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Why is my umask 4 digits?
The umask (UNIX shorthand for “user file-creation mode mask”) is a four-digit octal number that UNIX uses to determine the file permission for newly created files. Bits that are set in the umask correspond to permissions that are not automatically assigned to newly created files.
What is a umask of 0002?
The umask number controls the default permissions of newly created files. Rather than the number specifying the permission, the umask number indicates restrictions on the file permissions. Umask values are usually 0002 or 0022 – restrict write permission by others or group and others.
How does umask work?
Umask is a C-shell built-in command which allows you to determine or specify the default access (protection) mode for new files you create. You may issue the umask command interactively at the command prompt to affect files created during the current session. More often, the umask command is placed in the .
How to determine the umask value for a file?
For example, if umask is set to 022, 22 is displayed. To determine the umask value you want to set, subtract the value of the permissions you want from 666 (for a file) or 777 (for a directory). The remainder is the value to use with the umask command.
What does the first dash in umask mean?
The first dash (” – “) means that this is a “regular” file, in other words, not a directory (or a device, or any other special kind of file). The remaining nine symbols represent the permissions: rwxr-xr–.
What’s the difference between 666 and 644 in umask?
The difference between 666 and 644 is 022, which is the value you would use as an argument to the umaskcommand. You can also determine the umaskvalue you want to set by using the following table, which shows the file and directory permissions that are created for each of the octal values of umask.
How does the mask work in umask command?
The umask masks permissions by restricting them by a certain value. Essentially, each digit of the umask is “subtracted” from the OS’s default value to arrive at the default value that you define. It’s not really subtraction; technically, the mask is negated (its bitwise compliment is taken)…