In
computing,
Control-V is a
control character in
ASCII code, also known as the
synchronous idle (
SYN) character. It is generated by pressing the
V key while holding down the
Ctrl key on a
computer keyboard.
In many
GUI environments, including
Microsoft Windows and most
desktop environments based on the
X Window System, and in applications such as
word processing software running in those environments, control-V can be used to
paste text from the
clipboard at the current
cursor position. Control-V was one of a handful of
keyboard sequences chosen by the program designers at
Xerox PARC to control
text editing. Presumably these particular
keystrokes were chosen because of their location on a standard
QWERTY keyboard, since the
Z (undo),
X (cut),
C (copy), and V (paste) keys are located together at the left end of the bottom row of the standard
QWERTY keyboard. The equivalent
Mac OS key combination on Apple computers is
Command-V.
IBM
Input/output devices utilizing the
bisync link protocol use the
SYN character code to signal the beginning of each data frame transmitted.
Unix interactive terminals use
Control-V to mean "the next character should be treated literally" (the mnemonic here is "v is for verbatim"). This allows a user to insert a literal
Control-C or
Control-H or similar control characters that would otherwise be handled by the terminal. This behavior was copied by text editors like
vi and Unix
shells like
bash and
tcsh, which offer text editing on the command line.