No implementation or spec requires *n to be 0 to allocate a new buffer:
* musl checks for !*lineptr
(and sets *n=0 for later allocations)
* glibc checks for !*lineptr || !*n
(but only because it allocates early)
* NetBSD checks for !*lineptr
(and sets *n=0 for later allocations)
(but specifies *n => mlen(*lineptr) >= *n as a precondition,
to which this appears to be an exception)
* FreeBSD checks for !*lineptr and sets *n=0
(and specifies !*lineptr as sufficient)
* Lastly, POSIX.1-2017 specifies:
> If *n is non-zero, the application shall ensure that *lineptr
> either points to an object of size at least *n bytes,
> or is a null pointer.
The new wording matches POSIX, even if it arrives at the point slightly
differently
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@xxxxxxxxxxxxxxxxxx>
---
I seem to've blundered actually adding the page update in v1, sorry!
man3/getline.3 | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/man3/getline.3 b/man3/getline.3
index a32d7e770..6641ecc35 100644
--- a/man3/getline.3
+++ b/man3/getline.3
@@ -59,9 +59,7 @@ one was found.
.PP
If
.I "*lineptr"
-is set to NULL and
-.I *n
-is set 0 before the call, then
+is set to NULL before the call, then
.BR getline ()
will allocate a buffer for storing the line.
This buffer should be freed by the user program
--
2.20.1
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