Assembly language code to find the length of a NUL-terminated string, which I posted on http://www.int80h.org/strlen/ (one of my many web sites) back in 2000, now turned into an SVG graphic. It expects ES:EDI/RDI to point at the start of the string. At the end, the length of the string, not counting the terminating NUL, is in ECX.
String Length free icon was designed by AdamStanislav for icons Png and presented to its users.
AdamStanislav
2/7/2018