The ls command

To display all information on the entries in the current directory, use:

By including the F option, the character at the end of the name will indicate the type of entry as follows:

(blank)

normal file or hard link

/

directory

*

executable file

@

symbolic link

=

socket

|

FIFO / pipe

To display all of the entries in one or more directories, use:

To display the attributes of a directory itself, use the d option:

ls -ld . displays the attributes of the current directory.

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How to create a directory

mkdir newdir creates the new directory under the current directory. -p will automatically create any intermediate directories that do not already exist in dirpath.

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Searching for file names beginning with a pattern

. seaches the current directory and all directories below it. / searches all of the directories in the system. Since the shell expands wildcards, the * character must be escaped.

Searching for file names based on other criteria

-mtime searches for files based on the last modification time of the file. +days matches files that were modified more than the specified number of days ago while -days matches files that have changed within the given number of days. Likewise, -size can be used to search for files based on their size in 512-byte blocks (default) or characters (c). The combination of these two can be useful for determining what used a lot of space recently, as in the last two examples above, where -mtime -7 -size +200 or -mtime -7 -size +102400 checks for files larger than 100K created within the past week.

Executing a command on each matching file name

Include {} wherever the matching file names are to be positioned in the command. The ; must be escaped and separated from the command by a space.

For example, to list the attributes of each matched file:

To list only the files containing a particluar string:

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Creating symbolic links to existing files

filepath or pattern is the fully-qualified path to an existing file. newpath is the file name of the new link, or a directory where the link is to be placed. If multiple source files or a pattern is used, the new links will be created in the dirpath directory.

h prevents the ln command from following the target symbolic link if it already exists. From the command line, i can be used to display a prompt if the target file name already exists. In scripts, f can be used to replace the link if it already exists.

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