If UMASK is set to 0077 or 0007, then the default permissions for new directories are 700 0r 770. Then what is the default permission for a new file..

Have a look here: Default permissions of newly created directories - post #4

This is one of those things you could have tried for yourself and got a definite answer in about the time it takes to type the question here.

umask............. file permissions ................. directory permissions
077 .......................... 600 ............................. 700
007 .......................... 660 ............................. 770
777 .......................... 000 ............................. 000

the rules in deciding what will be the permissions for newly created files & dir are

rule1:subtract the umask from default permissions to get effective permissions

.......: default file permission 666 default dir permission 777
............umask (for example) - 002 ..............................- 002
-----------------------------------------------------------------------------------------------------------------
effective permission............... 664 ................................ 775
---------------- ------------------

rule2 : newly created files can not have ëxecutable bit set

default file permission 666 default dir permission 777
umask (for example) - 077 (will be treated as 066) - 077
---------------- ------------------
effective permission 600 700
---------------- ------------------

default file permission 666 default dir permission 777
umask (for example) - 007 (will be treated as 006) - 007
---------------- ------------------
effective permission 660 770
---------------- ------------------

2 members found this post helpful.

Not true. It depends on what the program creating the file asks for. A program must specify something in the mode argument when creating a file, and whatever value it puts there will be modified by umask and used as the permissions. Programs used primarily for non-executable files will usually use 0666 unless security concerns indicate that something stricter would be appropriate (e.g., programs that manage encryption keys). Programs like the linker (ld) that create executable files commonly use 0777.

when you are normally creating a file using "vi", "touch", "cat" or by redirecting the output
or creating directories using "mkdir"

the 2 above mention rule mentioned in previous post will come into picture.