Umask of Linux system default permissions

By default, the directory permission value is 755, the normal file permission value is 644, then this value is determined by WHO, the reason isumask

[[Email protected]]# vim/etc/profile

1. Assume thatThe Umask value is:022 (all bits are even)666-022 =644//The starting permission value of the file2. Assume thatThe Umask value is:045 (other user group bits are odd)666-043 {621//Calculation of permissions. BecauseThe last digit of Umask is5, so in other user groups, add1.622//Real file permissions3. Default Directory Permissions calculation method777-02 2 = 7 5 5 umask 044//umask all bits are all even when example: mkdir d044 Catalog 733 Example: Touch f044//File 622umask 023//umask some or all bits of the value are odd when example: mkdir d023//directory 754 Example: Touch f023//File 644 Umask 035//umask all bits of the value are odd when example: 742 Example: Touch f035//File 642     

Umask of Linux system default permissions