generating graphs using cairo was relatively very easy, i ran this on a debian box. First you need to install “bazaar”
root@server:/usr/src/python# apt-get install bzr
you might need python-cairo and other dependencies..
root@server:/usr/src/python# apt-get install python-cairo python-cairo-dev python-cairo-dbg python-pycha python-gasp python-docky
An example on how to use python’s subprocess.Popen function:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 | #!/usr/bin/env python import subprocess import os #import pdb; pdb.set_trace() def find(): y = raw_input("Enter a text you want to search on the system!") s = y.rstrip("\n") print "string", s # command = "find /bin -name " + str(y) # arg = ['/usr/bin/find', '/bin', '-name', s '-print'] # print "command", command find = subprocess.Popen([r"/usr/bin/find", "/", "-name", y, "-print"], stdout=subprocess.PIPE) #find_stdout = find.communicate()[0] #print (find_stdout) for line in find.stdout.readlines(): print "line", line l = line.rstrip("\n") list = subprocess.Popen([r"ls", "-l", l], stdout=subprocess.PIPE) list_stdout = list.communicate()[0] print list_stdout file = subprocess.Popen([r"file", l], stdout=subprocess.PIPE) file_stdout = file.communicate()[0] print file_stdout def main(): find() main() |
You can also catch stdout and stderr using subprocess below is a simple example…
1 2 3 4 5 6 7 | >>> import subprocess >>> proc = subprocess.Popen([r"ls /etc /etc/nonexistant"], shell=True, stderr=subprocess.PIPE, stdout=subprocess.PIPE) >>> stdout,stderr = proc.communicate() >>> print stdout blah blah ..output from ls stripped... >>> print stderr ls: cannot access /etc/nonexistant: No such file or directory |
more examples:
1 2 3 4 5 | >>> import subprocess >>> proc = subprocess.Popen([r"uname -a"], shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE) >>> stdout,stderr = proc.communicate() >>> print stdout Linux cce-syslog-001.ceremonies.local 2.6.32-71.29.1.el6.x86_64 #1 SMP Mon Jun 27 19:49:27 BST 2011 x86_64 x86_64 x86_64 GNU/Linux |
you can feed the standard output of one command into the standard input of another command, this example shows you how:
1 2 3 4 5 6 7 8 9 10 11 | >>> import subprocess >>> proc = subprocess.Popen("cat /etc/passwd", shell=True, stdout=subprocess.PIPE,stdin=subprocess.PIPE) >>> filter = subprocess.Popen("grep root ", shell=True, stdin=proc.stdout,stdout=subprocess.PIPE) >>> for i in filter.stdout: ... print i ... root:x:0:0:root:/root:/bin/bash operator:x:11:0:operator:/root:/sbin/nologin >>> |
This is a simple python system monitoring script using subprocess.call and os.popen function, since they use the internal unix commands to poll the server, if you want a portable script which would work across different OS then psutils is more suitable http://code.google.com/p/psutil/
But the advantage of this script is that it can calculate memory and cpu per process for apache,bind etc…
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 | #!/usr/bin/env python from subprocess import Popen, PIPE, STDOUT import subprocess import os import popen2 def memory(): print "gathering memory info..." subprocess.call("free", shell=True) def cpu(): print "gathering system uptime info... " subprocess.call("uptime", shell=True) def pci(): print "gathering pci devices.." subprocess.call("lspci", shell=True) def apache(): print "calculating apache mem use.." sum = 0.0 command = os.popen("ps aux | grep apache | awk '{print $4}'") for i in command.readlines(): l = i.rstrip("\n") d = float(l) sum = d + sum print sum def exim(): print "calculating exim mem use..." esum = 0.0 ecommand = os.popen("ps aux | grep -v grep | grep exim | awk '{print $4}'") for e in ecommand.readlines(): f = e.rstrip("\n") g = float(f) esum = g + esum print esum def spam(): print "calculating spamd mem use.." ssum = 0.0 spamd = os.popen("ps aux | grep spamd | awk '{print $4}'") for s in spamd.readlines(): t = s.rstrip("\n") u = float(t) ssum = u + ssum print ssum def log(): print "logged in users..." subprocess.call("last| grep 'still'", shell=True) def main(): memory() cpu() # pci() apache() spam() exim() log() main() |
