Useful
Editing Keystrokes for shell
|
KEYSTROKE(s)
|
FUNCTIONS
|
Up
|
Move
back one command in the history list
|
Down
|
Move
forward one command in the history list
|
Left
|
Move
back one character.
|
Right
|
Move
forward one character
|
Esc
+ f
|
Move
forward one word
|
Esc
+ b
|
Move
forward one word
|
Ctrl
+ A
|
Move
to the beginning of line
|
Ctrl
+ E
|
Move
to the end of line
|
Ctrl
+ D
|
Delete
current character
|
Backspace
|
Delete
previous character
|
Esc
+ d
|
Delete
current word
|
Ctrl
+ U
|
Delete
from beginning of line
|
Esc
+ k
|
Delete
to end of line
|
Ctrl
+ Y
|
Retrieve
last item deleted
|
Esc
|
Insert
last word of previous command
|
Ctrl
+ L
|
Clear
the screen, placing the current line at the top of the screen
|
Tab
|
Attempt
to complete the current word, interpreting it as a filename,
username, variable name, hostname, or command as determined by the
context
|
Esc
+ ?
|
List
the possible completions
|
Ctrl
+ C
|
Sends
an interrupt signal to the currently executing command, which
generally responds by terminating itself
|
Ctrl
+ D
|
Sends
an end of file to the currently executing command. Use this
keystroke to terminate console input
|
Ctrl
+ Z
|
Suspends
the currently executing program
|
exit
|
Exit
from shell
|
Shell
special characters
|
CHARACTER
|
FUNCTIONS
|
#
|
Marks
the command as a comment, which the shell ignores
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;
|
Separates
commands, letting you enter several commands on a single line
|
&
|
Placed
at the end of a command, causes the command to execute as a
background process, so that a new shell prompt appears immediately
after the command is entered
|
()
|
execute
commands in subshell
|
{}
|
execute
commands in current shell
|
$var
|
Substitue
the declare variable with its value while execution of the command
|
special
characters used in filename globbing(filename metacharacters)
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METACHARACTER
|
FUNCTIONS
|
*
|
Matches
a string of zero or more characters
|
?
|
Matches
exactly one character
|
[
abc ...]
|
Matches
any of the characters specified
|
[
a - z ]
|
Matches
any character in the specified range
|
[!
abc ...]
|
Matches
any character other than those specified
|
[!
a - z ]
|
Matches
any character not in the specified range
|
~
|
The
home directory of the current user
|
~
userid
|
The
home directory of the specified user
|
~+
|
The
current working directory
|
~-
|
The
previous working directory
|
SHELL
ALIASES
|
alias
name='command' (like --> alias mv='mv -i')
|
unalias
<alias name>
|
special
scripts
|
SCRIPT
|
FUNCTIONS
|
/etc/profile
|
Executed
when the user logs in
|
~/.profile
|
Executed
when the user logs in
|
~/.bashrc
|
Executed
when BASH is launched
|
~/.bash_logout
|
Executed
when the user logs out
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Shell
evironment variables
|
VARIABLE
|
FUNCTIONS
|
USER
|
The
user's current username; may differ from the login name if the
user executes the su command
|
DISPLAY
|
The
X display to be used; for example, localhost:0
|
HOME
|
The
absolute path of the user's home directory
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HOSTNAME
|
Internet
name of the host
|
LOGNAME
|
The
user's login name
|
MAIL
|
The
absolute path of the user's mail file
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PATH
|
The
search path
|
SHELL
|
The
absolute path of the current shell
|
TERM
|
The
terminal type
|
printenv
|
Print
environment values
|
export
<variable>
|
To
make the value of a shell variable availabl e to the programs
invoked by the shell
|
Variable=
|
To
remove the value associated with shell variable, give the
variable an empty value (though it will appear in the output of
set cmd)
|
Unset
<variable>
|
To
dispense the variable from the shell
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CONTROLLING
OPERATION OF THE Shell
|
CHARACTER
|
FUNCTIONS
|
'
|
Characters
within a pair of single quotes are interpreted literally; that is,
their metacharacter meanings (if any) are ignored. Similarly, the
shell does not replace references to shell or environment
variables with the value of the referenced variable
|
“
|
Characters
within a pair of double quotes are interpreted literally; that is,
their metacharacter meanings (if any) are ignored. However, the
shell does replace references to shell or environment variables
with the value of the referenced variable
|
`
`
|
Text
within a pair of back quotes is interpreted as a command, which
the shell executes before executing the rest of the command line.
The output of the command replaces the original back-quoted text
|
\
|
The
following character is interpreted literally; that is, its
metacharacter meaning (if any) is ignored. The backslash character
has a special use as a line continuation character. When a line
ends with a backslash, the line and the following line are
considered part of a single line
|
Input/Output
Redirection and Piping (stdin,stdout,stderr)
|
REDIRECTOR
|
FUNCTIONS
|
cmd
> file
|
Redirects
standard output stream to specified file (same as cmd 1> file)
|
cmd
2> file
|
Redirects
standard error stream to specified file
|
cmd
>> file
|
Redirects
standard output stream to specified file, appending output to the
file if the file already exists
|
cmd
2>> file
|
Redirects
standard error stream to specified file, appending output to the
file if the file already exists
|
cmd
&> file
|
Redirects
standard output and error streams to the specified file
|
cmd
> file 2>&1
|
Another
way to redirect both stdout and stderr of cmd to a file
|
cmd
< file
|
Redirects
standard input stream to the specified file
|
cmd
<< text
|
Reads
standard input until a line matching text is found,
at which point end of file is posted
|
cmd
> /dev/null
|
Discard
stdout of cmd
|
cmd
2> /dev/null
|
Discard
stderr of cmd
|
cmd
&> /dev/null
|
Discard
stdout and stderr of cmd
|
{
cmd1; cmd2; } > file
|
Redirect
stdout from multiple commands to a file
|
cmd
<< EOL
line1
line2
EOL
|
Redirect
a bunch of lines to the stdin. If 'EOL' is quoted, text is treated
literally. This is called a here-document
|
cmd1
| cmd2
|
Takes
the standard input of cmd2 from the standard output of cmd1 (also
known as the pipe redirector)
|
cmd1
|& cmd2
|
Redirect
stdout and stderr of cmd1 to stdin of cmd2 (bash 4.0+ only)
|
cmd
| tee file
|
Redirect
stdout of cmd to a file and print it to screen
|
