Random function working on Linux not on Mac - c

Question

I'm currently learning network programming in university and programmed a server. As we need this one for further progress I need to reuse the code every time. There is a random function with an error I don't really get because on the linux pcs at university everything compiles well only my mac which I do all my homework shows this error.
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <arpa/inet.h>
#include <sys/wait.h>
#include <signal.h>
#include <time.h>
//#define PORT "3490" // the port users will be connecting to
#define BACKLOG 10 // how many pending connections queue will hold
int random(int min, int max){
srand ( time(NULL) );
return min + rand() / (RAND_MAX / (max - min + 1) + 1);
}
void sigchld_handler(int s)
{
// waitpid() might overwrite errno, so we save and restore it:
int saved_errno = errno;
while(waitpid(-1, NULL, WNOHANG) > 0);
errno = saved_errno;
}
// get sockaddr, IPv4 or IPv6:
void *get_in_addr(struct sockaddr *sa)
{
if (sa->sa_family == AF_INET) {
return &(((struct sockaddr_in*)sa)->sin_addr);
}
return &(((struct sockaddr_in6*)sa)->sin6_addr);
}
int main(int argc, char *argv[])
{
int sockfd, new_fd; // listen on sock_fd, new connection on new_fd
struct addrinfo hints, *servinfo, *p;
struct sockaddr_storage their_addr; // connector's address information
socklen_t sin_size;
struct sigaction sa;
int yes=1;
char s[INET6_ADDRSTRLEN];
int rv;
//int linetoread;
if (argc != 3) {
fprintf(stderr,"usage: server port txtfile\n");
exit(1);
}
FILE* fp;
char buffer[255];
int i = 0;
char rnd[200][255];
int fixed;
fp = fopen(argv[2], "r");
while(fgets(buffer, 255, (FILE*) fp)) {
//printf("%s\n", buffer);
for (int j = 0; j < 255; j++){
rnd[i][j] = buffer[j];
}
i++;
}
fclose(fp);
//printf("number of lines: %d\n", i);
//linetoread = rand() % i;
//printf("%d\n", random(0,i));
memset(&hints, 0, sizeof hints);
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
hints.ai_flags = AI_PASSIVE; // use my IP
if ((rv = getaddrinfo(NULL, argv[1], &hints, &servinfo)) != 0) {
fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(rv));
return 1;
}
// loop through all the results and bind to the first we can
for(p = servinfo; p != NULL; p = p->ai_next) {
if ((sockfd = socket(p->ai_family, p->ai_socktype,
p->ai_protocol)) == -1) {
perror("server: socket");
continue;
}
if (setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &yes,
sizeof(int)) == -1) {
perror("setsockopt");
exit(1);
}
if (bind(sockfd, p->ai_addr, p->ai_addrlen) == -1) {
close(sockfd);
perror("server: bind");
continue;
}
break;
}
freeaddrinfo(servinfo); // all done with this structure
if (p == NULL) {
fprintf(stderr, "server: failed to bind\n");
exit(1);
}
if (listen(sockfd, BACKLOG) == -1) {
perror("listen");
exit(1);
}
sa.sa_handler = sigchld_handler; // reap all dead processes
sigemptyset(&sa.sa_mask);
sa.sa_flags = SA_RESTART;
if (sigaction(SIGCHLD, &sa, NULL) == -1) {
perror("sigaction");
exit(1);
}
printf("server: waiting for connections...\n");
while(1) { // main accept() loop
sin_size = sizeof their_addr;
new_fd = accept(sockfd, (struct sockaddr *)&their_addr, &sin_size);
if (new_fd == -1) {
perror("accept");
continue;
}
inet_ntop(their_addr.ss_family,
get_in_addr((struct sockaddr *)&their_addr),
s, sizeof s);
printf("server: got connection from %s\n", s);
if (!fork()) { // this is the child process
close(sockfd); // child doesn't need the listener
fixed = random(0,i-1);
//printf("line: %d\n", fixed);
if (send(new_fd, rnd[fixed], strlen(rnd[fixed]), 0) == -1)
perror("send");
close(new_fd);
exit(0);
}
close(new_fd); // parent doesn't need this
}
return 0;
}
Error on my mac:
server.c:16:5: error: conflicting types for 'random'
int random(int min, int max){
^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.13.sdk/usr/include/stdlib.h:233:7: note:
previous declaration is here
long random(void) __swift_unavailable("Use arc4random instead.");
^
server.c:132:19: error: too many arguments to function call, expected 0, have 2
fixed = random(0,i-1);
~~~~~~ ^~~~~
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.13.sdk/usr/include/stdlib.h:233:1: note:
'random' declared here
long random(void) __swift_unavailable("Use arc4random instead.");
^
2 errors generated.

Answer 1

random() is a known function name. change it to something else and it will work.