Topic: Removing Lines from Text File

[ElpanovEvgeniy]

other version...

Code: [Select]

(defun f (a b c) (and a b (write-line b c)))
(defun c:test (/  c d)
 ;; '(nil nil nil t) - Pattern of lines of the text for record
 (setq d (getfiled "Select File" "" "txt" 16)
       c (open (strcat d "-New.txt") "w")
       d (open d "r")
 ) ;_  setq
 (while (foreach a '(nil nil nil t) (f a (read-line d) c)))
 (close d)
 (close c)
) ;_  defun

[Lee Mac]

Very nice solution Evgeniy, although I think he/she wanted to keep the first line, and discard the rest (other three), so that while loop may need some re-jigging... 

But I do wish that you would give you variables some meaningful names... makes it so much easier to follow... 

[CAB]

Yes '(t nil nil nil)

[Lee Mac]

Yes '(t nil nil nil)

Not quite.

The While loop relies on the 't' being last... 

[VovKa]

But I do wish that you would give you variables some meaningful names... makes it so much easier to follow... 

i believe Evgeniy has a Kelvinator for "forum-posting" purposes

[CAB]

I better have a close look.

[CAB]

I see, very clever.
But this works.

Code: [Select]

(defun f (flag str fn) (and flag str (write-line str fn)))
(defun c:test (/ fname fnr fnw s)
 ;; '(nil nil nil t) - Pattern of lines of the text for record
 (setq fname (getfiled "Select File" "" "txt" 16)
       fnw (open (strcat fname "-New.txt") "w")
       fnr (open fname "r")
 ) ;_  setq
 (while (foreach a '(t nil nil nil) (f a (setq s (read-line fnr)) fnw) s))
 (close fnw)
 (close fnr)
) ;_  defun

[Lee Mac]

I see, very clever.
But this works.

It does indeed 

[JohnK]

<snip>
But I do wish that you would give you variables some meaningful names... makes it so much easier to follow... 

heh, Dave Stein used to use vowels. *lmao*
(defun blah ( / a e i o u ) ...

[Lee Mac]

<snip>
But I do wish that you would give you variables some meaningful names... makes it so much easier to follow... 

heh, Dave Stein used to use vowels. *lmao*
(defun blah ( / a e i o u ) ...

Haha, reminds me of an article I remember someone posting on here describing 'good programming practices', like having two variables like:

Code: [Select]

(defun blah (/ lI Il ...

And using comments that describe the code as doing something completely different...

trying to find the thread now...

[Kerry]

But I do wish that you would give you variables some meaningful names... makes it so much easier to follow... 

i believe Evgeniy has a Kelvinator for "forum-posting" purposes

 

[Lee Mac]

<snip>
But I do wish that you would give you variables some meaningful names... makes it so much easier to follow... 

heh, Dave Stein used to use vowels. *lmao*
(defun blah ( / a e i o u ) ...

Haha, reminds me of an article I remember someone posting on here describing 'good programming practices', like having two variables like:

Code: [Select]

(defun blah (/ lI Il ...

And using comments that describe the code as doing something completely different...

trying to find the thread now...

Ahh yes

[JohnK]

<snip>
Ahh yes

*click-click* Oh my goodness. yeah dont do that. just put the keyboard down and step away.

[ElpanovEvgeniy]

But I do wish that you would give you variables some meaningful names... makes it so much easier to follow... 

i believe Evgeniy has a Kelvinator for "forum-posting" purposes

I also am Kelvinator... 

It is convenient me, when local variables short, they do not prevent to see music of the program and its rhythm.
Long names of variables, can borrow more places, than sense the code.

[Mark]

Thanks CAB ... writing to a new text file helps. I just wish I knew  which part of the code to modify if I needed to keep, say every 5th line, 6th line or some other number instead of the 4th.

Is there some kind of pattern you are looking for?