If the user is unfamiliar with seeking semantics, they may sensibly
assume that seeking past the end is invalid
Reported-in: https://twitter.com/eatijr/status/1526264195808911361
Signed-off-by: Ahelenia Ziemiańska <redacted>
---
man3/fseek.3 | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/man3/fseek.3 b/man3/fseek.3
index 01bd34c5b..c19303421 100644
--- a/man3/fseek.3
+++ b/man3/fseek.3
@@ -118,6 +118,14 @@ On some non-UNIX systems, an
.I fpos_t
object may be a complex object and these routines may be the only way to
portably reposition a text stream.
+.PP
+If the stream refers to a regular file
+and the resulting stream offset is beyond the size of the file,
+subsequent writes will extend the file with a hole, up to the offset,
+before committing any data.
+See
+.BR lseek (2)
+for details on file seeking semantics.
.SH RETURN VALUE
The
.BR rewind ()
--
2.30.2