Feng is a command line app for querying, presenting and extracting structured binary data, using a yaml-based template format that allows for specifying the file structure.
Usage: feng <filename>
A binary template reader and data presenter.
Arguments:
<filename>
Flags:
-h, --help Show context-sensitive help.
--template=STRING Parse file using this template.
-x, --extract Extract data streams from input file.
--out-dir=STRING Write files to this directory. Implies --extract
--offset=INT-64 Starting offset (default is 0).
--raw Show raw values
--local-time Show timestamps in local timezone (default is UTC).
--brief Show brief file information.
--tree Show parsed file structure tree.
--decimal Show offsets in decimal (default is hex).
--unmapped Print a report on unmapped bytes.
--overlapping Print a report on overlapping bytes.
--debug [Dev] Enable debug logging
--time [Dev] Measure where processing time is spent.
--cpu-profile=STRING [Dev] Create CPU profile.
--mem-profile=STRING [Dev] Create memory profile.
Binary releases can be downloaded from the Releases page.
You need golang installed on your system. Install the feng command:
go install github.com/martinlindhe/feng/cmd/feng@latest
Binary formats are specified in a template file. See TEMPLATE.md for the template format documentation.
Here's the OpenType Font table parsing:
endian: big
magic:
- offset: 0000
match: c'OTTO'
structs:
header:
ascii[4] Magic: c'OTTO'
u16 TableCount: ??
u16 SearchRange: ??
u16 EntrySelector: ??
u16 RangeShift: ??
table:
ascii[4] Tag: ??
label: self.Tag
u32 Checksum: ??
u32 Offset: ??
u32 Length: ??
offset: self.Offset
u8[self.Length] Data: ??
u8[alignment(self.Length, 4)] Padding: ??
offset: restore
layout:
- header Header
- table[Header.TableCount] TableMapping a file with the above structure would result in something like smoketest/reference/fonts/otf.
Template is from templates/fonts/otf.yml.
feng reads user templates from ~/.config/feng, or from a custom path with the --template argument.