HEXDUMP(9)

📦 version 15.1, in freebsd 14.5, freebsd 15.1, nixpkgs unstable

💅 NAME

okay so bestie, this is HEXDUMP(9) — the kernel developer manual page for hexdump, and its whole thing is dumping a block of bytes to the console in hexadecimal form. ✨ literally the glow-up inspector for raw bytes.

✨ SYNOPSIS

#include <sys/systm.h>

void
hexdump(void *ptr, int length, const char *hdr, int flags);

🎀 DESCRIPTION

The hexdump() function prints an array of bytes to the console in hexadecimal form, along with the ASCII representation of those bytes, if possible. no cap, it's giving “show me the vibes of this memory.” 🌸

By default, each line of output starts with an offset count, followed by 16 hexadecimal values, followed by 16 ASCII characters. iconic formatting behavior, honestly. 🫶

  • ptr — pointer to the array of bytes to print. it does not need to be NUL-terminated, bestie. it's just bytes. raw. unfiltered. 💅
  • length — number of bytes to print.
  • hdr — pointer to a NUL-terminated character string that gets prepended to each line of output. a value of NULL implies that no header will be printed. so if you want no header energy, NULL is your girl. 🙈
  • flags — flags for controlling the formatting of the output. this is where it gets cute and specific:
    • Bits 0-7 — integer value of the number of bytes to display on each line. a value of 0 implies that the default value of 16 will be used. so 0 doesn't mean zero bytes, it means “bestie, use the default.” 💖
    • Bits 8-15 — character ASCII value to use as the separator for the hexadecimal output. a value of 0 implies that the default value of 32 (ASCII space) will be used. yes, that's the space character. slay. 🔥
    • HD_OMIT_COUNT — do not print the offset column at the beginning of each line.
    • HD_OMIT_HEX — do not print the hexadecimal values on each line.
    • HD_OMIT_CHARS — do not print the character values on each line.
lowkey important: these are flags, not suggestions. the kernel is gonna format exactly what you ask for. 👑

🌈 SEE ALSO

👑 AUTHORS

This manual page was written by Scott Long. periodt. 💜

okay bye bestie — this one's from the Debian manual, dated December 7, 2003, and it was HEXDUMP(9) the whole time 🫶💖

📦 where this page comes from