These special characters may be active in either canonical or noncanonical
input mode, but their use is controlled by the flags IXON and
IXOFF (see Input Modes).
int VSTART ¶This is the subscript for the START character in the special control
character array. termios.c_cc[VSTART] holds the
character itself.
The START character is used to support the IXON and IXOFF
input modes. If IXON is set, receiving a START character resumes
suspended output; the START character itself is discarded. If
IXANY is set, receiving any character at all resumes suspended
output; the resuming character is not discarded unless it is the START
character. If IXOFF is set, the system may also transmit START
characters to the terminal.
The usual value for the START character is C-q. You may not be able to change this value—the hardware may insist on using C-q regardless of what you specify.
int VSTOP ¶This is the subscript for the STOP character in the special control
character array. termios.c_cc[VSTOP] holds the character
itself.
The STOP character is used to support the IXON and IXOFF
input modes. If IXON is set, receiving a STOP character causes
output to be suspended; the STOP character itself is discarded. If
IXOFF is set, the system may also transmit STOP characters to the
terminal, to prevent the input queue from overflowing.
The usual value for the STOP character is C-s. You may not be able to change this value—the hardware may insist on using C-s regardless of what you specify.