Phoe6 wrote:
> Hi all,
> Part of my script is to check for pre-requisite rpms to be
> installed.
> If its installed, I just display the rpm version as in rpm database,
> otherwise I output a message saying:
> ' rpm is not installed' and collect the rpm name in a list
> (notInstalled).
> At the end if the len(notInstalled) is greater than 0 then I display
> them all asking it to be installed and exit the program.
> My Script is below:
> -------
> def checkForRpm(rpmname):
> ''' Check for the presence of the RPM. '''
> cin,cout,cerr = os.popen3('rpm -q ' + rpmname)
> output = cout.read()
> global notInstalled
> if len(output) <= 0:
> print rpmname + ' not installed.'
> notInstalled.append(rpmname)
> else:
> print output
>
>
>
> def preReqCheckRpms():
> ''' Check for the required RPMS '''
> listOfRpms = ['firefox','senthil',]
>
>
> for eachRpm in listOfRpms:
> checkForRpm(eachRpm)
> global notInstalled
> if len(notInstalled) > 0:
> print 'The following RPMS are not installed:'
> for eachRpm in notInstalled:
> print eachRpm
> print 'Please install them for the installation to
> continue.'
> sys.exit(-1)
>
> * This is NOT Working.
> * notInstalled.append(rpmname) is not taking effect in
> checkForRpm(rpmname)
> * I dont know how to communicate the notInstalled list to
> preReqCheckRpms.
>
> --
> Senthil
I think return values should be used for communication between
functions. Maybe something like this could work for you (not tested).
def checkForRpm(rpmname):
# <cut start of function>
# Strings with 0 lenght are False
if output:
print output
else:
print rpmname + ' is not installed'
return output
def checkPreReqs():
missingRpms = []
for requiredRpm in listOfRpms:
if not checkForRpm(requiredRpm):
missingRpms.append(requiredRpm)
# you could also do this by a list comprehension
missingRpms = [reqRpm for reqRpm in listOfRpms if not
checkForRpm(reqRpm)]
# or you could use the builtin function filter() - see
filter.__doc__ for that
# now, list of lenght 0 is False.
if missingRpms:
# print error messages, exit.
--
Juho Schultz
--
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