell: import pexpect x = pexpect.spawn(/bin/tcsh) x.sendline(cat me.txt) 11 x.expect([pexpect.TIMEOUT, % ]) 1 x.before 'cat me.txt\r\r\nA B C\r\n' x.before.split(\t) ['cat me.txt\r\r\nA B C\r\n'] Now, clearly the file contains tabs. But when I cat it through expect, and collect cat's output, those tabs have been converted to spaces. But I need the tabs! Can anyone explain this phenomenon or suggest how I can fix it? -- http://mail.python.org/mailman/listinfo/python-list
Re: Problem while doing a cat on a tabbed file with pexpect
Very good question. Let me explain why I'm not opening me.txt directly in python with open. The example I have posted is simplified for illustrative purpose. In reality, I'm not doing pexpect.spawn(/bin/tcsh). I'm doing pexpect.spawn(ssh myuser@ipaddress). Since I'm operating on a remote system, I can't simply open the file in my own python context. On Jan 15, 2:24 pm, Dennis Lee Bieber wlfr...@ix.netcom.com wrote: On Sun, 15 Jan 2012 09:51:44 -0800 (PST), Saqib Ali saqib.ali...@gmail.com wrote: Now, clearly the file contains tabs. But when I cat it through expect, and collect cat's output, those tabs have been converted to spaces. But I need the tabs! Can anyone explain this phenomenon or suggest how I can fix it? My question is: WHY are you doing this? Based upon the problem discription, as given, the solution would seem to be to just open the file IN Python -- whether you read the lines and use split() by hand, or pass the open file to the csv module for reading/parsing is up to you. -=-=-=-=-=-=- import csv import os TESTFILE = Test.tsv #create data file fout = open(TESTFILE, w) for ln in [ abc, defg, hijA ]: fout.write(\t.join(list(ln)) + \n) fout.close() #process tab-separated data fin = open(TESTFILE, rb) rdr = csv.reader(fin, dialect=excel-tab) for rw in rdr: print rw fin.close() del rdr os.remove(TESTFILE) -=-=-=-=-=-=- ['a', 'b', 'c'] ['d', 'e', 'f', 'g'] ['h', 'i', 'j', 'A'] -- Wulfraed Dennis Lee Bieber AF6VN wlfr...@ix.netcom.com HTTP://wlfraed.home.netcom.com/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Problem while doing a cat on a tabbed file with pexpect
The file me.txt does indeed contain tabs. I created it with vi.
text = open(me.txt, r).read()
print \t in text
True
% od -c me.txt
000 A \t B \t C \n
006
% ls -al me.txt
-rw-r--r-- 1 myUsermyGroup 6 Jan 15 12:42 me.txt
On Jan 15, 6:40 pm, Cameron Simpson c...@zip.com.au wrote:
On 15Jan2012 23:04, Steven D'Aprano steve+comp.lang.pyt...@pearwood.info
wrote:
| On Sun, 15 Jan 2012 09:51:44 -0800, Saqib Ali wrote:
| I am using Solaris 10, python 2.6.2, pexpect 2.4
|
| I create a file called me.txt which contains the letters A, B, C
| on the same line separated by tabs.
| [...]
| Now, clearly the file contains tabs.
|
| That is not clear at all. How do you know it contains tabs? How was the
| file created in the first place?
|
| Try this:
|
| text = open('me.txt', 'r').read()
| print '\t' in text
|
| My guess is that it will print False and that the file does not contain
| tabs. Check your editor used to create the file.
I was going to post an alternative theory but on more thought I think
Steven is right here.
What does:
od -c me.txt
show you? TABs or multiple spaces?
What does:
ls -ld me.txt
tell you about the file size? Is it 6 bytes long (three letters, two
TABs, one newline)?
Steven hasn't been explicit about it, but some editors will write spaces when
you type a TAB. I have configured mine to do so - it makes indentation more
reliable for others. If I really need a TAB character I have a special
finger contortion to get one, but the actual need is rare.
