"""

Terminal creation and cleanup.

Utility functions to run a term (connected via screen(1)) on each host.

Requires GNU screen(1) and xterm(1).

Optionally uses gnome-terminal.

"""

import re

from subprocess import Popen

from mininet.log import error

from mininet.util import quietRun

def quoteArg( arg ):

"Quote an argument if it contains spaces."

return repr( arg ) if ' ' in arg else arg

def makeTerm( node, title='Node', term='xterm' ):

"""Run screen on a node, and hook up a terminal.

node: Node object

title: base title

term: 'xterm' or 'gterm'

returns: process created"""

title += ': ' + node.name

if not node.inNamespace:

title += ' (root)'

cmds = {

'xterm': [ 'xterm', '-title', title, '-e' ],

'gterm': [ 'gnome-terminal', '--title', title, '-e' ]

}

if term not in cmds:

error( 'invalid terminal type: %s' % term )

return

if not node.execed:

node.cmd( 'screen -dmS ' + 'mininet.' + node.name)

args = [ 'screen', '-D', '-RR', '-S', 'mininet.' + node.name ]

else:

args = [ 'sh', '-c', 'exec tail -f /tmp/' + node.name + '*.log' ]

if term == 'gterm':

# Compress these for gnome-terminal, which expects one token

# to follow the -e option

args = [ ' '.join( [ quoteArg( arg ) for arg in args ] ) ]

return Popen( cmds[ term ] + args )

def cleanUpScreens():

"Remove moldy old screen sessions."

r = r'(\d+\.mininet\.[hsc]\d+)'

output = quietRun( 'screen -ls' ).split( '\n' )

for line in output:

m = re.search( r, line )

if m:

quietRun( 'screen -S ' + m.group( 1 ) + ' -X quit' )

def makeTerms( nodes, title='Node', term='xterm' ):

"""Create terminals.

nodes: list of Node objects

title: base title for each

returns: list of created terminal processes"""

return [ makeTerm( node, title, term ) for node in nodes ]