libmagic

• file/file
• src/magic.h.in
• libmagic
• file.1
• 类似项目
  • go net/http#DetectContentType
    • whatwg mimesniff
  • pure go h2non/filetype
  • adrian-thurston/ragel
  • WASM npcz/magic
    • 只能 detect 文件 - 传递 path

file -b --mime-type README.md # text/plain
file -bsi /dev/nul            # application/x-empty; charset=binary

flag	demo
-i,--mime	text/plain; charset=utf-8
--mime-type	text/plain
--mime-encoding	utf-8
-z,--uncompress
-Z,--uncompress-noreport

• -P, --parameter
  • bytes=1048576 - 最多读取 1MB
  • encoding=65536 - 扫描多少 bytes
  • elf_notes=256
  • elf_phnum=2048
  • elf_shnum=32768
  • indir=50 - indirect
  • name=50
  • regex=8192

magic

• magic.4
• magic/Magdir
  • file 现有的 magic 定义
• /usr/local/share/misc/magic - 未编译
• /usr/local/share/misc/magic.mgc - 编译后