So first check that the file really does contain TABs.
Cheers,
--
Cameron Simpson c...@zip.com.au DoD#743http://www.cskk.ezoshosting.com/cs/
Yes Officer, yes Officer, I will Officer. Thank you.
--
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Changing the system clock with pexpect confuses pexpect!
See my code below.
I'm controlling a shell logged in as root with pexpect.
The class below has a method (startProc) which spawns a shell and
keeps it alive until told to destroy it (stopProc).
The other 2 methods in this class allow me to change the system clock
and to get the IP Address of this machine.
They all work fine except when I advance the system clock, and
then try to get the IP Address.
In that case, I get an exception because pexpect incorrectly thinks
the output it is getting from ifconfig is invalid. But it is not.
Pexpect is just confused. This doesn't happen when I move the clock
backwards. It only happens when I move the clock forward.
I believe what is going on is that internally pexpect uses the system
clock to keep track of when it receives data from spawned processes.
When I mess with the clock, that messes up the internal workings of
pexpect.
Any suggestions what I should do? I have numerous concurrent pexpect
processes running when I modify the clock. Is there anyway to prevent
them all from getting totally screwed up??
-
#!/usr/bin/env python
import pexpect, os, time, datetime, re
def reportPrint(string):
print string
def reportAssert(condition, string)
if condition == False:
print string
raise Exception
class rootManager:
rootProc = None
rootPrompt = ] %
myPrompt = ] %
def __init__(self):
pass
def startProc(self):
if self.rootProc != None:
reportPrint(\t\t- Root Process is already created)
else:
self.rootProc = pexpect.spawn ('/bin/tcsh',)
i = self.rootProc.expect([pexpect.TIMEOUT,
self.myPrompt,])
reportAssert(i != 0, Time-Out exiting)
reportPrint(\t\t- Sending su)
self.rootProc.sendline(su)
i = self.rootProc.expect([pexpect.TIMEOUT, Password: ,])
reportAssert(i != 0, Time-Out exiting)
reportPrint(\t\t- Sending Password)
self.rootProc.sendline(ROOT_PASSWORD)
i = self.rootProc.expect([pexpect.TIMEOUT,
self.rootPrompt,])
reportAssert(i != 0, Time-Out exiting)
reportPrint(\t\t- Root Process created)
def getIPAddr(self):
reportAssert(self.rootProc != None, No active Root Process!)
reportPrint(\t\t- Sending ifconfig -a)
self.rootProc.sendline(ifconfig -a)
i = self.rootProc.expect([pexpect.TIMEOUT, self.rootPrompt,])
reportAssert(i != 0, Time-Out exiting)
outputTxt = self.rootProc.before
ipList = [i for i in re.compile((?=inet )\d{1,3}\.\d{1,3}\.
\d{1,3}\.\d{1,3}).findall(outputTxt) if i != 127.0.0.1]
reportAssert(len(ipList) == 1, Cannot determine IP Address
from 'ifconfig -a': \n%s % outputTxt)
return ipList[0]
def changeClock(self, secondsDelta):
reportAssert(self.rootProc != None, No active Root Process!)
newTime = datetime.datetime.now() +
datetime.timedelta(seconds=secondsDelta)
dateStr = %02d%02d%02d%02d%s % (newTime.month, newTime.day,
newTime.hour, newTime.minute, str(newTime.year)[-2:])
reportPrint(\t\t- Sending 'date %s' command % dateStr)
self.rootProc.sendline(date %s % dateStr)
#Remember, by changing the clock, you are confusing pexpect's
timeout measurement!
