OS lab 3

lab3 : implementing ls command


system calls:

-mkdir
-opendir
-readdir
-rmdir
-closedir
-getcwd


aim: print pwd

pwd.c

#include<stdio.h>
#include<stdlib.h>
#include<unistd.h>
#define BUFF 1024

int main()
{
    char buf[BUFF];

    if(getcwd(buf,sizeof(buf))!=NULL)
    {
        printf("%s\n",buf);
    }
    else
    {
        printf("Error.");
    }
    return 0;
}


aim:ls without hidden

#include<stdio.h>
#include<stdlib.h>
#include<unistd.h>
#include<dirent.h>
#include<sys/types.h>
#define BUFF 1024

int main()
{
    char buf[BUFF];
    DIR *dirstream;
    struct dirent *d;

    if(getcwd(buf,sizeof(buf))!=NULL)
    {
        if((dirstream=opendir(buf))!=NULL)
        {
            while((d=readdir(dirstream))!=NULL)
            {
                if((d->d_name)[0]!='.')
                printf("%s\n",d->d_name);
            }
        }
        else
        {
            printf("Error.\n");
            exit(1);
        }
    }
    else
    {
        printf("Error.\n");
        exit(1);
    }




    return 0;
}




*/recursive



#include<stdio.h>
#include<stdlib.h>
#include<unistd.h>
#include<dirent.h>
#include<sys/types.h>
#include<string.h>
#define BUFF 4096
void print(char* buf)
{
    char buf2[BUFF];
    DIR *dirstream,*dirstream2;
    struct dirent *d;
    printf("%s\t:\n",buf);

        if((dirstream=opendir(buf))!=NULL)
        {
            while((d=readdir(dirstream))!=NULL)
            {
                if((d->d_name)[0]!='.')
                {
                    printf("%s\n",d->d_name);
                }
            }


            if((dirstream2=opendir(buf))!=NULL)
            {
                while((d=readdir(dirstream2))!=NULL)
                {
                    if(d->d_type == DT_DIR)
                    {
                        if(d->d_name[0]!='.')
                        {
                            if((chdir(d->d_name))==0 )
                            {
                                getcwd(buf2,sizeof(buf2));
                                print(buf2);
                            }
                        }
                    }
                }
            }



        }
        else
        {
            printf("Error.1\n");
            exit(1);
        }
}

int main()
{
    char buf[BUFF];

    if(getcwd(buf,sizeof(buf))!=NULL)

    {

        print(buf);
    }
    else
    {
        printf("Error.\n");
        exit(1);
    }




    return 0;
}