The command ls stands for "LiSt"
In computing, ls is a command to list computer 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.
The command is also available in the EFI shell. In other environments, such as DOS and Microsoft Windows, similar functionality is provided by the dir command.
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. 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:
  • -l long format, displaying Unix file types, permissions, number of hard links, owner, group, size, last-modified date and filename.
  • -f do not short. Useful for directories containing large numbers of files.
  • -F appends a character revealing the nature of a file, for example, * for an executable, or / for a directory. Regular files have no suffix.
  • -a lists all files in the given directory, including those whose names start with "." (which are hidden files in Unix). By default, these files are excluded from the list.
  • -R recursively lists subdirectories. The command ls -R / would therefore list all files.
  • -d shows information about a symbolic link or directory, rather than about the link's target or listing the contents of a directory.
  • -t sort the list of files by modification time.
  • -h print sizes in human readable format. (e.g., 1K, 234M, 2G, etc.).