From: Gerry Ford <wade@...>
Date: 2008-02-11T17:22:49+09:00
Subject: Re: how to say # in ruby

Ben Bleything wrote:
> On Sat, Feb 09, 2008, Gerry Ford wrote:
>> Do I have it right that any line that begins with a hash that isn't #! 
>> is a comment, as well as the above?
> 
> Yup!  And technically #! is a comment as well, it's just a magical
> comment.
> 
I'm not sure that I can agree with you, Ben.


static void
load_file(fname, script)
    const char *fname;
    int script;
{
    extern VALUE rb_stdin;
    VALUE f;
    int line_start = 1;

    if (!fname) rb_load_fail(fname);
    if (strcmp(fname, "-") == 0) {
  f = rb_stdin;
    }
    else {
  FILE *fp = fopen(fname, "r");

  if (fp == NULL) {
      rb_load_fail(fname);
  }
  fclose(fp);

  f = rb_file_open(fname, "r");
#if defined DOSISH || defined __CYGWIN__
  {
      char *ext = strrchr(fname, '.');
      if (ext && strcasecmp(ext, ".exe") == 0)
    rb_io_binmode(f);
  }
#endif
    }

    if (script) {
  VALUE c = 1;    /* something not nil */
  VALUE line;
  char *p;

  if (xflag) {
      forbid_setid("-x");
      xflag = Qfalse;
      while (!NIL_P(line = rb_io_gets(f))) {
    line_start++;
    if (RSTRING(line)->len > 2
        && RSTRING(line)->ptr[0] == '#'
        && RSTRING(line)->ptr[1] == '!') {
        if ((p = strstr(RSTRING(line)->ptr, "ruby")) != 0) {
      goto start_read;
        }
    }
      }
      rb_raise(rb_eLoadError, "no Ruby script found in input");
  }

  c = rb_io_getc(f);
  if (c == INT2FIX('#')) {
      line = rb_io_gets(f);
      if (NIL_P(line)) return;
      line_start++;

      if (RSTRING(line)->len > 2 && RSTRING(line)->ptr[0] == '!') {
    if ((p = strstr(RSTRING(line)->ptr, "ruby")) == 0) {
        /* not ruby script, kick the program */
        char **argv;
        char *path;
        char *pend = RSTRING(line)->ptr + RSTRING(line)->len;

        p = RSTRING(line)->ptr + 1;  /* skip `#!' */
        if (pend[-1] == '\n') pend--; /* chomp line */
        if (pend[-1] == '\r') pend--;
        *pend = '\0';
        while (p < pend && ISSPACE(*p))
      p++;
        path = p;  /* interpreter path */
        while (p < pend && !ISSPACE(*p))
      p++;
        *p++ = '\0';
        if (p < pend) {
      argv = ALLOCA_N(char*, origargc+3);
      argv[1] = p;
      MEMCPY(argv+2, origargv+1, char*, origargc);
        }
        else {
      argv = origargv;
        }
        argv[0] = path;
        execv(path, argv);

        ruby_sourcefile = rb_source_filename(fname);
        ruby_sourceline = 1;
        rb_fatal("Can't exec %s", path);
    }

        start_read:
    p += 4;
    RSTRING(line)->ptr[RSTRING(line)->len-1] = '\0';
    if (RSTRING(line)->ptr[RSTRING(line)->len-2] == '\r')
        RSTRING(line)->ptr[RSTRING(line)->len-2] = '\0';
    if ((p = strstr(p, " -")) != 0) {
        p++;  /* skip space before `-' */
        while (*p == '-') {
      p = moreswitches(p+1);
        }
    }
      }
  }
  else if (!NIL_P(c)) {
      rb_io_ungetc(f, c);
  }
  require_libraries();  /* Why here? unnatural */
  if (NIL_P(c)) return;
    }
    rb_compile_file(fname, f, line_start);
    if (script && ruby__end__seen) {
  rb_define_global_const("DATA", f);
    }
    else if (f != rb_stdin) {
  rb_io_close(f);
    }

    if (ruby_parser_stack_on_heap()) {
        rb_gc();
    }
}

# end function load_file in ruby.c

What good's a comment if you have to say the right thing?

rb_fatal("Can't exec %s", path);
--
Gerry Ford
-- 
Posted via http://www.ruby-forum.com/.