[Linux] Bash umask Uso: Controlando permisos de archivos por defecto

Overview

The umask command in Bash is used to set default file permissions for newly created files and directories. It defines the permissions that will be masked (or removed) when a new file or directory is created, ensuring that they do not have more permissions than intended.

Usage

The basic syntax of the umask command is as follows:

umask [options] [arguments]

Common Options

-S: Display the current umask value in symbolic notation.
-p: Print the current umask value in a format that can be reused in scripts.

Common Examples

Check Current umask Value To see the current umask setting, simply run:
```
umask
```
Set a New umask Value To set a umask value of 027, which allows the owner to read and write, the group to read, and no permissions for others:
```
umask 027
```
Set umask in Symbolic Notation To set the umask using symbolic notation, which is more readable:
```
umask u=rwx,g=rx,o=
```
Display umask in Symbolic Format To display the current umask in symbolic format:
```
umask -S
```
Set umask Temporarily To temporarily change the umask for a single command:
```
(umask 007; touch newfile)
```

Tips

Always check your current umask before setting a new one to avoid unintended permission issues.
Consider setting a stricter umask in shared environments to enhance security.
Remember that umask values are subtracted from the default permissions (666 for files and 777 for directories).
You can add your umask settings to your shell’s configuration file (like ~/.bashrc) to make them persistent across sessions.