About chown
Command for system V that changes the owner of
a file.
chown [-R] newowner filenames
-R
|
Change
the permission on files that are in the subdirectories of the directory that
you are currently in.
|
newowner
|
The
alias/username of the new owner of the file.
|
filenames
|
The
file that you are changing the rights to.
|
#chown chope file.txt
Give permissions as owner to user chope for the file file.txt.
#chown -R chope work
Give chown permissions to
chope for all files in the work directory.
--------------------------------------------------------------------------------
About chmod
Changes the permission of a file.
chmod [OPTION]... MODE[,MODE]... FILE...
chmod [OPTION]... OCTAL-MODE FILE...
chmod [OPTION]... --reference=RFILE FILE...
chmod [OPTION]... OCTAL-MODE FILE...
chmod [OPTION]... --reference=RFILE FILE...
-c,
--changes
|
like
verbose but report only when a change is made
|
--no-preserve-root
|
do not treat `/' specially (the default)
|
--preserve-root
|
fail
to operate recursively on `/'
|
-f,
--silent, --quiet
|
suppress
most error messages
|
-v,
verbose
|
output
a diagnostic for every file processed
|
--reference=RFILE
|
use
RFILE's mode instead of MODE values
|
-R,
--recursive
|
change
files and directories recursively
|
--help
|
display
this help and exit
|
--version
|
output
version information and exit
|
Permissions
u - User who owns the file.
g - Group that owns the file.
o - Other.
a - All.
r - Read the file.
w - Write or edit the file.
x - Execute or run the file as a program.
g - Group that owns the file.
o - Other.
a - All.
r - Read the file.
w - Write or edit the file.
x - Execute or run the file as a program.
Numeric Permissions:
CHMOD can also to attributed by using Numeric Permissions:
CHMOD can also to attributed by using Numeric Permissions:
400 read by owner
040 read by group
004 read by anybody (other)
200 write by owner
020 write by group
002 write by anybody
100 execute by owner
010 execute by group
001 execute by anybody
040 read by group
004 read by anybody (other)
200 write by owner
020 write by group
002 write by anybody
100 execute by owner
010 execute by group
001 execute by anybody
The above numeric permissions can be added to set a certain
permission, for example, a common HTML file on a Unix or Linux server
accessible over the Internet would be given the below permissions.
#chmod 644 file.htm
This gives the file read/write by the owner
and only read by everyone else (-rw-r--r--).
Files such as scripts that need to be executed
need more permissions. Below is another example of a common permission given to
scripts.
#chmod 755 file.cgi
This would be the following
400+040+004+200+100+010+001 = 755 where you are giving all the rights except
the capability for anyone to write to the file.cgi file(-rwxr-xr-x).
#chmod 666 file.txt
Finally, another common CHMOD permission is
666, as shown below, which is read and write by everyone.
Tip: The above commands are all done through the command line.
However, if you upload a file using FTPthese permissions can
also be adjusted through many FTP clients by right-clicking the file and
choosing permissions.
Below is an example of how a file may be listed when typing ( ls
-l ) at the prompt as well as information on how to interpret it.
-rw-rw-r-- 1 hope 123 Feb 03
15:36 file.txt
-
|
rw
|
rw-
|
r--
|
1
|
hope
|
123
|
Feb
03 15:36
|
file.txt
|
File
|
owner
|
group
|
everyone else
|
links
|
owner
|
size
|
mod date
|
file name
|
