arglist.c

#include <stdio.h>

int
main(int argc, char* argv[]) {
  int n;
  for (n = 0; n < argc; n++) {
    printf("%s\n", argv[n]);
  }
  return 0;
}

mysystem.vim

function! s:system(...)
  let cmd = ''
  for a in a:000
    if len(cmd) | let cmd .= ' ' | endif
    if a =~ '\s'
      if len(split(a, '"', 1)) % 2 == 0
        let a = '^"'.substitute(a, '"', '"""', 'g').'"'
      else
        let a = '"'.substitute(a, '"', '"""', 'g').'"'
      endif
    else
      let a = substitute(a, '"', '""""', 'g')
    endif
    let a = substitute(a, "'", "''", 'g')
    let cmd .= a
  endfor
  return system(cmd)
endfunction

function! s:test(...)
  let ret = call('s:system', a:000)
  let arr = split(ret, "\n", 1)[:-2]
  echo (string(arr[1:]) ==# string(a:000[1:]) ? "OK" : "NG") . ": " . string(arr)
endfunction

call s:test('arglist', '-"foo"', "bar")
call s:test('arglist', '-foo', "bar")
call s:test('arglist', '-f oo', "bar")
call s:test('arglist', '-f "oo', "bar")
call s:test('arglist', '-f ""oo', "bar")
call s:test('arglist', '-f """oo', "bar")
call s:test('arglist', '"-f """oo', "bar")
call s:test('arglist', '"-f """oo"', "bar")
call s:test('arglist', 'bar', '-"foo"', "bar")
call s:test('arglist', 'b ar', '-foo', "bar")
call s:test('arglist', 'ba r', '-f oo', "bar")
call s:test('arglist', 'b a r', '-f "oo', "bar")
call s:test('arglist', 'bar', '-f ""oo', "bar")
call s:test('arglist', ' bar', '-f """oo', "bar")
call s:test('arglist', 'bar ', '"-f """oo', "bar")
call s:test('arglist', ' b a r ', '"-f """oo"', "bar")
call s:test('arglist', ' "b a r" ', '"-f """oo"', "bar")
call s:test('arglist', ' "b "a" r" ', '"-f """oo"', "bar")