HUMANIZE_NUMBER(9)

💖 NAME 💖

okay bestie, welcome to HUMANIZE_NUMBER(9), straight out of the Kernel Developer’s Manual — this one is all about humanize_number and format_bytes, aka human readable numbers ✨. yes, the glow-up for numbers so they don’t look like a cursed wall of digits 💅.

✨ SYNOPSIS ✨

int
humanize_number(char *buf, size_t len, uint64_t number,
    const char *suffix, int divisor);

int
format_bytes(char *buf, size_t len, uint64_t number);

🦋 DESCRIPTION 🦋

so humanize_number() takes the unsigned 64-bit quantity in number and formats it into buf 🫶. then it appends a space and then suffix to the end. the supplied buf must be at least len bytes long — no cap, that part matters 😌.

if the formatted number (including suffix) is too long to fit into buf, humanize_number() divides number by divisor until it will fit 🔁. in this case, suffix is prefixed with the appropriate SI designator. suitable values of divisor are 1024 or 1000 to remain consistent with the common meanings of the SI designator prefixes 🌈.

the prefixes are:

• k — kilo, multiplier 1024
• M — mega, multiplier 1048576
• G — giga, multiplier 1073741824
• T — tera, multiplier 1099511627776
• P — peta, multiplier 1125899906842624
• E — exa, multiplier 1152921504606846976

bestie, do not skip this one 🙈: the len argument must be at least 4 plus the length of suffix, in order to ensure a useful result in buf. it’s giving “hard requirement,” because it is 💀.

the format_bytes() function is a front-end to humanize_number() 💖. it calls the latter with a suffix of B. also, if the suffix in the returned buf would not have a prefix, the suffix is removed. this means that a result of 100000 occurs, instead of 100000 B 🎀.

🌸 RETURN VALUES 🌸

both functions return the number of characters stored in buf (excluding the terminating NUL) upon success, or -1 upon failure 😭. slay when it works, -1 when it doesn’t 💅.

🎀 SEE ALSO 🎀

• humanize_number(3)

⭐ HISTORY ⭐

these functions first appeared in NetBSD 1.5 👑.

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mwah 💋 that’s the whole page — brought to you by Debian, dated August 7, 2010, and signed HUMANIZE_NUMBER(9). periodt. 💖