Question

1.Below is the output of the command ls –l report

-rw-rw-r--+ 1 max pubs 9537 01-12 23:17 report

Explain the meaning of the first field (i.e. -rw-rw-r--+)

2.Provide the command to modify the permissions on the file report above so that the user sam has read-only permission, and the user zach has read & write permissions

3.Provide the command to remove the rule that gives sam permission to access the file report

Answer 1

Answer :
1)

ls command is used to list out the available file.

ls -l gives all the details of the files.

When we use ls -l command then, following is the structure for every file : d rwx rwx rwx

d : file type (directory)

- : Normal files that contain data

rwx : r(read) w(write) x(execute) permissions

first rwx group stand for User (Owner of the file)

second rwx group stands for Group (files belonging to that group )

third rwx group stands for Other (Any user)

-rw-rw-r--+ 1 max pubs 9537 01-12 23:17 report
-rw-rw-r-- : Normal file having read and write permission to User and Group but other users having only read permission.

1 : Indicates number of file/directory contained in that directory/file. Here only one file is available.

max : Owner of file having read/write permission

pubs : File belongs to pubs group having read/write permission

9537 : Size of the file

01-12 23:17 : Date and Time, when the file created

report : File name

2)

To change the permission use chmod command.

Commds for user sam has only read permission:

chown sam:pubs report

chmod 004 report

Commds for user zach has read and write permission:

chown zach:pubs report

chmod 006 report

3)

chown sam:pubs report

chmod 000 report

chown max:pubs report

Now user sam dont have permission to read/write or execute a report file.