wip, converting from sh to python (urgh)

diff --git a/virt-chroot/adt-virt-chroot b/virt-chroot/adt-virt-chroot
index efb12c562ab707a1831bea225d80f57aeb87a35a..f969b1d051aba3f154be098cf3e0a9b3d1abf9c6 100755 (executable)
--- a/virt-chroot/adt-virt-chroot
+++ b/virt-chroot/adt-virt-chroot
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/usr/bin/python
 # usage:
 #      adt-virt-chroot =[CHROOTNAME]
 #              uses dchroot (but problems with spaces)
@@ -7,63 +7,127 @@
 #              uses GAINROOT chroot
 #              GAINROOT will be split up if it has spaces
 
-set -e
-
-fail () { echo >&2 "$0: $@"; exit 16; }
-
-gainroot=''
-
-while [ $# -gt 0 ]; do
-       case "$1" in
-       --|-)   break=break; break; shift               ;;
-       -r*)    gainroot="${1#-r}"                      ;;
-       -*)     fail "bad usage - unknown option $1"    ;;
-       *)      break=break; break                      ;;
-       esac
-       $break
-       shift
-done
-
-[ $# -eq 1 ] || fail "bad usage - need =DCHROOTNAME or /CHROOT/PATH"
-
-case "$1" in
-/*)    down="$gainroot chroot $1 --"                           ;;
-=?*)   down="$gainroot dchroot -d\"${1#=}\" -q"                ;;
-=)     down="$gainroot dchroot -q"                             ;;
-*)     fail "bad usage - unknown chroot specification $1"      ;;
-esac
-
-echo ok
-
-close_down () {
-       [ "x$downtmp" = x ] || $down rm -rf -- "$downtmp"
-       downtmp=''
-}
-
-trap 'close_down; exit 12;' 0
-
-while read command; do
-       case $command in
-       capabilities)
-               echo 'ok '
-               ;;
-       quit)
-               trap '' 0
-               close_down
-               exit 0
-               ;;
-       open)
-               [ "x$downtmp" = x ] || fail '"open" when already open'
-               downtmp="$($down mktemp -t -d)"
-               echo ok
-               ;;
-       'stop *')
-               
-               
-       *)
-               fail "unrecognised command $command"
-               ;;
-       esac
-done
-
-fail 'unexpected EOF on control channel'
+import sys
+import string
+import urllib
+import signal
+from optparse import OptionParser
+
+debuglevel = None
+
+class Quit(ecode):
+       def __init__(q,ec): q.ec = ec;
+
+def bomb(m):
+       print >> sys.stderr "adt-virtual-chroot: failure:", m
+       raise Quit(16)
+
+def debug(m):
+       if not debuglevel: return
+       print >> sys.stderr, "adt-virt-chroot: debug:", m
+
+def parse_args():
+       global down, debuglevel
+
+       usage = "%prog [options] =<dchroot>|/path/to/chroot"
+       parser = OptionParser(usage=usage)
+       pa = parser.add_option
+       pe = parser.error
+
+       pa('-r', '--gain-root', type='string', dest='gain_root');
+       pa('-d', '--debug', action='store_true', dest='debug');
+
+       (opts,args) = parser.parse_args()
+       if len(args) != 1: pe("need exactly one arg, chroot specification")
+
+       debuglevel = opts.debug
+
+       chroot_arg = args[0]
+       if not chroot_arg: pe("chroot specification may not be empty")
+       if chroot_arg == '=': down = ['dchroot','-q']
+       elif chroot_arg[0] == '=': down = ['dchroot','-q','-d'+chroot_arg[1:]]
+       elif chroot_arg[0] == '/': down = ['chroot',chroot_arg,'--']
+       else: pe("chroot spec must be =[DCHROOT] or /PATH/TO/CHROOT")
+
+       if opts.gain_root != None: down = opts.gain_root.split() + down
+
+       debug("down = %s" % string.join(down))  
+
+def ok(): print 'ok'
+
+def cmdnoargs(c, cu):
+       if len(c) == 1: return
+       bomb("too many arguments to command `%s'": cu[0])
+
+def cmd_capabilities(c, cu):
+       cmdnoargs(c, cu)
+
+def cmd_quit(c, cu):
+       cmdnoargs(c, cu)
+       raise Quit(0)
+
+def cmd_open(c, cu):
+       cmdnoargs(c, cu)
+       if downtmp: bomb("`open' when already open")
+       downtmp = sys.exec
+
+def command():
+       cu = sys.stdin.readline()
+       cu = c.rstrip().split()
+       c = map(urllib.unquote, cu)
+       if not c: bomb('empty commands are not permitted')
+       try: f = globals()['cmd_'+c[0]]
+       except ValueError: bomb("unknown command `%s'" % cu[0])
+       r = f(c, cu)
+       if not r: r = ()
+       r.insert(0, 'ok')
+       ru = map(urllib.quote, r)
+       print string.join(ru)
+
+def cleanup():
+       global downtmp, cleaning
+       cleaning = True
+       if downtmp:
+               pass
+       cleaning = False
+
+def prepare():
+       global downtmp, cleaning
+       downtmp = None
+       signal_list = [ signal.SIGHUP, signal.SIGTERM,
+                       signal.SIGINT, signal.SIGPIPE ]
+       def sethandlers(f):
+               for signum in signal_list: signal(signum, f)
+       def handler(args):
+               sethandlers(signal.SIG_DFL)
+               cleanup()
+       sethandlers(handler)
+
+parse_args()
+ok()
+prepare()
+
+try:
+       while True: command()
+except Quit, q:
+       cleanup()
+       exit(q.ec)
+except:
+       cleanup()
+       raise
+
+#      open)
+#              [ "x$downtmp" = x ] || fail '"open" when already open'
+#              downtmp="$($down mktemp -t -d)"
+#              echo ok
+#              ;;
+#      'stop *')
+#              
+#              
+#      *)
+#              fail "unrecognised command $command"
+#              ;;
+#      esac
+# done
+# 
+# fail 'unexpected EOF on control channel'