# so ignore timeouts in this case
i = self.rootProc.expect([pexpect.TIMEOUT,
self.rootPrompt,],)
def stopProc(self):
if self.rootProc == None:
reportPrint(\t\t- Root Process is already destroyed)
else:
reportPrint(\t\t- Sending exit command)
rootProc.sendline(exit)
i = rootProc.expect([pexpect.TIMEOUT, self.myPrompt])
reportAssert(i != 0, Time-Out exiting)
reportPrint(\t\t- Sending exit command)
rootProc.sendline(exit)
i = rootProc.expect([pexpect.TIMEOUT, pexpect.EOF])
reportAssert(i != 0, Time-Out exiting)
self.rootProc.close()
self.rootProc = None
reportPrint(\t\t- Root Process Destroyed)
--
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Can't I define a decorator in a separate file and import it?
I'm using this decorator to implement singleton class in python: http://stackoverflow.com/posts/7346105/revisions The strategy described above works if and only if the Singleton is declared and defined in the same file. If it is defined in a different file and I import that file, it doesn't work. Why can't I import this Singleton decorator from a different file? What's the best work around? -- http://mail.python.org/mailman/listinfo/python-list
Re: Can't I define a decorator in a separate file and import it?
MYCLASS.PY: #!/usr/bin/env python import os, sys, string, time, re, subprocess import Singleton @Singleton class myClass: def __init__(self): print 'Constructing myClass' def __del__(self): print 'Destructing myClass' SINGLETON.PY: #!/usr/bin/env python import os, sys, string, time, re, subprocess import Singleton @Singleton class myClass: def __init__(self): print 'Constructing myClass' def __del__(self): print 'Destructing myClass' TRACEBACK: import myClass Traceback (most recent call last): File stdin, line 1, in module File myClass.py, line 6, in module @Singleton TypeError: 'module' object is not callable - Saqib Post the code, and the traceback. ~Ethan~ -- http://mail.python.org/mailman/listinfo/python-list
Re: Can't I define a decorator in a separate file and import it?
BTW Here is the traceback: import myClass Traceback (most recent call last): File stdin, line 1, in module File myClass.py, line 6, in module @Singleton TypeError: 'module' object is not callable Here is Singleton.py: class Singleton: def __init__(self, decorated): self._decorated = decorated def Instance(self): try: return self._instance except AttributeError: self._instance = self._decorated() return self._instance def __call__(self): raise TypeError( 'Singletons must be accessed through the `Instance` method.') Here is myClass.py: #!/usr/bin/env python import os, sys, string, time, re, subprocess import Singleton @Singleton class myClass: def __init__(self): print 'Constructing myClass' def __del__(self): print 'Destructing myClass' -- http://mail.python.org/mailman/listinfo/python-list
Re: Can't I define a decorator in a separate file and import it?
Thanks for pointing out the mistake! Works. - Saqib On Thu, Dec 22, 2011 at 4:31 PM, Ethan Furman et...@stoneleaf.us wrote: Saqib Ali wrote: MYCLASS.PY: #!/usr/bin/env python import os, sys, string, time, re, subprocess import Singleton This should be 'from Singleton import Singleton' @Singleton class myClass: def __init__(self): print 'Constructing myClass' At this point, the *instance* of myClass has already been constructed and it is now being initialized. The __new__ method is where the instance is actually created. def __del__(self): print 'Destructing myClass' class Singleton: def __init__(self, decorated): self._decorated = decorated def Instance(self): try: return self._instance except AttributeError: self._instance = self._decorated() return self._instance def __call__(self): raise TypeError( 'Singletons must be accessed through the `Instance` method.') ~Ethan~ -- http://mail.python.org/mailman/listinfo/python-list
Can I get use pexpect to control this process?
I have a program X that constantly spews output, hundreds of lines per minute. X is not an interactive program. IE: it doesn't take any user input. It just produces a lot of textual output to STDOUT. I would like to save the output produced by X into a different file every 5 seconds regardless of the actual content. I want one file to contain the output from seconds 0-5, another file should contain 6-10, etc. etc. Can I do this with pexpect? I'm not sure I can because the before argument gives me EVERYTHING upto the most recent match. What I really need is something that will give me what was produced between the last 2 calls to pexpect.expect(). -- http://mail.python.org/mailman/listinfo/python-list
Re: Need help with really elementary pexpect fragment
Oops! Good call.
