chmod - change file mode bits
numeric method
r (read) = 4
w (write) = 2
x (execute) = 1
no permissions = 0
rwx=4+2+1=7
rw= 4+2=6
rx= 4+1=5
To set read , write , execute permission to users , group and others
$ chmod 777 file_name
To set read , write , execute permission to users and read permission only
for group and others
$ chmod 744 file_name
To set users read, write and execute permissions, read and execute
permissions to group members and no permissions to all other users
$ chmod 750 file_name
To recursively set read, write, and execute permissions to the file owner
and no permissions for group and all other users on a given directory
$ chmod -R 700 dir_name
To set the file’s permissions to be same for (file2_name) as those of the
specified reference file (file1_name)
$ chmod --reference=file1_name file2_name
To set the permissions of all files and subdirectories under the /var/www
to 700
$ chmod -R 700 /var/www
To set read, write, and execute permissions, and a sticky bit to a given
directory
$ chmod 1777 dir_name
regards,
T.Dhanasekar