How can I fix this error & ldquo; was not declared within this scope.

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System is: Linux/CentOS 6.4

I keep getting an error for functions not declared in scope. Is it not legal to call a function within another function? I read an article on function, thought it was because I needed to declare the functions void when I call them, but I received new errors. Not sure if I need to declare them global or something.

client.cpp:32: error: 'takef' was not declared in this scope

client.cpp:33: error: 'putf' was not declared in this scope

client.cpp: In function 'void takef(int&)':

client.cpp:44: error: 'testa' was not declared in this scope

client.cpp: In function 'void putf(int&)':

client.cpp:70: error: 'test' was not declared in this scope

example of type of code I'm trying to implement

sem_t mutex;
sem_t S;
char buffer[1024];
void error(const char *msg)
{
    perror(msg);
    exit(0);
}
/*void signal_callback_handler()
    {
        close(sockfd);

    }*/

    void father(int &sockfd)
    {
        while(1)
        {
            srand(time(NULL));
            int ms= rand() % 2000 + 5000
            send(sockfd, DATA, strlen(DATA), 0);
            usleep(1000*ms);
            takef(sockfd);
            putf(sockfd);
        }

    }

    void takef(int &sockfd)
    {

    *
    *
    *  *Other code*
    *
    *
    *
        testa(sockfd);

    *  *Other code*
    *
    *
    *
    }

    void testa(int &sockfd)
    {
    *
    *
    *
    *  *Other code*
    *
    *
    *

    }

    void putf(&sockfd)
    {
    *
    *
    *
    *  *Other code*
    *
    *
    *
    test();
    test();
    sem_post(&mutex);

   }

int main(int argc, char *argv[])
{
    *
    *
    *
    *  *Other code*
    *
    *
    *
    father(sockfd);

    return 0;

}


Simple fix. Move the function definitions above the void father() function

In code

sem_t mutex;
sem_t S;
char buffer[1024];
void error(const char *msg)
{
 perror(msg);
 exit(0);
}

/*void signal_callback_handler()
{
    close(sockfd);

}*/

   void takef(int &sockfd)
{

*
*
*  *Other code*
*
*
*
    testa(sockfd);

*  *Other code*
*
*
*
}

void testa(int &sockfd)
{
*
*
*
*  *Other code*
*
*
*

}

void putf(&sockfd)
{
*
*
*
*  *Other code*
*
*
*
test();
test();
sem_post(&mutex);

}

void father(int &sockfd)
{
    while(1)
    {
        srand(time(NULL));
        int ms= rand() % 2000 + 5000
        send(sockfd, DATA, strlen(DATA), 0);
        usleep(1000*ms);
        takef(sockfd);
        putf(sockfd);
    }

}

int main(int argc, char *argv[])
{
*
*
*
*  *Other code*
*
*
*
father(sockfd);

return 0;

}

Or another alternative, like mentioned below, is to write a function prototype. This is similar to how one would write a prototype for functions in a header file and then define the functions in a .cpp file. A function prototype is a function without a body and lets the compiler know the function exists but is not defined yet.

Here is an example using prototyping

sem_t mutex;
sem_t S;
char buffer[1024];
void error(const char *msg)
{
    perror(msg);
    exit(0);
}
/*void signal_callback_handler()
{
    close(sockfd);

}*/

// Prototypes
void takef(int &sockfd);
void testa(int &sockfd);
void putf(&sockfd);

void father(int &sockfd)
{
    while(1)
    {
        srand(time(NULL));
        int ms= rand() % 2000 + 5000
        send(sockfd, DATA, strlen(DATA), 0);
        usleep(1000*ms);
        takef(sockfd);
        putf(sockfd);
    }

}

void takef(int &sockfd)
{

*
*
*  *Other code*
*
*
*
    testa(sockfd);

*  *Other code*
*
*
*
}

void testa(int &sockfd)
{
*
*
*
*  *Other code*
*
*
*

}

void putf(&sockfd)
{
*
*
*
*  *Other code*
*
*
*
test();
test();
sem_post(&mutex);

}

int main(int argc, char *argv[])
{
*
*
*
*  *Other code*
*
*
*
father(sockfd);

return 0;

}