busybox/loginutils
Denys Vlasenko 237bedd499 getopt32: add new syntax of 'o:+' and 'o:*' for -o NUM and -o LIST
In many cases, this aqllows to drop use of opt_complementary.
Approximately -400 bytes:

function                                             old     new   delta
getopt32                                            1423    1502     +79
opt_string                                            17      18      +1
OPT_STR                                               24      25      +1
uniq_main                                            416     406     -10
timeout_main                                         279     269     -10
sulogin_main                                         270     260     -10
readprofile_main                                    1825    1815     -10
ps_main                                              543     533     -10
pidof_main                                           245     235     -10
pgrep_main                                           611     601     -10
od_main                                             2600    2590     -10
mkfs_minix_main                                     2684    2674     -10
mkfs_ext2_main                                      2603    2593     -10
microcom_main                                        712     702     -10
makemime_main                                        315     305     -10
ionice_main                                          282     272     -10
inetd_main                                          2074    2064     -10
ifplugd_main                                        1144    1134     -10
halt_main                                            353     343     -10
getopt_main                                          636     626     -10
fdisk_main                                          2854    2844     -10
env_main                                             206     196     -10
dmesg_main                                           319     309     -10
conspy_main                                         1214    1204     -10
awk_main                                             981     971     -10
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 3/22 up/down: 81/-220)         Total: -139 bytes
   text	   data	    bss	    dec	    hex	filename
 919373	    906	  14060	 934339	  e41c3	busybox_old
 918969	    906	  14060	 933935	  e402f	busybox_unstripped

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2016-07-06 21:58:02 +02:00
..
add-remove-shell.c loginutils/*: convert to new-style "one file" applets 2015-10-19 01:20:36 +02:00
addgroup.c loginutils/*: convert to new-style "one file" applets 2015-10-19 01:20:36 +02:00
adduser.c loginutils/*: convert to new-style "one file" applets 2015-10-19 01:20:36 +02:00
chpasswd.c Replace a few more bb_info_msg's by bb_error_msg or printf 2016-03-30 16:20:28 +02:00
Config.src loginutils/*: convert to new-style "one file" applets 2015-10-19 01:20:36 +02:00
cryptpw.c getopt32: add new syntax of 'o:+' and 'o:*' for -o NUM and -o LIST 2016-07-06 21:58:02 +02:00
deluser.c loginutils/*: convert to new-style "one file" applets 2015-10-19 01:20:36 +02:00
getty.c getopt32: add new syntax of 'o:+' and 'o:*' for -o NUM and -o LIST 2016-07-06 21:58:02 +02:00
Kbuild.src loginutils/*: convert to new-style "one file" applets 2015-10-19 01:20:36 +02:00
login.c *: add most of the required setup_common_bufsiz() calls 2016-04-21 18:18:48 +02:00
passwd.c Replace a few more bb_info_msg's by bb_error_msg or printf 2016-03-30 16:20:28 +02:00
README getty: fix a minor problem of Ctrl-D not printing '\n' 2011-10-23 23:58:59 +02:00
su.c loginutils/*: convert to new-style "one file" applets 2015-10-19 01:20:36 +02:00
sulogin.c getopt32: add new syntax of 'o:+' and 'o:*' for -o NUM and -o LIST 2016-07-06 21:58:02 +02:00
vlock.c loginutils/*: convert to new-style "one file" applets 2015-10-19 01:20:36 +02:00

	Getty

??? Should getty open tty with or without O_NONBLOCK?
For serial lines, it means "should getty wait for Carrier Detect pin?"
I checked other getties:

- agetty always uses O_NONBLOCK
- mgetty uses O_NONBLOCK unless run with -b, or as "getty"

??? If we decided to use O_NONBLOCK (perhaps optionally with -b),
when getty should send -I INITSTR data to tty? After open succeeds?
What if we also want to initialize *modem* with some AT commands?

??? Should we check/create /var/lock/LCK..ttyPFX lockfiles?

??? mgetty opens tty but does NOT lock it, then waits for input via
select/poll, and when input is available, it checks lock file.
If it exists, mgetty exits (it assumes someone else uses the line).
If no, it creates the file (lock the tty). Sounds like a good algorithm
to use if we are called with -w...

Getty should establish a new session and process group, and ensure
that tty is a ctty.

??? Should getty ensure that other processes which might have opened
fds to this tty be dusconnected? agetty has a -R option which makes
agetty call vhangup() after tty is opened. (Then agetty opens it again,
since it probably vhangup'ed its own fd too).

Getty should leave the tty in approximately the same state as "stty sane"
before it execs login program. Minor things we do conditionally are:
	c_iflag |= ICRNL; // if '\r' was used to end username

??? mgetty uses per-tty file to ignore connects, /etc/nologin.ttyxx -
is it useful?

It should be possible to run "getty 0 -" from a shell prompt.
[This currently doesn't work from interactive shell since setsid()
fails in process group leader. The workaround is to run it as a child
of something. sh -c 'getty - 0; true' usually works. Should we fix this?]
It should leave tty in a sane state when it exits (Ctrl-D, -t SEC timeout):
echo should be on, speed, control chars properly set, etc.
(However, it can't restore ctty. The symptom is that "</dev/tty"
fails in the parent shell after getty exits: /dev/tty can't be opened).

Getty should write LOGIN_PROCESS utmp record before it starts waiting
for username to be entered.

	Login

Login should not try to set up tty parameters - apart from switching echo
off while entering password, and switching it back on after.

Login should not leave "echo off" state when it times out reading password
or otherwise terminates (Ctrl-C, Ctrl-D etc).

??? Should login establish a new session and/or process group, and ensure
that tty is a ctty? Without this, running login directly (not via getty)
from e.g. initscript will usually result with a login session without
ctty and without session/pgrp properly created...

It should be possible to run "login [USER]" from a shell prompt,
and it should work (not block/die/error out).
Similarly to getty, it should leave tty in the sane state when it exits.

??? Should login write LOGIN_PROCESS utmp record before it starts waiting
for username/password to be entered?

Login should write USER_PROCESS utmp record just before it is about
to exec user's shell.