hackerbase/src/util-io.scm

127 lines
3.5 KiB
Scheme

;;
;; util-io.scm
;;
;; Special IO extensions to deal with weird stuff.
;;
;; ISC License
;;
;; Copyright 2023 Brmlab, z.s.
;; Dominik Pantůček <dominik.pantucek@trustica.cz>
;;
;; Permission to use, copy, modify, and/or distribute this software
;; for any purpose with or without fee is hereby granted, provided
;; that the above copyright notice and this permission notice appear
;; in all copies.
;;
;; THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
;; WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
;; WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
;; AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
;; CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
;; OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
;; NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
;; CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
;;
(declare (unit util-io))
(import duck)
(module*
util-io
#:doc ("Module implementing advanced I/O.")
(
read-lines/no-bom
get-process-output-lines
get-process-exit+output-lines
process-send/recv
)
(import scheme
(chicken base)
(chicken io)
(chicken process)
(chicken format))
;; If given string begins with UTF-8 BOM, it is removed.
(define (remove-optional-bom str)
(if (< (string-length str) 3)
str
(let ((maybe-bom (substring str 0 3)))
(if (string=? maybe-bom "\xEF\xBB\xBF")
(substring str 3)
str))))
(define/doc (read-lines/no-bom ip)
("
* ```port``` - an input port
Reads lines using ```read-lines``` and if the first line contains
UTF-8 BOM, removes it.
")
(let ((lines (read-lines ip)))
(if (null? lines)
lines
(cons (remove-optional-bom (car lines))
(cdr lines)))))
(define/doc (get-process-output-lines cmd . args)
("
* ```cmd``` - a string with the command
* ```args``` - list of arguments to pass to process
Returns a list of strings representing all the lines produced by
running the command given.
")
(let-values (((stdout stdin pid stderr)
(process* cmd
(map (lambda (x)
(format "~A" x))
args))))
(close-output-port stdin)
(let ((result (read-lines stdout)))
(let-values (((pid exit-ok? exit/signal) (process-wait pid)))
result))))
(define/doc (get-process-exit+output-lines cmd . args)
("
* ```cmd``` - a string with the command
* ```args``` - list of arguments to pass to process
Returns two values - an exit code and a list of strings representing
all the lines produced by running the command given.
")
(let-values (((stdout stdin pid stderr)
(process* cmd
(map (lambda (x)
(format "~A" x))
args))))
(close-output-port stdin)
(let ((result (read-lines stdout)))
(let-values (((pid exit-ok? exit/signal) (process-wait pid)))
(values exit/signal result)))))
(define/doc (process-send/recv cmd args . lines)
("
* ```cmd``` - a string with command
* ```args``` - list of arguments
* ```lines``` - lines to feed to stdin of the process
Executes given command ```cmd``` with given argument list ```args```
writing all ```lines``` to its standard input and then reads all the
process output.
")
(let-values (((stdout stdin pid stderr) (process* cmd args)))
(let loop ((lines lines))
(when (not (null? lines))
(display (car lines) stdin)
(newline stdin)
(loop (cdr lines))))
(close-output-port stdin)
(let ((result (read-lines stdout)))
(let-values (((pid exit-ok? exit/signal) (process-wait pid)))
(close-input-port stdout)
(close-input-port stderr)
result))))
)