Re: A very simple question on SED or AWK for a GURU, possibly a lisp script or emacs batch processing of many files

[Friedrich Dominicus <frido@q-software-solutions.com>]

gnuist006@hotmail.com (gnuist006) writes:

> Here is the type of lines I have in a file:
> 
> junk  label="junk1/junk2/junk3/.../junkn/" more junk
> 
> I want to find every line that has
> 
> label="..."
> 
> pattern
> 
> and then I want to replace every / by _ inside the
> quotes.
> 
> For the purposes of continuity, I want the script to look like this:
> 
> cat file |
> sed commands |
> awk commands |
you do not nead cat for just one file. 

> 
> etc.
> 
> I do not care if it all sed or awk or in what order.
Well you posted to c.l.lisp here's a Lisp solutoin for one file. It is
left to you to expand to more files (which is not too difficult)
(defun q-2003-01-14 (in-file)
  (let ((out-file (concatenate 'string (subseq in-file 0 
                                               (position #\. in-file :from-end t)) ".out")))
    (with-open-file (out out-file :direction :output 
                         :if-does-not-exist :create
                         :if-exists :supersede)
      (clawk:for-file-lines (in-file)
        (when (clawk:match clawk:$0 "label=\"\(.*)\"")
          (let* ((submatch (aref clawk:*regs* 1))
                 (substr (subseq clawk:$0 (car submatch) (cdr submatch))))
            (replace clawk:$0 
                     (pregexp-replace* "/" substr "_")
                     :start1 (car submatch)
                     :end1 (cdr submatch))))
        (princ clawk:$0 out)
        (terpri out) 
        (values)))))
              

With this file 
junk label="junk1/junk2/junk3/junk4" other stuff
other junk label="j1/j2/j3" other stuff and much more
nothing
label="/t1/t2/t3"

I got this result
junk label="junk1_junk2_junk3_junk4" other stuff
other junk label="j1_j2_j3" other stuff and much more
nothing
label="_t1_t2_t3"

Quite nice scripting with Common Lisp IMHO :)

Regards
Friedrich