How to access errno after using syscall?

Question

I'm using syscall stat, it returns 0/-1. When -1 is returned it means, error occurred and errno is set as it should be (source: man 2 stat).

But I want to access errno and print it, how to do that?

First of all, you're not using the `stat` syscall - but the libc wrapper for that... — Antti Haapala -- Слава Україні, Jul 20 '18 at 11:44

score 1 · Accepted Answer · answered Jul 20 '18 at 11:05

1

You can get it from errno.

Also you can print the error using strerror

answered Jul 20 '18 at 11:05

Bharath Kumar

is errno a variable? Can I just do `int er = errno;` ? – Data Chanturia Jul 20 '18 at 11:06
1

Yes. Act as if it's a "global variable" declared in `errno.h` with the type of `int`, see https://en.cppreference.com/w/c/error/errno . Sometimes it's a macro. Sometimes it's a `extern int errno;`. Depends on platform. – KamilCuk Jul 20 '18 at 11:08
Thanks! It helped! ;) – Data Chanturia Jul 20 '18 at 11:09
1

Yes, you can save the value as int. – Bharath Kumar Jul 20 '18 at 11:17

1 Answers1