Gather File permission during scripting on unix as numbers.

Shell Programming and Scripting
1

Hi,

I have a script with following file permission on box.
-rwxr-xr-x 1 root system 15347 Aug 14 15:08 b_reboot.ksh

Without calculating or watching at -rwxr-xr-x (permission's) of this above mentioned file. I would like to get the file permission assigned to a file.

Basically looking for after issuing some commands <file name>, I should get the permission of provided file in a variable as 755. (as a number, either 755/644..or what ever it is.)

Example,

$some_command <file_name>
$permission=$?

And the output which I looking forward is like this.
$print ${permission}
755

Do we have any command which can substitute "some_command" like this on Unix.?

Note:
------
I don't like to go for the manipulation using the ls -l |grep <filename> |awk '{print $1}'
Looking for any thing which can be easily done to retrieve permission of file in numbers.

2

do you mean set file permissions to 755?

chmod 755 filename

If you mean get the permissions, and you are in Linux check out the stat command.  That would be 
man 1 stat 
#or
stat --help
3

from what I read, ajilesh is wanting to see what the permissions are in a non-volatile way. I don't know how you do this in csh, but in ksh you can do this:

if [[ -x /usr/lib/sendmail ]] this is true if the user doing the condition, can execute /usr/lib/sendmail
if [[ -r /usr/lib/sendmail ]] this is true if the user doing the condition, can read /usr/lib/sendmail
if [[ -w /usr/lib/sendmail ]] this is true if the user doing the condition, can write /usr/lib/sendmail

but this only checks the permissions of the user performing the, in this case, if/then/else has those permissions. I do not know of any way to convert rwxrw-rw- to the octal 755 to then confirm you have the correct permissions on said file or directory. I have run into this same problem in my own scripting because the file I was checking on needed to be 766 and I was trying to track down when the permissions got changed so I could figure out what was changing the permissions, the only option I found was to ls -l <file> then pipe that into a grep on "rwxrw\-rw\-" to confirm (yes, \- is necessary to ensure it doesn't try to treat -rw as an option some how) it had the correct permissions.

while using chmod is a good suggestion, chmod sets the permissions without regard to the previous state.

4

James, well, you are correct. I'm looking for any way to convert rwxrw-rw- to the octal 755.. Do we have any internal unix commands where we can trace the octal which is assigned to a file or directory directly.

5

find . -name "*" -maxdepth 1 -printf '%m %p\n'
or
stat -c "%a %n" *

6

both are not working in AIX..:confused:

7

If you have Perl, you can use that as a workaround.

perl -e 'for (@ARGV) { printf "%04o %s",  (stat)[2] & 07777, $_ }' files ...
8

oh great it worked...
is there any other command than stat command in unix??