Looks for a character with the specified ASCII code in a string
(vl-string-position char-codestr [start-pos [from-end-p]])
An integer representing the displacement at which char-code was found from the beginning of the string; nil if the character was not found.
_$ (vl-string-position (ascii "z") "azbdc")
1
_$ (vl-string-position 122 "azbzc")
1
_$ (vl-string-position (ascii "x") "azbzc")
nil
The search string used in the following example contains two “z” characters. Reading from left to right, with the first character being displacement 0, there is one z at displacement 1 and another z at displacement 3:
_$ (vl-string-position (ascii "z") "azbzlmnqc")
1
Searching from left to right (the default), the “z” in position 1 is the first one vl-string-position encounters. But when searching from right to left, as in the following example, the “z” in position 3 is the first one encountered:
_$ (vl-string-position (ascii "z") "azbzlmnqc" nil t)
3