Topic: Check data ,Return "T" or "nil " I'm in trouble

[AIberto]

Code at #3 returns T. Is it correct?

Dear kpblc,

eg: data.txt

Code: [Select]

ABCDEF123
0
3012400
3024000

If I want  only change the value of Second row , Other values unchanged

Have a quick way ? Thanks.

You would need to read & re-write the file, e.g.:

Very Thanks , Lee . 

I think the wrong,I thought , if the value unchange, so no need rewrite . 


Lee ,Good function , (setq lin (1- lin)) good idea.

I learned a new function "foreach"  , foreach is  like DOS command " FOR" 

[ronjonp]

HINT: Look in CADR & SUBST

Thanks ,ronjonp , SUBST  is useful !

Yes it is. 

[Lee Mac]

HINT: Look in CADR & SUBST

Thanks ,ronjonp , SUBST  is useful !

Just be aware that subst will substitute ALL occurrences of the item, not just the second line.

[ronjonp]

HINT: Look in CADR & SUBST

Thanks ,ronjonp , SUBST  is useful !

Just be aware that subst will substitute ALL occurrences of the item, not just the second line.

Good to note Lee 

[AIberto]

HINT: Look in CADR & SUBST

Thanks ,ronjonp , SUBST  is useful !

Just be aware that subst will substitute ALL occurrences of the item, not just the second line.

Thanks again , Lee , I haven't test with "SUBST" , Thanks for reminding .

[Lee Mac]

e.g.:

Code - Auto/Visual Lisp: [Select]

1. _$ (subst "a" "b" '("b" "c" "d" "b" "e"))
2. ("a" "c" "d" "a" "e")

Good to note Lee 

Cheers Ron