File Permissions in Linux

File Permissions

Ability to restrict/control access to files.

File Type Permission

10 bits represents , ability to restrict/control.

ls -l to examine permissions

-rwxrwxr-x

bits order

1.      =file type "- file , d directory"

rwx

2-4.   = owner's permissions

 r=read =4

 w=write =2 ==>> 7

 x=execute=1

- = none = 0

rwx

5 - 7  = group owner's permissions

 r= read = 4

 w= write =2 ==> 7

 x=execute =1

 - = none =0

r-x

8 - 10  = everyone permissions

 r= read = 4

 w= write =2 ==> 5

 x=execute =1

-=none=0

chmod 664

chmod 775

user = u

other =o everyone

group=g

chmod  u+rwx ( user read+write +execute)

chmod a+rwx   everyone 777

prefix 5

755

chmod 2755 /sales

mkdir /sales

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chown = permits changing of ownership                                     of files

chown -R newowner filenames

R= recursive

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/var/www/html

change ownership of different files.

chown apache:apache /var/www/html -R