How do I solve "expected a ';' in C" - c

Question

I'm trying to finish my network programming practice. And I came through this problem which I couldn't fix. It might seem stupid but I had spent an afternoon on it. I would really appreciate if anyone could help me out.
Here is the code, the error is within #ifdef process_conn_server_2 segment.
#include <stdio.h>
#include <sys/uio.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <fcntl.h>
#include <sys/types.h>
#include "process_num.c"
#define process_conn_client_2
#define process_conn_server_2
static struct iovec *vs = NULL,
*vc = NULL;
void sig_process(int signo)
{
printf("Catch ax exit signal\n");
free(vc);
free(vs);
_exit(0);
}
void sig_pipe(int signo)
{
printf("Catch a SIGPIPE signal\n");
free(vc);
free(vs);
_exit(0);
}
#ifdef process_conn_client_0
void process_conn_client(int s)
{
ssize_t size = 0;
char buffer[1024];
for (;;)
{
size = read(0, buffer, 1024);
// size = recv(s, buffer, 1024, 0);
if (size > 0)
{
send(s, buffer, size, 0);
size = recv(s, buffer, 1024, 0);
write(1, buffer, size);
}
}
}
#endif // read、send、write
#ifdef process_conn_client_1
void process_conn_client(int s)
{
char buffer[30];
ssize_t size = 0;
struct iovec *v = (struct iovec *)malloc(3 * sizeof(struct iovec));
if (!v)
{
printf("Not enough memory\n");
return;
}
vc = v;
v[0].iov_base = buffer;
v[1].iov_base = buffer + 10;
v[2].iov_base = buffer + 20;
v[0].iov_len = v[1].iov_len = v[2].iov_len = 10;
int i = 0;
for (;;)
{
size = read(0, v[0].iov_base, 10);
if (size > 0)
{
v[0].iov_len = size;
writev(s, v, 1);
v[0].iov_len = v[1].iov_len = v[2].iov_len = 10;
size = readv(s, v, 3);
for (i = 0; i < 3; i++)
{
if (v[i].iov_len > 0)
{
write(1, v[i].iov_base, v[i].iov_len);
}
}
}
}
}
#endif // read writev readv
#ifdef process_conn_client_2
void process_conn_client(int s)
{
char buffer[30];
ssize_t size = 0;
struct msghdr msg;
struct iovec *v = (struct iovec *)malloc(3 * sizeof(struct iovec));
if (!v)
{
perror("wrong: allocate memory\n");
return;
}
msg.msg_name = NULL;
msg.msg_namelen = 0;
msg.msg_control = NULL;
msg.msg_controllen = 0;
msg.msg_iov = v;
msg.msg_iovlen = 3;
msg.msg_flags = 0;
vc = v;
v[0].iov_base = buffer;
v[1].iov_base = buffer + 10;
v[2].iov_base = buffer + 20;
v[0].iov_len = v[1].iov_len = v[2].iov_len = 10;
// int fd;
for (;;)
{
// fd = open("firstfile.txt", O_RDONLY, 0666);
size = read(0, v[0].iov_base, 10);
printf("%d size\n", size);
if (size > 0)
{
v[0].iov_len = size;
if (sendmsg(s, &msg, 0) < 0)
{
perror("");
return;
}
v[0].iov_len = v[1].iov_len = v[2].iov_len = 10;
memset(v[0].iov_base, '\0', v[0].iov_len);
memset(v[1].iov_base, '\0', v[1].iov_len);
memset(v[2].iov_base, '\0', v[2].iov_len);
size = recvmsg(s, &msg, 0);
for (int i = 0; i < 3; i++)
{
if (v[i].iov_len > 0)
{
write(1, v[i].iov_base, v[i].iov_len);
write(1, '\n', 1);
}
}
memset(v[0].iov_base, '\0', v[0].iov_len);
memset(v[1].iov_base, '\0', v[1].iov_len);
memset(v[2].iov_base, '\0', v[2].iov_len);
}
}
#endif // sendmsg recvmsg
#ifdef process_conn_server_0
void process_conn_server(int s)
{
ssize_t size = 0;
char buffer[1024];
float result;
for (;;)
{
// size = read(s, buffer, 1024);
size = recv(s, buffer, 1024, 0);
if (size == 0)
{
return;
}
printf("received %s", buffer);
result = process_num(buffer);
if (result == 65535)
{
sprintf(buffer, "%d bytes in total.\n", size);
}
else
{
printf("%f\n", result);
sprintf(buffer, "the result is %f.\n", result);
}
//write(s, buffer, strlen(buffer) + 1);
send(s, buffer, strlen(buffer) + 1, 0);
memset(buffer, '\0', sizeof(buffer));
}
}
#endif //recv send
#ifdef process_conn_server_1
void process_conn_server(int s)
{
char buffer[30];
ssize_t size = 0;
struct iovec *v = (struct iovec *)malloc(3 * sizeof(struct iovec));
if (!v)
{
printf("Not enough memory\n");
return;
}
vs = v;
v[0].iov_base = buffer;
v[1].iov_base = buffer + 10;
v[2].iov_base = buffer + 20;
v[0].iov_len = v[1].iov_len = v[2].iov_len = 10;
for (;;)
{
size = readv(s, v, 3);
if (size == 0)
{
return;
}
sprintf(v[0].iov_base, "%d ", size);
sprintf(v[1].iov_base, "bytes alt");
sprintf(v[2].iov_base, "ogether\n");
v[0].iov_len = strlen(v[0].iov_base);
v[1].iov_len = strlen(v[1].iov_base);
v[2].iov_len = strlen(v[2].iov_base);
writev(s, v, 3);
}
}
#endif // readv writev
#ifdef process_conn_server_2
void process_conn_server(int s)
{ //this is where the error appears
char buffer[30];
ssize_t size = 0;
struct msghdr msg;
struct iovec *v = (struct iovec *)malloc(3 * sizeof(struct iovec));
if (!v)
{
perror("wrong: allocate memory\n");
return;
}
msg.msg_name = NULL;
msg.msg_namelen = 0;
msg.msg_control = NULL;
msg.msg_controllen = 0;
msg.msg_iov = v;
msg.msg_iovlen = 3;
msg.msg_flags = 0;
vs = v;
v[0].iov_base = buffer;
v[1].iov_base = buffer + 10;
v[2].iov_base = buffer + 20;
v[0].iov_len = v[1].iov_len = v[2].iov_len = 10;
for (;;)
{
size = recvmsg(s, &msg, 0);
if (size == 0)
{
return;
}
sprintf(v[0].iov_base, "%d ", size);
sprintf(v[1].iov_base, "bytes alt");
sprintf(v[2].iov_base, "ogether\n");
v[0].iov_len = strlen(v[0].iov_base);
v[1].iov_len = strlen(v[1].iov_base);
v[2].iov_len = strlen(v[2].iov_base);
for (int i = 0; i < 3; i++)
{
if (v[i].iov_len > 0)
{
write(1, v[i].iov_base, v[i].iov_len);
write(1, '\n', 1);
}
}
sendmsg(s, &msg, 0);
memset(v[0].iov_base, '\0', v[0].iov_len);
memset(v[1].iov_base, '\0', v[1].iov_len);
memset(v[2].iov_base, '\0', v[2].iov_len);
}
}
#endif
I dont't know if this would be of any help but the code works just fine when I
define process_conn_server/client 0/1 instead of 2.

