DCMD_CHR_ISATTY
QNX SDP8.0Devctl and Ioctl CommandsDeveloper
Test to see if a file descriptor is associated with a terminal
Synopsis:
#include <sys/dcmd_chr.h>
#define DCMD_CHR_ISATTY __DION(_DCMD_CHR, 24)
Arguments to devctl():
Argument | Value |
---|---|
filedes | A file descriptor that you obtained by opening the device. |
dcmd | DCMD_CHR_ISATTY |
dev_data_ptr | NULL |
n_bytes | 0 |
dev_info_ptr | NULL |
Description:
This command tests to see if a file descriptor is associated with a terminal, returning EOK if it is, or ENOTTY if it isn't.
Note:
This command is for internal use, and you shouldn't use it directly.
Instead use the
isatty()
cover function.
Input:
None.
Output:
None.
Errors:
The devctl() function can return the following, in addition to the error codes listed in its entry in the C Library Reference:
- ENOTTY
- The file descriptor isn't associated with a terminal.
See also:
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