Character Description
\ Escape character. If you want to reference a special character, you must “escape” it with a backslash first. Example: touch /tmp/filename\*
/ Directory separator, used to separate a string of directory names. Example: /usr/src/linux
. dot denotes current directory. Can also “hide” files when it is the first character in a filename.
.. 2 dots denote parent directory
~ User’s home directory
* Represents 0 or more characters in a filename, or by itself, all files in a directory. Example: pic*2002 can represent the files pic2002, picJanuary2002, picFeb292002, etc.
? Represents a single character in a filename. Example: hello?.txt can represent hello1.txt and helloz.txt but not hello22.txt
[ ] Can be used to represent a range of values. Example: hello[0-2].txt represents the names hello0.txt, hello1.txt and hello2.txt
| Pipe. Redirect the output of one command into another command. Example: ls | more
> Redirect output of a command into a new file. If the file already exists, over-write it. Example: ls > myfiles.txt
>> Redirect the output of a command onto the end of an existing file. Example: echo .Mary 555-1234. >> phonenumbers.txt
< Redirect a file as input to a program. Example: more < phonenumbers.txt
; Command separator. Allows you to execute multiple commands on a single line. Example: cd /var/log ; less messages
&& Command separator as above, but only runs the second command if the first one finished without errors. Example: cd /var/logs && less messages
& Execute a command in the background, and immediately get your shell back. Example: find / -name core > /tmp/corefiles.txt &