Comment 1 for bug 1273159

$ udhcpc -?
udhcpc: invalid option -- ?
BusyBox v1.20.1 (2013-02-08 03:29:16 UTC) multi-call binary.

Usage: udhcpc [-fbnqoCRB] [-i IFACE] [-r IP] [-s PROG] [-p PIDFILE]
 [-V VENDOR] [-x OPT:VAL]... [-O OPT]...

 -i,--interface IFACE Interface to use (default eth0)
 -p,--pidfile FILE Create pidfile
 -s,--script PROG Run PROG at DHCP events (default /usr/share/udhcpc/default.script)
 -B,--broadcast Request broadcast replies
 -t,--retries N Send up to N discover packets
 -T,--timeout N Pause between packets (default 3 seconds)
 -A,--tryagain N Wait N seconds after failure (default 20)
 -f,--foreground Run in foreground
 -b,--background Background if lease is not obtained
 -n,--now Exit if lease is not obtained
 -q,--quit Exit after obtaining lease
 -R,--release Release IP on exit
 -S,--syslog Log to syslog too
 -a,--arping Use arping to validate offered address
 -O,--request-option OPT Request option OPT from server (cumulative)
 -o,--no-default-options Don't request any options (unless -O is given)
 -r,--request IP Request this IP address
 -x OPT:VAL Include option OPT in sent packets (cumulative)
    Examples of string, numeric, and hex byte opts:
    -x hostname:bbox - option 12
    -x lease:3600 - option 51 (lease time)
    -x 0x3d:0100BEEFC0FFEE - option 61 (client id)
 -F,--fqdn NAME Ask server to update DNS mapping for NAME
 -V,--vendorclass VENDOR Vendor identifier (default 'udhcp VERSION')
 -C,--clientid-none Don't send MAC as client identifier
Signals:
 USR1 Renew lease
 USR2 Release lease