Piping user input into commands in C - c

Question

So I have created a simple shell program which takes input from the user through cmd, and then creates a new task and executes the input as a command. For example:
ls -l /home/user/Downloads | sort –u > listing.txt
But my program can only handle one piping. Can I somehow make it work with no limitations to pipings?? For example:
ls -l /home/user/Downloads | sort –u | wc –l > count.txt
So far I have been unable to implement something like that.
Here is my code:
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/wait.h>
#include <string.h>
#include <stdlib.h>
int main(void)
{
pid_t pid1,pid2,waitPid;
int status,n,j,k,in,out,pdes[2],current_out,current_in,returnValue;
char *token;
char array[256];
char *temp[256];
char *temp2[256];
current_out=dup(1);
current_in=dup(0);
for(;;)
{
if(dup2(current_out,1) < 0)
{
printf("Error restoring output");
}
if(dup2(current_in, 0) < 0)
{
printf("Error restoring input");
}
int i=0;
k=0;
printf("mysh4>");
int check = scanf("%d",&n);
if(check == EOF)
{
printf("You now exit.\n");
break;
}
else
{
fgets(array,sizeof(array),stdin);
array[strcspn(array,"\n")] = 0;
token = strtok(array, " ");
while(token != NULL)
{
temp[i] = token;
token = strtok(NULL, " ");
i++;
k++;
}
temp[i]= NULL;
int p=0;
int qq;
for(i=0;i<k;i++)
{
if(strcmp(temp[i],"|") == 0)
{
for(qq=i+1; qq<k; qq++)
{
temp2[p]=temp[qq];
temp[qq-1] = NULL;
printf("Temp2[%d] is: %s\n" , p , temp2[p]);
printf("Temp1[%d] is: %s\n" , p , temp[p]);
p++;
}
temp2[p]= NULL;
}
}
returnValue=pipe(pdes);
if (returnValue == -1)
{
printf("ERROR: Pipe command failed.\n");
return -1;
}
close(pdes[0]);
close(pdes[1]);
pid1 = fork();
if (pid1 < 0)
{
perror("ERROR: Fork failed.\n");
return -1;
}
//child process
if (pid1 == 0)
{
close(pdes[0]);
dup2(pdes[1],1);
printf("Array:%s", array);
execvp(array,temp);
printf("Invalid Code\n");
return -1;
}
pid2 = fork();
if(pid2 < 0)
{
perror("Error: Fork2 failed.\n");
return -1;
}
//child process 2
if(pid2 == 0)
{
close(pdes[1]);
dup2(pdes[0],0);
for(j=0;j<k;j++)
{
if(strcmp(temp[j],">") == 0)
{
out=j+1;
printf("Output is %s\n", temp[out]);
temp[j] = temp[out];
pdes[1]=open(temp[out],
O_APPEND | O_RDWR | O_CREAT, S_IRUSR | S_IWUSR);
if(dup2(pdes[1],1) < 0)
{
printf("error in dup2");
return -1;
}
}
}
execvp(temp2[0],temp2);
printf("Invalid Code 2\n");
return -1;
}
//father process
else
{
//father waits child process to finish
waitPid = wait(NULL);
if (waitPid == -1)
{
perror("ERROR: Waitpid failed.\n");
return -1;
}
}
}
}
return 0;
}