umask - is used to set default permissions for files or directories the
user creates.
To calculate umask value
$ umask
To Displays the current mask
$ umask -p
To set and update the default umask value
$ umask 543
To view symbolic representation
$ umask -S
To set the default permissions for all new files or folders to 644 and 755
then umask value is
$ umask 022
for folders 777-022 = 755
for files 666-022 = 644
regards,
T.Dhanasekar