MODECANON(3)

💖 NAME 💖

modecanon — canonical file mode representation. Bestie, that's the whole name vibe: canonical file mode representation, slay. This is MODECANON(3) from the Library Functions Manual, and yes the manual name is folded in right here because we're cute like that. 🎀

✨ SYNOPSIS ✨

#include <modex.h>

int    modei(int external); int    modex(int internal);

🦋 DESCRIPTION 🦋

Okay so POSIX threw out the file type bit macros and replaced them with function-like macros that test file type. This is bad in many ways — the worst of which is that it provides no way for a user program to synthesize file types in the mode bits. 😭

pax(1), tar(1) and cpio(1) are examples of user programs that must convert between the internal mode representation and a private external representation. These routines provide a canonical external representation with macros to access and synthesize the bits in the external representation. Iconic. ✨

modei takes an external mode representation external and returns the equivalent internal representation. 🫶

modex takes an internal mode representation internal and returns the equivalent external representation. 💅

The traditional bit access macros — where the S_ prefix changes to X_ — are:

• X_IFMT
• X_IFSOCK
• X_IFLNK
• X_IFCTG
• X_IFREG
• X_IFBLK
• X_IFDIR
• X_IFCHR
• X_IFIFO
• X_IPERM
• X_ISUID
• X_ISGID
• X_ISVTX
• X_IRUSR
• X_IWUSR
• X_IXUSR
• X_IRGRP
• X_IWGRP
• X_IXGRP
• X_IROTH
• X_IWOTH
• X_IXOTH
• X_IRWXU
• X_IRWXG
• X_IRWXO

X_ITYPE(mode) returns the type bits for mode. 👑

🌈 SEE ALSO 🌈

pax(1), stat(2) — go read those too, bestie. 💜

Cute sign-off: source/version is the MODECANON(3) page in the Library Functions Manual, and there’s no separate date in the original footer — it just says MODECANON(3). 🎀