Este es el /usr/bin/yum

[quote]
#!/usr/bin/python
import sys
try:
import yum
except ImportError:
print >> sys.stderr, """\
There was a problem importing one of the Python modules
required to run yum. The error leading to this problem was:

%s

Please install a package which provides this module, or
verify that the module is installed correctly.

It's possible that the above module doesn't match the
current version of Python, which is:
%s

If you cannot solve this problem yourself, please go to
the yum faq at:
http://wiki.linux.duke.edu/YumFaq

""" % (sys.exc_value, sys.version)
sys.exit(1)

sys.path.insert(0, '/usr/share/yum-cli')
try:
import yummain
yummain.main(sys.argv[1:])
except KeyboardInterrupt, e:
print >> sys.stderr, "\n\nExiting on user cancel."
sys.exit(1)
[/quote]

Aquí va /usr/share/yum-cli/yummain.py

[quote]
import sys
import locale
import time # test purposes only

from yum import Errors
from yum import plugins
import cli

from i18n import _

YUM_PID_FILE = '/var/run/yum.pid'

def main(args):
"""This does all the real work"""

def exUserCancel():
base.errorlog(0, '\n\nExiting on user cancel')
unlock()
sys.exit(1)

def exIOError(e):
if e.errno == 32:
base.errorlog(0, '\n\nExiting on Broken Pipe')
unlock()
sys.exit(1)

def exPluginExit(e):
'''Called when a plugin raises PluginYumExit.
Log the plugin's exit message if one was supplied.
'''
exitmsg = str(e)
if exitmsg:
base.errorlog(2, '\n\n%s' % exitmsg)
unlock()
sys.exit(1)

def exFatal(e):
base.errorlog(0, '\n\n%s' % str(e))
unlock()
sys.exit(1)

def unlock():
try:
base.closeRpmDB()
base.doUnlock(YUM_PID_FILE)
except Errors.LockError, e:
sys.exit(200)

try:
locale.setlocale(locale.LC_ALL, '')
except locale.Error, e:
# default to C locale if we get a failure.
print >> sys.stderr, 'Failed to set locale, defaulting to C'
locale.setlocale(locale.LC_ALL, 'C')

# our core object for the cli
base = cli.YumBaseCli()

# do our cli parsing and config file setup
# also sanity check the things being passed on the cli
try:
base.getOptionsConfig(args)
except plugins.PluginYumExit, e:
exPluginExit(e)
except Errors.YumBaseError, e:
exFatal(e)
try:
base.doLock(YUM_PID_FILE)
except Errors.LockError, e:
base.errorlog(0,'%s' % e.msg)
sys.exit(200)

# build up an idea of what we're supposed to do
if base.basecmd == 'shell':
do = base.doShell
else:
do = base.doCommands
try:
result, resultmsgs = do()
except plugins.PluginYumExit, e:
exPluginExit(e)
except Errors.YumBaseError, e:
result = 1
resultmsgs = [str(e)]
except KeyboardInterrupt:
exUserCancel()
except IOError, e:
exIOError(e)

# Act on the command/shell result
if result == 0:
# Normal exit
for msg in resultmsgs:
base.log(2, '%s' % msg)
unlock()
sys.exit(0)
elif result == 1:
# Fatal error
for msg in resultmsgs:
base.errorlog(0, 'Error: %s' % msg)
unlock()
sys.exit(1)
elif result == 2:
# Continue on
pass
elif result == 100:
unlock()
sys.exit(100)
else:
base.errorlog(0, 'Unknown Error(s): Exit Code: %d:' % result)
for msg in resultmsgs:
base.errorlog(0, msg)
unlock()
sys.exit(3)

# Depsolve stage
base.log(2, 'Resolving Dependencies')
base.log(3, time.time())
try:
(result, resultmsgs) = base.buildTransaction()
except plugins.PluginYumExit, e:
exPluginExit(e)
except Errors.YumBaseError, e:
result = 1
resultmsgs = [str(e)]
except KeyboardInterrupt:
exUserCancel()
except IOError, e:
exIOError(e)

# Act on the depsolve result
if result == 0:
# Normal exit
unlock()
sys.exit(0)
elif result == 1:
# Fatal error
for msg in resultmsgs:
base.errorlog(0, 'Error: %s' % msg)
unlock()
sys.exit(1)
elif result == 2:
# Continue on
pass
else:
base.errorlog(0, 'Unknown Error(s): Exit Code: %d:' % result)
for msg in resultmsgs:
base.errorlog(0, msg)
unlock()
sys.exit(3)

base.log(2, '\nDependencies Resolved')
base.log(3, time.time())

# Run the transaction
try:
base.doTransaction()
except plugins.PluginYumExit, e:
exPluginExit(e)
except Errors.YumBaseError, e:
exFatal(e)
except KeyboardInterrupt:
exUserCancel()
except IOError, e:
exIOError(e)

base.log(2, 'Complete!')
unlock()
sys.exit(0)

if __name__ == "__main__":
#import hotshot
#p = hotshot.Profile(os.path.expanduser("~/yum.prof"))
#p.run('main(sys.argv[1:])')
#p.close()
try:
main(sys.argv[1:])
except KeyboardInterrupt, e:
print >> sys.stderr, "\n\nExiting on user cancel."
sys.exit(1)

[/quote]

Saludos

Juan Yépez

Juan Yépez
093681879