7. Device- and Class- Specific Functions Manager¶

7.1. Introduction¶

The device- and class- specific functions manager is ...

The directives provided by the device- and class- specific functions manager are:

cfgetispeed - Reads terminal input baud rate
cfgetospeed - Reads terminal output baud rate
cfsetispeed - Sets terminal input baud rate
cfsetospeed - Set terminal output baud rate
tcgetattr - Gets terminal attributes
tcsetattr - Set terminal attributes
tcsendbreak - Sends a break to a terminal
tcdrain - Waits for all output to be transmitted to the terminal
tcflush - Discards terminal data
tcflow - Suspends/restarts terminal output
tcgetpgrp - Gets foreground process group ID
tcsetpgrp - Sets foreground process group ID

7.2. Background¶

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7.3. Operations¶

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7.4. Directives¶

This section details the device- and class- specific functions manager’s directives. A subsection is dedicated to each of this manager’s directives and describes the calling sequence, related constants, usage, and status codes.

7.4.1. cfgetispeed - Reads terminal input baud rate¶

CALLING SEQUENCE:

#include <termios.h>
int cfgetispeed(
    const struct termios *p
);

STATUS CODES:

The cfgetispeed() function returns a code for baud rate.

DESCRIPTION:

The cfsetispeed() function stores a code for the terminal speed stored in a struct termios. The codes are defined in <termios.h> by the macros BO, B50, B75, B110, B134, B150, B200, B300, B600, B1200, B1800, B2400, B4800, B9600, B19200, and B38400.

The cfsetispeed() function does not do anything to the hardware. It merely stores a value for use by tcsetattr().

NOTES:

Baud rates are defined by symbols, such as B110, B1200, B2400. The actual number returned for any given speed may change from system to system.

7.4.2. cfgetospeed - Reads terminal output baud rate¶

CALLING SEQUENCE:

#include <termios.h>
    int cfgetospeed(
    const struct termios *p
);

STATUS CODES:

The cfgetospeed() function returns the termios code for the baud rate.

DESCRIPTION:

The cfgetospeed() function returns a code for the terminal speed stored in a struct termios. The codes are defined in <termios.h> by the macros BO, B50, B75, B110, B134, B150, B200, B300, B600, B1200, B1800, B2400, B4800, B9600, B19200, and B38400.

The cfgetospeed() function does not do anything to the hardware. It merely returns the value stored by a previous call to tcgetattr().

NOTES:

Baud rates are defined by symbols, such as B110, B1200, B2400. The actual number returned for any given speed may change from system to system.

7.4.3. cfsetispeed - Sets terminal input baud rate¶

CALLING SEQUENCE:

#include <termios.h>
int cfsetispeed(
    struct termios *p,
    speed_t         speed
);

STATUS CODES:

The cfsetispeed() function returns a zero when successful and returns -1 when an error occurs.

DESCRIPTION:

The cfsetispeed() function stores a code for the terminal speed stored in a struct termios. The codes are defined in <termios.h> by the macros BO, B50, B75, B110, B134, B150, B200, B300, B600, B1200, B1800, B2400, B4800, B9600, B19200, and B38400.

NOTES:

This function merely stores a value in the termios structure. It does not change the terminal speed until a tcsetattr() is done. It does not detect impossible terminal speeds.

7.4.4. cfsetospeed - Sets terminal output baud rate¶

CALLING SEQUENCE:

#include <termios.h>
int cfsetospeed(
    struct termios *p,
    speed_t         speed
);

STATUS CODES:

The cfsetospeed() function returns a zero when successful and returns -1 when an error occurs.

DESCRIPTION:

The cfsetospeed() function stores a code for the terminal speed stored in a struct termios. The codes are defiined in <termios.h> by the macros BO, B50, B75, B110, B134, B150, B200, B300, B600, B1200, B1800, B2400, B4800, B9600, B19200, and B38400.

The cfsetospeed() function does not do anything to the hardware. It merely stores a value for use by tcsetattr().

NOTES:

This function merely stores a value in the termios structure. It does not change the terminal speed until a tcsetattr() is done. It does not detect impossible terminal speeds.

7.4.5. tcgetattr - Gets terminal attributes¶

CALLING SEQUENCE:

#include <termios.h>
#include <unistd.h>
int tcgetattr(
    int             fildes,
    struct termios *p
);

STATUS CODES:

`EBADF`	Invalid file descriptor
`ENOOTY`	Terminal control function attempted for a file that is not a terminal.

DESCRIPTION:

The tcgetattr() gets the parameters associated with the terminal referred to by fildes and stores them into the termios() structure pointed to by termios_p.

NOTES:

NONE

7.4.6. tcsetattr - Set terminal attributes¶

CALLING SEQUENCE:

#include <termios.h>
#include <unistd.h>
int tcsetattr(
    int                   fildes,
    int                   options,
    const struct termios *tp
);

STATUS CODES:

E The

DESCRIPTION:

NOTES:

7.4.7. tcsendbreak - Sends a break to a terminal¶

CALLING SEQUENCE:

int tcsendbreak(
    int fd
);

STATUS CODES:

E The

DESCRIPTION:

NOTES:

This routine is not currently supported by RTEMS but could be in a future version.

7.4.8. tcdrain - Waits for all output to be transmitted to the terminal.¶

CALLING SEQUENCE:

#include <termios.h>
#include <unistd.h>
int tcdrain(
    int fildes
);

STATUS CODES:

`EBADF`	Invalid file descriptor
`EINTR`	Function was interrupted by a signal
`ENOTTY`	Terminal control function attempted for a file that is not a terminal.

DESCRIPTION:

The tcdrain() function waits until all output written to fildes has been transmitted.

NOTES:

NONE

7.4.9. tcflush - Discards terminal data¶

CALLING SEQUENCE:

int tcflush(
    int fd
);

STATUS CODES:

E The

DESCRIPTION:

NOTES:

This routine is not currently supported by RTEMS but could be in a future version.

7.4.10. tcflow - Suspends/restarts terminal output.¶

CALLING SEQUENCE:

int tcflow(
    int fd
);

STATUS CODES:

E The

DESCRIPTION:

NOTES:

This routine is not currently supported by RTEMS but could be in a future version.

7.4.11. tcgetpgrp - Gets foreground process group ID¶

CALLING SEQUENCE:

int tcgetpgrp(
);

STATUS CODES:

E The

DESCRIPTION:

NOTES:

This routine is not currently supported by RTEMS but could be in a future version.

7.4.12. tcsetpgrp - Sets foreground process group ID¶

CALLING SEQUENCE:

int tcsetpgrp(
);

STATUS CODES:

E The

DESCRIPTION:

NOTES:

This routine is not currently supported by RTEMS but could be in a future version.