Insert character two spaces from end of text

[Anonymous]

I'm very new to AutoCAD and Lisp, but pretty experienced in Python.

I have a text string in AutoCAD, and want to insert a '+' character two spaces from the end of the text.

Ex. 'ABCDEFG' > 'ABCDE+FG', 'AB23567890J' > 'AB2356789+OJ', etc.

This is simple enough to do in Python, VB, C++, etc, but can't figure out how to do it in Lisp. I found the code 'Insert Nth' on Lee Mac's site. That code appears to be limited to always inserting the character at the same position from the start, whereas mine is the same position from the end. Conceptually this seems simple, but have no clue how to do so in Lisp. Any help? Thanks.

[Shneuph · Accepted solution]

(Setq str "this is my string")
(strcat
  (substr str 1 (- (strlen str) 1))
  "+"
  (substr str (- (strlen str) 1))
  );strcat

[devitg]

Try it , please .

No error  check, no nothing , just crude LISP

(setq string (cdr (Assoc 1 (entget (ssname(ssget "+.:S"  (list (cons 0  "text"  )))0)))))

(setq str-len (STRLEN string))

(setq pos (-  str-len 1))
;;Copyright © http://autolisp.mapcar.net/strtok.html

(DEFUN STR-INSERT  (STR NEU POS /)
  (STRCAT
    (SUBSTR STR 1 (1- POS))
    NEU
    (SUBSTR STR POS)
    )
  )

(Setq string+nn (STR-INSERT string "+" pos))

[pbejse · Accepted solution]

---

@Shneuph wrote:

...
  (substr str 1 (- (strlen str) 1))
...

---

"this is my strin+ng"  

Shouldn't that be:

(substr str 1 (- (strlen str) 2))

variant

((lambda (n)
	   (strcat
	     (substr str 1 (- n 2))
	     "+"
	     (substr str (1- n))
	   )
	 )
	  (strlen str)
	)

[Shneuph]

Yes, you are correct.  Good catch.

[Anonymous]

Thanks all, works great!

[Anonymous]

Thanks devitg, get an error though:

Bad argument type, numberp: nil

[devitg]

I'll check it. 

[Shneuph]

Looks like the extra space here:

(setq pos (-  str-len 1))

Edit:
Nope maybe that's not it.

[devitg]

Hi , as per me , LISp allow extra spaces 

(setq       pos       (-       str-len     1))

But not  a extra space as follow 

(setq       pos       (-       str  -len     1))

As it  will search for 2 variables 

str 
-len