Thank you. You pointed out my mistake.
- Saqib
On Tue, Dec 20, 2011 at 12:31 AM, Nick Dokos nicholas.do...@hp.com wrote:
Saqib Ali saqib.ali...@gmail.com wrote:
I want to write a pexpect script that simply cd's into a directory (~/
install) and then runs a command from there. It should be so easy.
But even my cd command is failing. Can't figure out what the problem
is. The command line prompt is [my machine name here] %
Here is the code fragment:
print Spawning Expect
p = pexpect.spawn ('/bin/tcsh',)
If you execute /bin/tcsh by hand, do you get a % prompt?
Nick
print Sending cd command
i = p.expect([pexpect.TIMEOUT, %,])
assert i != 0, Time-Out exiting
p.sendline(cd ~/install)
Here is the output:
Spawning Expect
Sending cd command
Time-Out exiting
How could I be screwing something so simple up??
--
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--
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Need help with really elementary pexpect fragment
I want to write a pexpect script that simply cd's into a directory (~/
install) and then runs a command from there. It should be so easy.
But even my cd command is failing. Can't figure out what the problem
is. The command line prompt is [my machine name here] %
Here is the code fragment:
print Spawning Expect
p = pexpect.spawn ('/bin/tcsh',)
print Sending cd command
i = p.expect([pexpect.TIMEOUT, %,])
assert i != 0, Time-Out exiting
p.sendline(cd ~/install)
Here is the output:
Spawning Expect
Sending cd command
Time-Out exiting
How could I be screwing something so simple up??
--
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Inexplicable behavior in simple example of a set in a class
I have written two EXTREMELY simple python classes. One class (myClass1) contains a data attribute (myNum) that contains an integer. The other class (myClass2) contains a data attribute (mySet) that contains a set. I instantiate 2 instances of myClass1 (a b). I then change the value of a.myNum. It works as expected. Then I instantiate 2 instances of myClass2 (c d). I then change the value of c.mySet. Bizarrely changing the value of c.mySet also affects the value of d.mySet which I haven't touched at all!?!?! Can someone explain this very strange behavior to me? I can't understand it for the life of me. Please see below the source code as well as the output. -- SOURCE CODE -- import sets class myClass1: myNum = 9 def clearNum(self): self.myNum = 0 def __str__(self): return str(self.myNum) class myClass2: mySet = sets.Set(range(1,10)) def clearSet(self): self.mySet.clear() def __str__(self): return str(len(self.mySet)) if __name__ == __main__: # Experiment 1. Modifying values of member integers in two different instances of a class # Works as expected. a = myClass1() b = myClass1() print a = %s % str(a) print b = %s % str(b) print a.clearNum() a.clearNum() print a = %s % str(a) print b = %s\n\n\n % str(b) # Experiment 2. Modifying values of member sets in two different instances of a class # Fails Unexplicably. d is not being modified. Yet calling c.clearSet() seems to change d.mySet's value c = myClass2() d = myClass2() print c = %s % str(c) print d = %s % str(d) print c.clearSet() c.clearSet() print c = %s % str(c) print d = %s % str(d) -- OUTPUT -- python.exe myProg.py a = 9 b = 9 a.clearNum() a = 0 b = 9 c = 9 d = 9 c.clearSet() c = 0 d = 0 -- http://mail.python.org/mailman/listinfo/python-list
Re: Inexplicable behavior in simple example of a set in a class
Instance variables are properly created in the __init__() initializer method, *not* directly in the class body. Your class would be correctly rewritten as: class MyClass2(object): def __init__(self): self.mySet = sets.Set(range(1,10)) def clearSet(self): # ...rest same as before... Thanks Chris. That was certainly very helpful!! So just out of curiosity, why does it work as I had expected when the member contains an integer, but not when the member contains a set? -- http://mail.python.org/mailman/listinfo/python-list
