rawtopgm(1) on Linux
The text 411a4a5fb6c4, as Debian 11 (Bullseye), Debian 10 (Buster), Debian 9 (Stretch), Debian 8 (Jessie), Debian 7 (Wheezy), Debian 6.0 (Squeeze), Debian 5.0 (Lenny), Debian 4.0 (Etch), Debian 3.1 (Sarge), Debian 3.0 (Woody) shipped it.
convert raw grayscale bytes into a portable graymap
Flags it lists
-
-bottomfirst -
-bpp -
-bt -
-headerskip -
-littleendian -
-maxval -
-rowskip