• The default creation permissions can be modified using the umask utility.
  • By default, on Linux systems, the default creation permissions are 666 for files, which gives read and write permission to user, group, and others, and to 777 for directories, which means read, write and execute permission to user, group, and others.
  • Linux does not allow a file to be created with execute permissions.

Command to view the current mask value

umask -S
  • As we have already mentioned, the default creation permissions for files are 666 and for directories 777.
  • To calculate the permission bits of the new files subtract the umask value from the default value.
  • For example, to calculate how uname 022 will affect newly created files and directories, use:
    • Files: 666 - 022 = 644. The owner can read and modify the files. Group and others can only read the files.
    • Directories: 777 - 022 = 755.The owner can cd into the directory and list read, modify, create or delete the files in the directory. Group and others can cd into the directory and list and read the files.

Leave a Comment