Print Something On Console After Boot

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How do I print something on the text-mode console right after the OS has finished booting?

I’ve a virtual instance and I need to know its IP address after it has finished booting up, to know where to SSH into it. I’ve tried adding “ip
-4 addr > /dev/tty0” to rc.local, but that obviously doesn’t work, because the login prompt overwrites everything I do.

6 thoughts on - Print Something On Console After Boot

  • you can send a mail to your mailbox google Raspberry Pi mailip such as http://elinux.org/RPi_Email_IP_On_Boot_Debian for local network, there is no complicated steps to find the IP
    just get the hardware address of your card and scan the network with nmap.

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  • I might be in left field but…

    in init.d create a script that simply

    echo_ip

    script contents
    #!/bin/bash ip -4 addr |grep inet |tee /var/log/ip # this will only print the ip lines and copy to /var/log/ip ( I prefer tee over echo, for a variety of reasons)

    then create S99echo_ip in rc3.d so that it runs last

    then

  • The easy answer would be: don’t fight the login prompt. “agetty” writes the contents of /etc/issue to the console before the login prompt. If
    /etc/issue contains “\4” then agetty will print the IPv4 address to the console.

    See the man page for agetty, and update /etc/issue.

  • I find that CentOS-6 evidently does not support \; nor many of the /etc/issue flags defined in man 1 agetty:

    /etc/issue CentOS release 6.6 (Final)
    Kernel \r on an \m

    Test: b:\b d:\d s:\s l:\l m:\m n:\n o:\o O:\O r:\r t:\t u:\u 0:\0 4:\4 6:\6

    login:

    CentOS release 6.6 (Final)
    Kernel 2.6.32-504.1.3.el6.CentOS.plus.x86_64 on an x86_64

    Test: b: d:09:19 on Thursday, 11 December 2014 s:Linux l:7 m:x86_64
    n:vhost04.hamilton.harte-lyne.ca o: O: r:2.6.32-504.1.3.el6.CentOS.plus.x86_64
    t:09:19 on Thursday, 11 December 2014 u: 0: 4: 6:

    For ease in analysis (note that flags \0, \4, and \6 are not defined in agetty):

    b:
    d:09:19 on Thursday, 11 December 2014
    s:Linux l:7
    m:x86_64
    n:vhost04.hamilton.harte-lyne.ca o:
    O:
    r:2.6.32-504.1.3.el6.CentOS.plus.x86_64
    t:09:19 on Thursday, 11 December 2014
    u:
    0:
    4:
    6:

    Is there some configuration issue of which I am unaware? Where is the flag \4
    usage defined?

  • Looks like you are seeing the codes defined for mingetty rather than agetty. This is what you would expect for a virtual console on CentOS 6
    which uses the former.

    K
    ​al​