Hidden file and hidden directory

In computing, a hidden directory or hidden file on a computer is a directory (folder) or file which a user cannot see by default. Hidden directories most often serve to hide important operating system-related files and user preferences. However, malicious programs can also use this functionality to hide their presence from unaware users.

Unix and Unix-like environments

In Unix-like operating systems there is a convention that a file or directories with a filename that starts with a period/full stop character (for example: /home/user/.config) is to be treated as hidden. How to show or hide them either depends on the file manager in use (e.g. mc shows them by default, Ctrl-h (h stands for hidden) is the keyboard shortcut to show in Nautilus) or ls with the flag -a can reveal otherwise invisible resources: (ls -a).

Additionally, wildcards on the shell command line will not match dotfiles unless they start with an explicit '.' .

A common use these dotfiles is for personal configuration settings.^[1][2][3]

Mac OS X

In addition to the "dotfile" behaviour, files with the "Invisible" attribute are hidden in Finder in Mac OS X. This is set using the SetFile command. For example, invoking SetFile -a V jimbo will hide the file "jimbo". Alternate way is to use chflags command. chflags nohidden ~/Library/ clears hidden attribute on user's Library folder on Mac OS X 10.7 while SetFile fails with an error.

GNOME

In addition to hiding "dotfiles", the Nautilus file manager also looks for a text file named .hidden in each directory and hides all files listed inside.

DOS

In MS-DOS and other DOS systems, users can make files and folders hidden or visible by toggling their Hidden File attribute using attrib command. Invoking dir /a may reveal the existence of unsuspected hidden objects.

Microsoft Windows

In Microsoft Windows, hiding resembles that of DOS — users can hide or unhide items by toggling the "Hidden" attribute, using attrib or Windows Explorer.

References

1. ^ "Configuring X: What are all those dotfiles for anyway?", redhat.com
2. ^ "Sample .bashrc and .bash_profile Files", Linux Documentation Project
3. ^ http://www.ibm.com/developerworks/linux/library/l-config/index.html

External links

• Bellevue Linux Users Group: Hidden files in Unix-like operating systems (via archive.org)
• Computer Hope: Microsoft DOS attrib command