Remove the newline before `/etc/issue` in tty

Question

I want to remove the default newline inserted before the content of /etc/issue on login prompt in tty. I'm using agetty and systemd.

I tried to add the --nonewline option to my [email protected] :

ExecStart=/sbin/agetty --nonewline --noclear %I $TERM

That result in :

# systemctl status -l [email protected]
● [email protected] - Getty on tty5
  Loaded: loaded (/usr/lib/systemd/system/[email protected]; disabled)
  Active: failed (Result: start-limit) since sam. 2014-05-17 23:50:13 CEST; 56s ago
    Docs: man:agetty(8)
          man:systemd-getty-generator(8)
          http://0pointer.de/blog/projects/serial-console.html
 Process: 14538 ExecStart=/sbin/agetty --nonewline --noclear %I $TERM (code=exited, status=1/FAILURE)
Main PID: 14538 (code=exited, status=1/FAILURE)

systemd[1]: [email protected] has no holdoff time, scheduling restart.
systemd[1]: Stopping Getty on tty5...
systemd[1]: Starting Getty on tty5...
systemd[1]: [email protected] start request repeated too quickly, refusing to start.
systemd[1]: Failed to start Getty on tty5.
systemd[1]: Unit [email protected] entered failed state.

And I get :

# journalctl --no-pager -b -u [email protected]
-- Logs begin at sam. 2013-10-12 00:20:12 CEST, end at sam. 2014-05-17 23:52:49 CEST. --
systemd[1]: Starting Getty on tty5...
systemd[1]: Started Getty on tty5.
agetty[14497]: Usage:
agetty[14497]: agetty [options] <line> [<baud_rate>,...] [<termtype>]
agetty[14497]: agetty [options] <baud_rate>,... <line> [<termtype>]
agetty[14497]: Options:
agetty[14497]: -8, --8bits                assume 8-bit tty
agetty[14497]: -a, --autologin <user>     login the specified user automatically
agetty[14497]: -c, --noreset              do not reset control mode
agetty[14497]: -E, --remote               use -r <hostname> for login(1)
agetty[14497]: -f, --issue-file <file>    display issue file
agetty[14497]: -h, --flow-control         enable hardware flow control
agetty[14497]: -H, --host <hostname>      specify login host
agetty[14497]: -i, --noissue              do not display issue file
agetty[14497]: -I, --init-string <string> set init string
agetty[14497]: -l, --login-program <file> specify login program
agetty[14497]: -L, --local-line[=<mode>]  control the local line flag
agetty[14497]: -m, --extract-baud         extract baud rate during connect
agetty[14497]: -n, --skip-login           do not prompt for login
agetty[14497]: -o, --login-options <opts> options that are passed to login
agetty[14497]: -p, --login-pause          wait for any key before the login
agetty[14497]: -r, --chroot <dir>         change root to the directory
agetty[14497]: -R, --hangup               do virtually hangup on the tty
agetty[14497]: -s, --keep-baud            try to keep baud rate after break
agetty[14497]: -t, --timeout <number>     login process timeout
agetty[14497]: -U, --detect-case          detect uppercase terminal
agetty[14497]: -w, --wait-cr              wait carriage-return
agetty[14497]: --noclear              do not clear the screen before prompt
agetty[14497]: --nohints              do not print hints
agetty[14497]: --nonewline            do not print a newline before issue
agetty[14497]: --nohostname           no hostname at all will be shown
agetty[14497]: --long-hostname        show full qualified hostname
agetty[14497]: --erase-chars <string> additional backspace chars
agetty[14497]: --kill-chars <string>  additional kill chars
agetty[14497]: --help                 display this help and exit
agetty[14497]: --version              output version information and exit
agetty[14497]: For more details see agetty(8).
systemd[1]: [email protected] has no holdoff time, scheduling restart.
systemd[1]: Stopping Getty on tty5...

Why agetty don't want to recognize the option ? Is there another way to do that ?

