110/getdents.c

#include <errno.h>
#include <string.h>
#include <sys/stat.h>
#include <a.out.h>

#include <linux/fs.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <asm/segment.h>

struct linux_dirent {
	long           d_ino;
	off_t          d_off;
	unsigned short d_reclen;
	char           d_name[14];
};

int sys_getdents(unsigned int fd, struct linux_dirent *d, unsigned int count)
{
    struct file  *f;
	struct m_inode * m;
    struct buffer_head * b;
    struct dir_entry * dir;
	int i,j,k,res;
    struct linux_dirent usrd;
    i=0;
    res=0;
    f=current->filp[fd];
    m=f->f_inode;
    b=bread(m->i_dev,m->i_zone[0]);
    dir=(struct dir_entry*)b->b_data;
    while(dir[i].inode>0)
    {
        if(res+sizeof(struct linux_dirent)>count)
            break;
        usrd.d_ino=dir[i].inode;
        usrd.d_off=0;
        usrd.d_reclen=sizeof(struct linux_dirent);
        for(j=0;j<14;j++)
            usrd.d_name[j]=dir[i].name[j];
        for(k=0;k<sizeof(struct linux_dirent);k++)
        {
            put_fs_byte(((char*)(&usrd))[k],(char*)d+res);
            res++;
        }
        i++;
    }
    return res;
}

char *sys_getcwd(char* buf,size_t size)
{
	char *path[14];
    int i,j,k,l,dev,inum;
    struct m_inode *inode;
    struct buffer_head *b;
    struct dir_entry *d;
    dev=current->root->i_dev;
    inode=current->pwd;
    inum=inode->i_num;
    b=bread(dev,inode->i_zone[0]);
    d=(struct dir_entry*) b->b_data;
    i=0;
    l=0;
    while(inum!=1)
    {
        inode=iget(dev, d[1].inode);
        b=bread(dev,inode->i_zone[0]);
        d=(struct dir_entry*) b->b_data;
        j=0;
        while(d[j].inode!=inum) j++;
        inum=inode->i_num;
        path[i]=d[j].name;
        i++;
    }
    while(i>0)
    {
        i--;
        put_fs_byte('/',buf+l);
        l++;
        k=0;
        while(path[i][k]!='\0')
        {
            put_fs_byte(path[i][k],buf+l);
            l++;
            if(l>=size) break;
            k++;
        }
        if(l>=size) break;
    }
    return buf;
}