getseuserbyname(3)

💅 getseuserbyname(3) — the SELinux API doc page, bestie edition

okay so you're poking around in selinux land and you found getseuserbyname?? slay, let's get you fluent. this is a page from the SELinux API documentation, and it's literally the glow-up translator between your regular Linux username and your SELinux username + level. no cap. 🦋

✨ NAME ✨

getseuserbyname — get the SELinux username and level for a given Linux username 👑

🌸 SYNOPSIS 🌸

#include <selinux/selinux.h>

int getseuserbyname(const char *linuxuser, char **selinuxuser, char **level);

that's it, that's the whole vibe. one function, three args, main character energy. 💖

🎀 DESCRIPTION 🎀

okay so getseuserbyname() goes and fetches the SELinux username and the security level that are associated with a given Linux username. like, you hand it a normal login name and it hands you back the SELinux-flavoured identity that goes with it. so iconic of it. ✨

and the tea is: once you have that SELinux username and security level, you can pass them along to other libselinux functions — the page literally name-drops get_ordered_context_list_with_level(3) and get_default_context_with_level(3) as the besties you'd send them to. 🫶

real talk though — the returned SELinux username and level should be freed by the caller using free. not me letting you leak memory, bestie, please free them. 💀

💖 RETURN VALUE 💖

• on the slay path: 0 is returned. periodt.
• on the not-slay path: -1 is returned, and errno is set appropriately. 👀

also, the errors documented for the stat(2) system call are applicable here too — so if you know your stat(2) errno lore, it transfers. iykyk. 🌈

👑 SEE ALSO 👑

• selinux(8)

🧚 cute sign-off 🧚

this lil gem was written by dwalsh@redhat.com and dated 29 September 2005 — yeah it's been serving SELinux realness since 2005 and it still ate. 💅✨ take care of those free calls and you're golden, bestie. 🎀🦋💜