Answer 1

You have hit a bug! There's a F_NONL directive that never gets called in the agetty binary as can be seen in the sources:

...
#define F_NONL      (1<<17) /* No newline before issue */
...
/* Parse command-line arguments. */
static void parse_args(int argc, char **argv, struct options *op)
{
    int c;

    enum {
            VERSION_OPTION = CHAR_MAX + 1,
            NOHINTS_OPTION,
            NOHOSTNAME_OPTION,
            LONGHOSTNAME_OPTION,
            HELP_OPTION,
            ERASE_CHARS_OPTION,
            KILL_CHARS_OPTION,
    };
    const struct option longopts[] = {
            {  "8bits",      no_argument,    0,  '8'  },
            {  "autologin",      required_argument,  0,  'a'  },
            ...
            {  "skip-login",     no_argument,    0,  'n'  },
            {  "nonewline",      no_argument,    0,  'N'  },
    while ((c = getopt_long(argc, argv,
               "8a:cC:d:Ef:hH:iI:Jl:L::mnNo:pP:r:Rst:Uw", longopts,
                NULL)) != -1) {
        switch (c) {
        case '8':
            op->flags |= F_EIGHTBITS;
            break;
        case 'a':
            op->autolog = optarg;
            break;
        case 'c':
            op->flags |= F_KEEPCFLAGS;
            break;
        case 'C':
            op->chdir = optarg;
            break;
        case 'd':
            op->delay = atoi(optarg);
            break;
        case 'E':
            op->flags |= F_REMOTE;
            break;
        case 'f':
            op->flags |= F_CUSTISSUE;
            op->issue = optarg;
            break;
        case 'h':
            op->flags |= F_RTSCTS;
            break;
        case 'H':
            fakehost = optarg;
            break;
        case 'i':
            op->flags &= ~F_ISSUE;
            break;
        case 'I':
            init_special_char(optarg, op);
            op->flags |= F_INITSTRING;
            break;
        case 'J':
            op->flags |= F_NOCLEAR;
            break;
        case 'l':
            op->login = optarg;
            break;
        case 'L':
            /* -L and -L=always have the same meaning */
            op->clocal = CLOCAL_MODE_ALWAYS;
            if (optarg) {
                if (strcmp(optarg, "=always") == 0)
                    op->clocal = CLOCAL_MODE_ALWAYS;
                else if (strcmp(optarg, "=never") == 0)
                    op->clocal = CLOCAL_MODE_NEVER;
                else if (strcmp(optarg, "=auto") == 0)
                    op->clocal = CLOCAL_MODE_AUTO;
                else
                    log_err(_("invalid argument of --local-line"));
            }
            break;
        case 'm':
            op->flags |= F_PARSE;
            break;
        case 'n':
            op->flags |= F_NOPROMPT;
            break;
        case 'o':
            op->logopt = optarg;
            break;
        case 'p':
            op->flags |= F_LOGINPAUSE;
            break;
        case 'P':
            op->nice = atoi(optarg);
            break;
        case 'r':
            op->chroot = optarg;
            break;
        case 'R':
            op->flags |= F_HANGUP;
            break;
        case 's':
            op->flags |= F_KEEPSPEED;
            break;
        case 't':
            if ((op->timeout = atoi(optarg)) <= 0)
                log_err(_("bad timeout value: %s"), optarg);
            break;
        case 'U':
            op->flags |= F_LCUC;
            break;
        case 'w':
            op->flags |= F_WAITCRLF;
            break;
        case NOHINTS_OPTION:
            op->flags |= F_NOHINTS;
            break;
        case NOHOSTNAME_OPTION:
            op->flags |= F_NOHOSTNAME;
            break;
        case LONGHOSTNAME_OPTION:
            op->flags |= F_LONGHNAME;
            break;
        case ERASE_CHARS_OPTION:
            op->erasechars = optarg;
            break;
        case KILL_CHARS_OPTION:
            op->killchars = optarg;
            break;
        case VERSION_OPTION:
            printf(_("%s from %s\n"), program_invocation_short_name,
                   PACKAGE_STRING);
            exit(EXIT_SUCCESS);
        case HELP_OPTION:
            usage(stdout);
        default:
            usage(stderr);
        }
    }

In the while loop there should be a block like below, which is missing.

case 'N':
op->flags |= F_NONL;
break;

I think is a trivial patch to add. You can check the full source code in GitHub or kernel.org.