Answer 1

when process_conn_client_2 is defined, you don't seem to close process_conn_client(), therefore opening another function after that gives you an error. You can see that from the indentation

Answer 2

Just for total clarification. There is missing a closing bracket } at the end of the definition of process_conn_client_2 to terminate the function definition. Hence the error.
I marked the place of issue with the correct placed } in this snippet:
#ifdef process_conn_client_2
void process_conn_client(int s)
{
char buffer[30];
ssize_t size = 0;
struct msghdr msg;
struct iovec *v = (struct iovec *)malloc(3 * sizeof(struct iovec));
if (!v)
{
perror("wrong: allocate memory\n");
return;
}
msg.msg_name = NULL;
msg.msg_namelen = 0;
msg.msg_control = NULL;
msg.msg_controllen = 0;
msg.msg_iov = v;
msg.msg_iovlen = 3;
msg.msg_flags = 0;
vc = v;
v[0].iov_base = buffer;
v[1].iov_base = buffer + 10;
v[2].iov_base = buffer + 20;
v[0].iov_len = v[1].iov_len = v[2].iov_len = 10;
// int fd;
for (;;)
{
// fd = open("firstfile.txt", O_RDONLY, 0666);
size = read(0, v[0].iov_base, 10);
printf("%d size\n", size);
if (size > 0)
{
v[0].iov_len = size;
if (sendmsg(s, &msg, 0) < 0)
{
perror("");
return;
}
v[0].iov_len = v[1].iov_len = v[2].iov_len = 10;
memset(v[0].iov_base, '\0', v[0].iov_len);
memset(v[1].iov_base, '\0', v[1].iov_len);
memset(v[2].iov_base, '\0', v[2].iov_len);
size = recvmsg(s, &msg, 0);
for (int i = 0; i < 3; i++)
{
if (v[i].iov_len > 0)
{
write(1, v[i].iov_base, v[i].iov_len);
write(1, '\n', 1);
}
}
memset(v[0].iov_base, '\0', v[0].iov_len);
memset(v[1].iov_base, '\0', v[1].iov_len);
memset(v[2].iov_base, '\0', v[2].iov_len);
}
}
} // <------- HERE
#endif // sendmsg recvmsg
I voted to close this question as caused by typo.