Sha256: ca6c73cc9c055379a218b9c9c68bcb7821502095bbc5f7c9e1e2a082e1169ded
Contents?: true
Size: 966 Bytes
Versions: 180
Compression:
Stored size: 966 Bytes
Contents
#lang racket
(provide grep-file)
(define (grep-file f pattern)
(with-input-from-file f
(lambda ()
(for/list ([line (in-lines)] ;; Iterate over lines in file, lazily
[line-number (in-naturals 1)] ;; Iterate over natural numbers, lazily
#:when (regexp-match? pattern line))
(cons line-number line)))))
;; =============================================================================
;; Code inside the "main" module is run in Dr.Racket or on the command-line,
;; but not when the file is included as a library.
(module+ main
(require racket/cmdline)
(command-line
#:program "racket-grep"
#:args (pat-str . file*)
(begin
(define pattern (regexp pat-str))
(for ([f (in-list file*)])
(for ([num+str (in-list (grep-file f pattern))])
(printf "~a\n~a\n" f (make-string (string-length f) #\-))
(printf "~a : ~a\n" (car num+str) (cdr num+str))
(newline))))))
Version data entries
180 entries across 180 versions & 1 rubygems