Listing of Folders (ls): -

Q) Which command will list the files and sub – directories present inside a directory ?

Ans - $ ls<Enter – Key>

Q) How we list the hidden files with other files and sub – directories present inside a directory ?

Ans - $ ls –a<Enter – Key>

Q) How we long list i.e. the detail information about a file or sub – directories present

inside a directory ?

Ans - $ ls -l<Enter – Key>

Q) How many columns are present for a file or sub – directories present inside a directory

during long listing of the directories ?

Ans – There are 9 columns information present for a file or sub – directory of a directory

during its long listing.

Such as –

1. File Type and Permission –> This column gives which file type is it and its corresponding permission given to owner, group and other.

2. No of links –> This column gives number of links connected to the corresponding

file or sub - directory.

3. User Login Name I.e. User ID –> Give Login ID of Owner

4. Group ID –> Give the group id in which Owner of the file belongs

5. File or Sub – directory Size –>Give size of file or sub – directory in block or bytes. 1 Block = 512 bytes

6. Modification Month –> In which month the file is modified last time

7. Modification Date –> In which date the file is modified last time

8. Last Modification Time –> In which time the file is modified last time

9. File or Sub – directory Name -> Corresponding file or sub – directory name

Q) What are different types of file present in Unix ?

Ans – Below are different types of file present in Unix.

1. Ordinary File (-)

2. Directory File (d)

3. Character Device File (c)

4. Block Device File (b)

5. Local Socket File (s)

6. Named Pipe (p)

7. Symbolic Link (l)

Q) How you know which file is related which file type ?

Ans - $ file <File Name><Enter – Key>

Q) Give details explanation about file type and file permission column present as 1^st column during

long listing of a directory ?

Ans – File Type and File Permission field contains 10 characters.

1^st Character – File type symbol I.e. if ordinary file, then the 1^st character will be ‘–‘  or if

directory file, then ‘d’ and so on.

2^nd , 3^rd and 4^th Character – Owner’s read(r), write(w) and execute(x) permission.

I.e. if Owner have read, write and no execute permission on the file, then 2^nd , 3^rd and 4^th character will be rw-.

5^th ,6^th and 7^th Character – Group User’s read (r), write (w) and execute (x) permission.
I.e. if group have read, no write and execute permission on the file, then 5^th , 6^th and 7^th character will

be r-x.

8^th ,9^th and 10^th Character – Other User’s read (r), write (w) and execute (x) permission.

I.e. if other have no read, no write and execute permission on the file, then 8^th , 9^th and 10^th character will be --x.

Q) Which command will long list the directory content based on modification time ?

Ans - $ ls –lt<Enter – Key>

Q) Which command will long list the directory content in such a way that files and sub – directories available in ascending order based on the modification time i.e. latest modified file will be available in the end of the listing of directory content ?

Ans - $ ls –lrt<Enter – Key>

Where r -> reverse

Q) Which command will long list the directory content based on access time ?

Ans - $ ls –lu<Enter – Key>

Q) Which command will long list the directory content based on size column in human readable format ?

Ans - $ ls –lh<Enter – Key>

Where h->human readable format

Q) How we see the sub – directories content and files of a directory i.e Recrusively ?

Ans - $ ls –R<Enter – Key>

If we go for long listing of above command, then $ ls –lR<Enter – Key>