 |
Index for
Section 7 |
|
 |
Alphabetical
listing for E |
|
 |
Bottom of
page |
|
eucioctl(7)
NAME
eucioctl - Interface to EUC-handling modules and drivers
SYNOPSIS
#include <sys/ioctl.h>
#include <sys/eucioctl.h>
#include <sys/stropts.h>
ioctl(
int fd,
const I_STR,
struct strioctl *argp );
PARAMETERS
fd Specifies a valid file descriptor.
argp
Points to a strioctl structure.
DESCRIPTION
The eucioctl interface is used with STREAMS modules and drivers for tty and
pty devices that handle Extended UNIX Code (EUC) code sets. This interface
consists of ioctl commands, which control character classification and
conversion related to EUC character processing.
Users issue the EUC ioctl commands to modules and drivers by calling the
STREAMS I_STR ioctl() function. (Refer to the streamio(7) reference page
for details on the use of the STREAMS I_STR ioctl() function.)
The I_STR ioctl() function takes an argument argp that is a pointer to a
strioctl structure. The members of this structure, as defined in the
/sys/stropts.h header file, are as follows:
struct strioctl(
int ic_cmd,
int ic_timout,
int ic_len,
char *ic_dp );
The EUC ioctl commands are specified by placing one of the following values
into the ic_cmd field of the strioctl structure. The use of the pointer
field, ic_dp, depends on the command.
The following commands are used to specify or retrieve the character width
information associated with the different classes of EUC code sets handled
in the local environment:
EUC_WSET
Sets the values for the byte widths and display widths of the classes
of EUC code set in the ldterm line discipline module's local
definition. The line discipline will use these values for its
subsequent operations.
EUC_WGET
Gets the current settings of the byte widths and display widths of the
classes of EUC code sets in the ldterm module's local definition.
For the EUC_SET and EUC_GET commands, the ic_dp pointer is a pointer to an
eucioc data structure, as defined in the eucioctl.h header file:
struct eucioc(
unsigned char eucw[4],
unsigned char scrw[4] );
The first parameter definition is the byte width of character sets; the
second is the display width of character sets.
The ic_len field contains the size of the eucioc structure.
When using the EUC_WSET command, the user process stores character width
values in the eucioc structure, then calls the I_STR ioctl() function to
set the values for the specified file descriptor, which must be a tty or
pty device.
When issued by the user process, the EUC_WGET command gets the values
currently in use for the specified file descriptor and stores them in the
eucioc structure.
The remaining EUC ioctl commands control character code conversion as
performed by the STREAMS modules and drivers comprising a tty or pty device
stream:
EUC_IXLON
If the module or driver previously saved its state and turned off input
conversion, this command reenables input conversion.
EUC_IXLOFF
If the module or driver is performing input conversion, then the
conversion is disabled and the mode is saved. When the EUC_IXLOFF
command is used with ICANON off, it creates a behavior roughly
equivalent to raw mode.
EUC_OXLON
Turns output conversion back on if previously disabled by EUC_OXLOFF.
EUC_OXLOFF
Disables output conversion and saves the current mode status.
EUC_MSAVE
This command is only recognized by modules and drivers that are not
operating in ASCII mode. Saves the current mode status and disables
input and output conversion.
EUC_MREST
Restores the mode previously saved by EUC_MSAVE, restoring the saved
mode and clearing the saved state flag.
None of the preceding commands use the ic_dp pointer.
The ldterm line discipline module provided by Tru64 UNIX uses EUC encoding
as its internal character representation. This means that the module will
only recognize data encoded in EUC. If an application or the terminal
hardware sends character codes in other than the EUC format, these codes
must be translated into EUC before reaching the ldterm module. Once the
module finishes processing the codes, the codes must be translated back
into the format that the application or terminal hardware handles.
If an application or the terminal hardware uses a code other than EUC and
does not perform code translation, a code conversion module must be used to
convert incoming data from its external representation into EUC and to
convert outgoing data from EUC into the appropriate external
representation. This kind of module is known as an upper converter when it
is positioned between the stream head and ldterm module in the device
stream, and a lower converter when it is positioned between the ldterm
module and device driver in the device stream.
RETURN VALUES
If an error occurs, a value of -1 is returned, and errno is set to indicate
the error.
ERRORS
If any of the following conditions occurs, the EUC ioctl commands set errno
to the corresponding value:
[EBADF]
The fd parameter is not a valid file descriptor.
[ENOTTY]
The fd parameter is not a terminal device.
[EINVAL]
The command or argp parameter is not valid, or the terminal is not a
STREAMS-based device.
[EFAULT]
The argp parameter or ic_dp field points to memory that is not part of
the process's address space.
[EPROTO]
The struct eucioc argument is invalid.
[ETIME]
Processing of the command timed out.
EXAMPLES
In the following coding example, the application gets the current settings
of the EUC character widths, then changes the settings for code set class 2
to 2 and 4 bytes for the encoding and display widths, respectively:
#include <sys/ioctl.h>
#include <sys/stropts.h>
#include <sys/eucioctl.h>
main()
{
struct eucioc euc, *eucp = &euc;
struct strioctl i_str;
bzero((caddr_t) eucp, sizeof(struct eucioc));
i_str.ic_cmd = EUC_WGET;
i_str.ic_timout = 0;
i_str.ic_len = sizeof(struct eucioc);
i_str.ic_dp = (char *)eucp;
if (ioctl(0, I_STR, &i_str) < 0) {
perror("ioctl");
exit(1);
}
i_str.ic_cmd = EUC_WSET;
eucp->eucw[2] = 2;
eucp->scrw[2] = 4;
if (ioctl(0, I_STR, &i_str) < 0) {
perror("ioctl");
exit(1);
}
}
FILES
/sys/eucioctl.h
Contains definitions for EUC-related ioctl calls.
/sys/ioctl.h
Contains the ioctl() call prototype.
/sys/stropts.h
Contains the definitions for STREAMS ioctl functions.
SEE ALSO
Commands: eucset(1)
Interfaces: ldterm(7), streamio(7)
|
Index for
Section 7 |
|
|
Alphabetical
listing for E |
|
 |
Top of
page |
|