fpurge.3bsd man page
fpurge — flush a stream
#include <stdio.h> (See libbsd(7) for include usage.)
fpurge() erases any input or output buffered in the given stream. For output streams this discards any unwritten output. For input streams this discards any input read from the underlying object but not yet obtained via getc(3); this includes any text pushed back via ungetc(3).
Upon successful completion 0 is returned. Otherwise,
EOF is returned and the global variable errno is set to indicate the error.
stream is not an open stream.
fclose(3), fopen(3), setvbuf(3)
fpurge() function first appeared in 4.4BSD-Lite.
explain(1), explain(3), explain_fpurge(3), explain_fpurge_or_die(3), stdio(3), stdio_ext(3).