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	Index: head/lib/libc/stdio/fgetln.3
	===================================================================
	--- head/lib/libc/stdio/fgetln.3
	+++ head/lib/libc/stdio/fgetln.3
	@@ -28,7 +28,7 @@
	.\" @(#)fgetln.3 8.3 (Berkeley) 4/19/94
	.\" $FreeBSD$
	.\"
	-.Dd February 15, 2016
	+.Dd June 11, 2020
	.Dt FGETLN 3
	.Os
	.Sh NAME
	@@ -126,3 +126,33 @@
	.Fn fgetln
	function first appeared in
	.Bx 4.4 .
	+.Sh CAVEATS
	+Since the returned buffer is not a C string (it is not NUL terminated), a
	+common practice is to replace the newline character with
	+.Sq \e0 .
	+However, if the last line in a file does not contain a newline,
	+the returned text won't contain a newline either.
	+The following code demonstrates how to deal with this problem by allocating a
	+temporary buffer:
	+.Bd -literal
	+ char buf, lbuf;
	+ size_t len;
	+
	+ lbuf = NULL;
	+ while ((buf = fgetln(fp, &len)) != NULL) {
	+ if (buf[len - 1] == '\en')
	+ buf[len - 1] = '\e0';
	+ else {
	+ /* EOF without EOL, copy and add the NUL */
	+ if ((lbuf = malloc(len + 1)) == NULL)
	+ err(1, NULL);
	+ memcpy(lbuf, buf, len);
	+ lbuf[len] = '\e0';
	+ buf = lbuf;
	+ }
	+ printf("%s\en", buf);
	+ }
	+ free(lbuf);
	+ if (ferror(fp))
	+ err(1, "fgetln");
	+.Ed