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cbashshellshnetcat

Netcat shell programm

I need, for a course, to program a simple server that answer "Goodbye" when we tell him "Hello". I tried to do that using netcat, but how can I make a script that listen to the client, test his answer, then print the "Goodbye" ? I tried to do :

netcat -l -p 8080 -e bye

with bye.c :

int main(int argc, char ** argl){
    char res[100] ;
    while(1){
        fgets(res, 100, stdin) ;
        if(!strcasecmp(res, "Hello"))
            {printf("Goodbye\n") ; return 0 ; } }

}

but it doesn't seem to work. Can you help me ?

Solution

  • Just replace strcasecmp with strncmp(res, "Hello", 5) and it should work.

    However, you have to avoid blocking of fgets "It stops when either (n-1) characters are read, the newline character is read, or the end-of-file is reached, whichever comes first."