string search...and count..?

I need a way of searching a string to "count" how many times string "a"
apears in string "b".<br>
<br>
ie:<br>
string b: "The house is a tall one also ." (the string to be
seached)<br>
string a: " " (double space)<br>
<br>
This may seem odd to some of you (or all)..<br>
But it's part of a much larger lisp.<br>
<br>
TIA.

 

Try this.

Command: (searchstring "hellolo" "lo")
2

Tim

(defun SearchString (Str1 Str2 / cnt2)

(setq slng1 (strlen Str2)
cnt2 0
)
(while (>= (strlen Str1) slng1)
(if (= Str2 (substr Str1 1 slng1))
(setq cnt2 (1+ cnt2))
)
(setq Str1 (substr Str1 2 (strlen Str1)))
)
cnt2
)

 

Here's some sample code to get you going. If the var "found" is not nil then
the pattern was found. The length of "found" will tell you haw many times it
was found. Each element of found gives the index position in the string
where it was found.

(setq str "This is a sample string")
(setq srchstr " ");double space
(setq test -1)
(while (setq test (vl-string-search srchstr str (1+ test)))
(setq found (cons test found))
)
(setq found (reverse found))

This returns: (4 10 18)

HTH,

 

I like your's better Jeff. Returns more options incase you need that info later.

Tim

 

thank you very much.