creating unknown amount of process in child without pipe and semaphore - c

Question

I am trying to make a modified shell.
I have tried several times, I searched a lot on the net, but I cannot fix my problem. first of all I do not want to run this code by pipe or semaphore.
I think with semaphore it would be even more difficult, because I do not now how many process should be there (maybe I am wrong, but it seems at least in this way).
In the first way, program makes the file correctly, but I cannot run a loop until the user enter "exit". I am trying with while(1) but it does not give me more than one file and the stdin is active only once.
in the second way, the user can use stdin until he inserts "exit", but again,
it does not give more than one file, moreover there is nothing inside.
I am trying to mix these two ways, I tried for more than one day, but I do not understand where is the problem. By the way, I think in the second way,
it should be the file descriptor.
also, please let me know that do I use the wait system call correctly or not?
Thank you in advance.
/first way/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <dirent.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <string.h>
#include <fcntl.h>
//void MYshell(char *comm);
int main(){
/*
char cmd[100];
printf("<exit> closes shell\n");
printf("MYshell:$ ");
fscanf(stdin,"%s",cmd);
do{
if(strcmp(cmd,"exit")==0){
printf("shell has been closed.\n");
break;
exit(EXIT_SUCCESS);
}
MYshell(cmd);
printf("MYshell:$ ");
fscanf(stdin,"%s",cmd);
}while(1);
*/
//void MYshell(char *comm){
pid_t fork_ret;
int fd,dup_ret;
char cmd[100];
char name[100];
printf(" <exit> closes shell\n");
printf("MYshell:$ ");
fscanf(stdin,"%s",cmd);
if(strcmp(cmd,"exit")==0){
printf("shell has been closed.\n");
//break;
exit(EXIT_SUCCESS);
}
fork_ret = fork();
if(fork_ret == -1)
exit(1);
if(fork_ret == 0){
sprintf(name,"%d.log",getpid());
fd = open(name,O_CREAT | O_WRONLY,S_IRWXU|S_IRWXG|S_IRWXO);
if(fd<0){
printf("Error in opening or creating %s.\n",name);
exit(1);
}
dup_ret = dup2(fd,1);
if(dup_ret<0){
printf("Error in duplicating stdout descriptor.\n");
exit(1);
}
system(cmd);
close(fd);
exit(0);
}
//close(fd);
//exit(EXIT_SUCCESS);
if(fork_ret>0){
int stat;
pid_t child = wait(&stat);
printf("child = %d\n",child);
if(WIFEXITED(stat))
printf("ok\n");
else
printf("error\n");
}
wait(NULL);
exit(EXIT_SUCCESS);
}
/* second way*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <dirent.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <string.h>
#include <fcntl.h>
int fd;
char cmd[100];
void MYshell(void);
int main(){
pid_t fork_ret;
//int fd,dup_ret;
printf(" <exit> closes shell\n");
while(1){
printf("MYshell:$ ");
fscanf(stdin,"%s",cmd);
//tmp = fgets(cmd,sizeof(cmd),stdin);
if(strcmp(cmd,"exit")==0){
printf("shell has been closed.\n");
break;
exit(EXIT_SUCCESS);
}
}
fork_ret = fork();
if(fork_ret == -1)
exit(1);
if(fork_ret == 0){
MYshell();
exit(0);
}
if(fork_ret>0){
wait(NULL);
exit(0);
}
wait(NULL);
exit(EXIT_SUCCESS);
}
void MYshell(void){
char name[BUFSIZ];
int fd,dup_ret;
sprintf(name,"%d.log",getpid());
fd = open(name, O_CREAT|O_RDWR , S_IRWXU|S_IRWXG|S_IRWXO);
if(fd<0){
printf("Error in opening or creating %s.\n",name);
exit(1);
}
dup_ret = dup2(fd,1);
if(dup_ret<0){
printf("Error in duplicating stdout descriptor.\n");
exit(1);
}
system(cmd);
close(fd);
exit(0);
}