Communities

Writing
Writing
Codidact Meta
Codidact Meta
The Great Outdoors
The Great Outdoors
Photography & Video
Photography & Video
Scientific Speculation
Scientific Speculation
Cooking
Cooking
Electrical Engineering
Electrical Engineering
Judaism
Judaism
Languages & Linguistics
Languages & Linguistics
Software Development
Software Development
Mathematics
Mathematics
Christianity
Christianity
Code Golf
Code Golf
Music
Music
Physics
Physics
Linux Systems
Linux Systems
Power Users
Power Users
Tabletop RPGs
Tabletop RPGs
Community Proposals
Community Proposals
tag:snake search within a tag
answers:0 unanswered questions
user:xxxx search by author id
score:0.5 posts with 0.5+ score
"snake oil" exact phrase
votes:4 posts with 4+ votes
created:<1w created < 1 week ago
post_type:xxxx type of post
Search help
Notifications
Mark all as read See all your notifications »
Users Search
Help Dashboard Sign In Sign Up
Q&A Code Reviews Meta
Q&A
Posts Tags Edits
Ask Question

Welcome to Software Development on Codidact!

Will you help us build our independent community of developers helping developers? We're small and trying to grow. We welcome questions about all aspects of software development, from design to code to QA and more. Got questions? Got answers? Got code you'd like someone to review? Please join us.

Comments on Which platforms return a non-null pointer on malloc(0)

Parent

Which platforms return a non-null pointer on malloc(0)

+4
−2

What is the portability of malloc(0);?

  • Which platforms return NULL without setting errno?
  • Which platforms return a non-null pointer?
  • Do any platforms have some other behavior?
c malloc
posted 3 months ago
user card
alx‭
628 reputation 16 10 91 129
History
Why does this post require attention from curators or moderators?
You might want to add some details to your flag.
Why should this post be closed?

1 comment thread

realloc(ptr, 0) (1 comment)
Post
+0
−2

The behavior of malloc(0) is implementation-defined and varies between platforms. Some platforms will return a NULL pointer, others might return a non-null pointer, but such a pointer should not be used. There's no widely known behavior outside of these.

posted 2 months ago
user card
harmony‭
37 reputation 0 3 2 0
History
Why does this post require attention from curators or moderators?
You might want to add some details to your flag.

2 comment threads

errno (1 comment)
re: "but such pointer should not be used" (2 comments)
errno
alx‭ wrote 2 months ago
copy link

Those are the two return values, but then errno can be 0 or ENOMEM. I think there are various weird combinations of return value and errno in the wild.