Shell Programming and Scripting

#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include <unistd.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <string.h>

main(int argc, char* argv[]) {
    int nr, i, fd[2];
    pipe(fd);   //make the pipe 
    struct stat st;
    struct stat s; 
    FILE *f;
    FILE *f2; 
    int status;
    char path[50];

//start parsing the arguments 
for (i = 1; i < argc; i++) {
//creating a subprocess
    if (fork() == 0) {

        if(stat(argv[i],&s)==0)
        {     //testing if file 
            if (s.st_mode & S_IFREG)
            {
                stat(argv[i],&st);
                nr=st.st_size;  
                printf("size of file %s is %d\n",argv[i],nr);   
                write(fd[1],&nr,sizeof(int));    
                close(fd[0]);
                close(fd[1]);

            }
            else if(s.st_mode & S_IFDIR) //testing if directory
            { 
                f=popen("find argv[i] -type f | wc -l", "r");
                if (f==NULL){
                    printf("popen error");
                }
                if (fgets(path,10,f)!=NULL){
                    fscanf(f,"%d",&nr); 
                }
                status=pclose(f);
                if (status==-1){
                    printf("error closing popen");
                }                
                printf("nr of files in directory %s is %d\n",argv[i],nr);   
                write(fd[1],&nr,sizeof(int));
                close(fd[0]);
                close(fd[1]);

            }
        }   
       else
       {
              //getting a random generated number 
            nr = rand() % 15 + 5; 
            printf("a random generated number: %d\n",nr);
            write(fd[1],&nr,sizeof(int));
            close(fd[0]);
            close(fd[1]);   
       }

        // here ends every subprocess 
    }
//closing the pipe 
close(fd[0]);
close(fd[1]);
}

// parent receives what the subprocesses sent 
for (i = 1; i < argc; i++) {
    read(fd[0],&nr,sizeof(int));
    printf("the parent received: %d\n",nr);
    close(fd[0]);
    close(fd[1]);
}    
close(fd[0]);
close(fd[1]);
return 0;
}