Standard C Library (libc.so, libc.a)
Interfaces documented on this reference page conform to industry standards as follows:
tcdrain(): XPG4, XPG4-UNIX
Refer to the standards(5) reference page for more information about industry standards and associated tags.
Specifies an open file descriptor.
The tcdrain() function waits until all output written to the object referred to by the filedes parameter has been transmitted.
A process group is sent a SIGTTOU signal if the tcdrain() function is called from one of its member processes. If the calling process is blocking or ignoring SIGTTOU signals, the process is allowed to perform the operation and no signal is sent.
[Digital] The tcdrain() function, which suspends the calling process until the request is completed, is redefined so that only the calling thread is suspended.
To wait until all output has been transmitted, enter:
rc = tcdrain(stdout);
Upon successful completion, a value of 0 (zero) is returned. Otherwise, a value of -1 is returned and errno is set to indicate the error.
The tcdrain() function sets errno to the specified values for the following conditions:
The filedes parameter does not specify a valid file descriptor. A signal interrupted the tcdrain() function. The file associated with the filedes parameter is not a terminal.
Functions: tcflow(3), tcflush(3), tcsendbreak(3)
Standards: standards(5) delim off