You can find the umask value in your Linux account by typing "umask" on the command line:
$ umask
0077
The value on umask in a Linux server level is defined in file /etc/login.defs (or maybe in /etc/profile, /etc/bashrc or /etc/cshrc). But you can set up your own umask in .profile for your account.
$ more /etc/login.defs
MAIL_DIR /var/spool/mail
PASS_MAX_DAYS 90
PASS_MIN_DAYS 7
PASS_WARN_AGE 7
PASS_MIN_LEN 8
UID_MIN 1000
UID_MAX 60000
GID_MIN 1000
GID_MAX 60000
CREATE_HOME yes
UMASK 077
USERGROUPS_ENAB yes
ENCRYPT_METHOD sha512
Under 0077, any file you created will have "-rw-------" permission, which means only yourself can read and write it.
$ touch test1.del
$ ls -al test1.del
-rw-------. 1 userID Group 0 Feb 02 13:25 test1.del
Sometimes, it is necessary for other users to read or modify a file created by a service account or you want others to read your files. To change the default from server level, you can add one line to the account's .profile:
$ vi $HOME/.profile
umask u=rwx,g=rwx,o=rx
or
umask 0002
After re-login, umask will change to 0002 in the account. Then, any file created by that account will get "-rw-rw-r--" permission.
$ umask
0002
$ touch test2.del
$ ls -al test2.del
-rw-rw-r--. 1 userID Group 0 Feb 02 13:55 test2.del
Now, other users can read it.
If you put "umask u=rwx,g=rwx,o=rwx" or "umask 0000" in .profile, any new file will get "-rw-rw-rw-" permission (666).
$ vi $HOME/.profile
umask u=rwx,g=rwx,o=rwx
$ umask
0000
$ touch test3.del
$ ls -al test3.del
-rw-rw-rw-. 1 userID Group 0 Feb 02 15:55 test3.del
If you have "umask 0022" in the profile, new file will get permission "-rw-r--r--".
Note that "x" in the .profile only applies to new folder creation. Linux allows only manually to grant executable to a file.
