Remove lines from a file: Difference between revisions

=={{header|NewLISP}}==

<lang newlisp>

(context 'ABC)

(define (remove-lines-from-a-file filename start num)

(setf new-content "")

(setf row-counter 0)

(setf start-delete-row start)

(setf end-delete-row (+ start num -1))

(setf file-content (read-file filename))

(setf max-rows (length (parse file-content "\n" 0)))

(cond

((<= start 0)

(println "Start line must be >= 1. Value passed: " start))

((<= num 0)

(println "# of lines to remove must be >= 1. Value passed: " num))

((> start max-rows)

(println "Start line must be <= " max-rows ". Value passed: " start))

((> end-delete-row max-rows)

(println "Not so much lines available to be removed. Max " (- max-rows start-delete-row) ". Value passed: " num))

(true

(dolist (row (parse file-content "\n" 0))

(++ row-counter)

(if (or (< row-counter start-delete-row) (> row-counter end-delete-row))

(setf new-content (append new-content row "\n"))

)

)

(write-file (string filename ".NEW") new-content)

)

)

)

(context 'MAIN)

(ABC:remove-lines-from-a-file "foobar.txt" 8 3)

(exit)

</lang>