You can change the owner of your files with the chown command. When the -R option is specified, the chown command recursively descends through the directory structure from the specified directory. No errors are reported when the -f option is specified. The user access permissions for program.c now apply to jim . As the owner, jim can use the chmod command to permit or deny other users access to program.c.
Every file has an owner.
For new files, the user who creates the file is the owner of that file. The owner assigns an access mode to the file. Access modes grant other system users permission to read, modify, or execute the file. Only the file's owner or users with root authority can change the access mode of a file. When a new file is created, the default permissions are read, write, and execute permission for the user who created the file.