TCSETS(2const) - Linux manual page (original) (raw)
TCSETS(2const) TCSETS(2const)
NAME top
TCGETS, TCSETS, TCSETSW, TCSETSF, TCGETS2, TCSETS2, TCSETSW2,
TCSETSF2, TCGETA, TCSETA, TCSETAW, TCSETAF - get and set terminal
attributesLIBRARY top
Standard C library (_libc_, _-lc_)SYNOPSIS top
**#include <asm/termbits.h>** /* Definition of **TC*** constants */
**#include <sys/ioctl.h>**
**int ioctl(int** _fd_**, TCGETS, struct termios ***_argp_**);**
**int ioctl(int** _fd_**, TCSETS, const struct termios ***_argp_**);**
**int ioctl(int** _fd_**, TCSETSW, const struct termios ***_argp_**);**
**int ioctl(int** _fd_**, TCSETSF, const struct termios ***_argp_**);**
**int ioctl(int** _fd_**, TCGETS2, struct termios2 ***_argp_**);**
**int ioctl(int** _fd_**, TCSETS2, const struct termios2 ***_argp_**);**
**int ioctl(int** _fd_**, TCSETSW2, const struct termios2 ***_argp_**);**
**int ioctl(int** _fd_**, TCSETSF2, const struct termios2 ***_argp_**);**
**int ioctl(int** _fd_**, TCGETA, struct termio ***_argp_**);**
**int ioctl(int** _fd_**, TCSETA, const struct termio ***_argp_**);**
**int ioctl(int** _fd_**, TCSETAW, const struct termio ***_argp_**);**
**int ioctl(int** _fd_**, TCSETAF, const struct termio ***_argp_**);**
**#include <asm/termbits.h>**
**struct termios;**
**struct termios2;**
**struct termio;**DESCRIPTION top
**TCGETS** Equivalent to _tcgetattr(fd, argp)_.
Get the current serial port settings.
**TCSETS** Equivalent to _tcsetattr(fd, TCSANOW, argp)_.
Set the current serial port settings.
**TCSETSW**
Equivalent to _tcsetattr(fd, TCSADRAIN, argp)_.
Allow the output buffer to drain, and set the current
serial port settings.
**TCSETSF**
Equivalent to _tcsetattr(fd, TCSAFLUSH, argp)_.
Allow the output buffer to drain, discard pending input,
and set the current serial port settings.
The following four ioctls are just like **TCGETS**, **TCSETS**, **TCSETSW**,
**TCSETSF**, except that they take a _struct termios2 *_ instead of a
_struct termios *_. If the structure member **c_cflag** contains the
flag **BOTHER**, then the baud rate is stored in the structure members
**c_ispeed** and **c_ospeed** as integer values. These ioctls are not
supported on all architectures.
**TCGETS2**
**TCSETS2**
**TCSETSW2**
**TCSETSF2**
The following four ioctls are just like **TCGETS**, **TCSETS**, **TCSETSW**,
**TCSETSF**, except that they take a _struct termio *_ instead of a
_struct termios *_.
**TCGETA**
**TCSETA**
**TCSETAW**
**TCSETAF**RETURN VALUE top
On success, 0 is returned. On error, -1 is returned and _[errno](../man3/errno.3.html)_ is
set to indicate the error.ERRORS top
**EPERM** Insufficient permission.HISTORY top
**TCGETS2**
**TCSETS2**
**TCSETSW2**
**TCSETSF2**
Linux 2.6.20.CAVEATS top
**struct termios** from _<asm/termbits.h>_ is different and incompatible
with **struct termios** from _<termios.h>_. These ioctl calls require
**struct termios** from _<asm/termbits.h>_.EXAMPLES top
Get or set arbitrary baudrate on the serial port.
/* SPDX-License-Identifier: GPL-2.0-or-later */
#include <asm/termbits.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/ioctl.h>
#include <unistd.h>
int
main(int argc, char *argv[])
{
#if !defined BOTHER
fprintf(stderr, "BOTHER is unsupported\n");
/* Program may fallback to TCGETS/TCSETS with Bnnn constants */
exit(EXIT_FAILURE);
#else
/* Declare tio structure, its type depends on supported ioctl */
# if defined TCGETS2
struct termios2 tio;
# else
struct termios tio;
# endif
int fd, rc;
if (argc != 2 && argc != 3 && argc != 4) {
fprintf(stderr, "Usage: %s device [output [input] ]\n", argv[0]);
exit(EXIT_FAILURE);
}
fd = open(argv[1], O_RDWR | O_NONBLOCK | O_NOCTTY);
if (fd < 0) {
perror("open");
exit(EXIT_FAILURE);
}
/* Get the current serial port settings via supported ioctl */
# if defined TCGETS2
rc = ioctl(fd, TCGETS2, &tio);
# else
rc = ioctl(fd, TCGETS, &tio);
# endif
if (rc) {
perror("TCGETS");
close(fd);
exit(EXIT_FAILURE);
}
/* Change baud rate when more arguments were provided */
if (argc == 3 || argc == 4) {
/* Clear the current output baud rate and fill a new value */
tio.c_cflag &= ~CBAUD;
tio.c_cflag |= BOTHER;
tio.c_ospeed = atoi(argv[2]);
/* Clear the current input baud rate and fill a new value */
tio.c_cflag &= ~(CBAUD << IBSHIFT);
tio.c_cflag |= BOTHER << IBSHIFT;
/* When 4th argument is not provided reuse output baud rate */
tio.c_ispeed = (argc == 4) ? atoi(argv[3]) : atoi(argv[2]);
/* Set new serial port settings via supported ioctl */
# if defined TCSETS2
rc = ioctl(fd, TCSETS2, &tio);
# else
rc = ioctl(fd, TCSETS, &tio);
# endif
if (rc) {
perror("TCSETS");
close(fd);
exit(EXIT_FAILURE);
}
/* And get new values which were really configured */
# if defined TCGETS2
rc = ioctl(fd, TCGETS2, &tio);
# else
rc = ioctl(fd, TCGETS, &tio);
# endif
if (rc) {
perror("TCGETS");
close(fd);
exit(EXIT_FAILURE);
}
}
close(fd);
printf("output baud rate: %u\n", tio.c_ospeed);
printf("input baud rate: %u\n", tio.c_ispeed);
exit(EXIT_SUCCESS);
#endif
}SEE ALSO top
[ioctl(2)](../man2/ioctl.2.html), [ioctl_tty(2)](../man2/ioctl%5Ftty.2.html), [termios(3)](../man3/termios.3.html)COLOPHON top
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man-pages@man7.orgLinux man-pages 6.10 2024-07-23 TCSETS(2const)
Pages that refer to this page:ioctl_tty(2), TIOCSLCKTRMIOS(2const)