MAC_TEXT(3)

okay so bestie, welcome to MAC_TEXT(3) from the Library Functions Manual — we're doing MAC label ↔ text representation today, and yes it's giving conversion core. ✨

🎀 NAME 🎀

mac_from_text, mac_to_text — convert MAC label to/from text representation

📚 LIBRARY 📚

Standard C Library (libc, -lc) — periodt.

✨ SYNOPSIS ✨

#include <sys/mac.h>

int
mac_from_text(mac_t *mac, const char *text);

int
mac_to_text(mac_t label, char **text);

💖 DESCRIPTION 💖

okay so mac_from_text() converts the text representation of a label into the internal policy label format (mac_t) and places it in *mac. and the way that *mac must later be freed with mac_free(3) is lowkey important — don't forget, bestie.

mac_to_text() allocates storage for *text, which will be set to the text representation of label and must later be freed with free(3). slay, but free it.

For the MAC label format, refer to maclabel(7). iykyk. 🦋

🔁 RETURN VALUES 🔁

The mac_from_text() and mac_to_text() functions return the value 0 if successful; otherwise the value -1 is returned and the global variable errno is set to indicate the error. slay when it's 0, 😭 when it's -1.

⚠️ COMPATIBILITY ⚠️

POSIX.1e does not define a format for text representations of MAC labels. no cap.

POSIX.1e requires that text strings allocated using mac_to_text() be freed using mac_free(3); in the FreeBSD implementation, they must be freed using free(3), as mac_free(3) is used only to free memory used for type mac_t. okay so that's the tea ☕ — don't mix those up.

💀 ERRORS 💀

• [ENOMEM] — Insufficient memory was available to allocate internal storage.

👀 SEE ALSO 👀

literally go read: free(3), mac(3), mac_get(3), mac_is_present(3), mac_prepare(3), mac_set(3), posix1e(3), mac(4), maclabel(7). the whole friend group 🫶

🌈 STANDARDS 🌈

POSIX.1e is described in IEEE POSIX.1e draft 17. iconic.

👑 HISTORY 👑

Support for Mandatory Access Control was introduced in FreeBSD 5.0 as part of the TrustedBSD Project. main character energy from day one 💅

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mwah 💋 — this page is from Debian, dated October 26, 2025, and it's literally MAC_TEXT(3).