Thank you for your reply.

Yes i know my coding skills are novice at best, i will look into each and every of your points.

Any idea why the program wont keep running after execvp()? With send() instead it keeps looping as it should.

execvp() used to work just fine and looping some days ago, i don't know why it suddenly doesn't. Maybe after i fiddled around with fork()..?

Skydiver, on 28 January 2013 - 07:56 AM, said:

this indeed was the problem, i was able to program around this in my servercode, now i have a working (but ugly) solution.

i did something like this:

        if(str2[0] >= '+' && str2[0] <= 'DEL')
            spawn2 (str1, arg2);
        else
            spawn1 (str1, arg1);

...where spawn 1 takes 1 less argument than spawn 2, and runs exevpc(...).

so, if str2 happends to contain: "a@@££@££" because its uninitialized, the program will fail, but anyway...

i dont find the "edit post" button here, but i forgot to say thanks for putting me in the right direction!

perhaps a } was missing. this should work:

#include <unistd.h>

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>

#define SOCK_PATH "echo_socket"

int main(void)
{
        int s, s2, t, len;
        struct sockaddr_un local, remote;
        char str[100];
        char* arg_list[222];
    char str1[100], str2[100];

        if ((s = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) {
                perror("socket");
                exit(1);
        }

        local.sun_family = AF_UNIX;
        strcpy(local.sun_path, SOCK_PATH);
        unlink(local.sun_path);
        len = strlen(local.sun_path) + sizeof(local.sun_family);
        if (bind(s, (struct sockaddr *)&local, len) == -1) {
                perror("bind");
                exit(1);
        }

        if (listen(s, 5) == -1) {
                perror("listen");
                exit(1);
        }

        for(;;)/> {
                int active,done, sent, n;
                printf("Waiting for a connection...\n");
                t = sizeof(remote);
                if ((s2 = accept(s, (struct sockaddr *)&remote, &t)) == -1) {
                        perror("accept");
                        exit(1);
                }

                printf("Connected.\n");
        active = 0;
                done = 0;
                sent = 0;
                do {
                        n = recv(s2, str, 100, 0);
                        if (n <= 0) {
                                if (n < 0) perror("recv");
                                done = 1;
                        }





            if(str[0]=='s' && str[1]=='t' && str[2]=='o' && str[3]=='p')
                done = 1;
            if(str[0]=='s' && str[1]=='t' && str[2]=='a' && str[3]=='r'&&
str[4]=='t')
                active = 1;


    str[strcspn ( str, "\n" )] = '\0';
    strcpy(str1,str);

    int i=0,k=0;

    while (str1[i] != ' ')
        i++;

    while (str1[i] != '\0'){
        str2[k] = str1[i+1];
        k++;
        i++;
    }

    i=0;

    while (str1[i] != ' ')
        i++;

    str1[i] = '\0';





    int spawn (char* program, char** arg_list)
    {


      printf("\n%s!!!\n%s!!!",program,arg_list);


        pid_t child_pid;
        child_pid = fork ();
        if (child_pid != 0)
            return child_pid;





        else{
                execvp (program, arg_list);
            }
            fprintf (stderr, "an error occurred in execvp\n");
            abort ();
        }



        char* arg_list[222];
        char kommando[222];
        char * tmp;

        i=0;

        tmp = strtok (kommando," ");
        arg_list[0] = tmp;
        while (tmp != NULL)
        {
            tmp = strtok (NULL, " ");
            arg_list[i+1] = tmp;
            i++;
        }

        char* arg[] = {
        str1,
        str2,
        NULL
        };


        spawn (str1, arg);


                        if (!done && sent == 0 && active == 0)
                                if (send(s2, str, n, 0) < 0) {
                                        perror("send");
                                        sent = 1;
                                }

                        if (!done && sent == 0 && active == 1)
                                if (send(s2, str, n, 0) < 0) {
                                        perror("send");
                                        sent = 1;
                                }
            sent = 0;
                } while (!done);

                close(s2);
        }

        return 0;
}

Skydiver, on 28 January 2013 - 06:56 AM, said:

oh, yes it compiles, the corresponding while is at 136, something went wrong when i pasted it into the forum, intendation perhaps.