Subj : Re: test a computer presence on the network in C
To   : Fabrice Bentejac LM2S
From : Remove the letters in all caps\
Date : Wed Oct 06 2004 07:50 am

Fabrice Bentejac LM2S wrote:

>Hello,
>I'd like to test, inside a C program, whether a computer is present on the
>network (equivalent to a "ping" command.
>What could I use to do that?
>
>Thanks in advance.
>
>F.B.
>  
>
int test(char *computer ){
                                                                                

   int status;
                                                                                

   char buffer[BUFLEN+12];
   char *command = "ping -c 4 ";
                                                                                

   if ( strlen( computer ) + strlen( command ) >= BUFLEN ) {
     fprintf (stderr, "The computer name is 'way too long");
     exit (2);
   };
                                                                                

   strcpy ( buffer, command);   /* copy the command to the buffer, first 
part in building the command string */
   strcat ( buffer, computer ); /* copy the computer name, which 
finishes the command string */
   strcat ( buffer, ">/dev/null" );
   fprintf ( stderr, "The command is %s\n", buffer );
                                                                                

   status = system( buffer );
                                                                                

   return ( status ); 
                                                                          
}
                                                                                

main(){
                                                                                

   printf ( "%s is %s\n",  COMPUTER1, test(COMPUTER1) ? "down" : "up" );
   printf ( "%s is %s\n",  COMPUTER2, test(COMPUTER2) ? "down" : "up" );
                                                                                

}

.