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