Ls

In computing, ls is a command to list files in Unix and Unix-like operating systems. ls is specified by POSIX and the Single UNIX Specification. When invoked without any arguments, ls lists the files in the current working directory.

An ls utility appeared in the original version of AT&T UNIX, the name inherited from a similar command in Multics also named 'ls' - short for the word "list".

Today, the two popular versions of ls are the one provided with the GNU coreutils package, and that released by various BSD variants. Both are free software and open source, and have only minor syntax differences.

Unix and Unix-like operating systems maintain the idea of a current working directory, that is, where one is currently positioned in the hierarchy of directories. When invoked without any arguments, ls lists the files in the current working directory - but if another directory is specified, then ls will list the files there, and in fact the user may specify any list of files and directories to be listed.

Files whose names start with "." are not listed, unless the -a flag is specified, the -A flag is specified, or the files are specified explicitly.

Without options, ls displays files in a bare format. This bare format however makes it difficult to establish the type, permissions, and size of the files. The most common options to reveal this information or change the list of files are:

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