Function build_argv

src/env.c:365–502

Return a newly-allocated argv-like array, by parsing and splitting the input 'str'. 'extra_argc' is the number of additional elements to allocate in the array (on top of the number of args required to split 'str'). Store into *argc the number of arguments found (plus 1 for the program name). Example: int argc; char **argv = build_argv ("A=B uname -k', 3, &argc); R

   and the complexity of keeping track of the storage that may have been
   allocated via multiple calls to build_argv is not worth the hassle.  */
static char **
build_argv (char const *str, int extra_argc, int *argc)
{
  bool dq = false, sq = false;
  struct splitbuf ss;
  ss.argv = xnmalloc (extra_argc + 2, 2 * sizeof *ss.argv);
  ss.argc = 1;
  ss.half_alloc = extra_argc + 2;
  ss.extra_argc = extra_argc;
  ss.sep = true;
  ss.argv[ss.argc] = NULL;

  /* In the following loop,
     'break' causes the character 'newc' to be added to *dest,
     'continue' skips the character.  */
  while (*str)
    {
      char newc = *str; /* Default: add the next character.  */

      switch (*str)
        {
        case '\'':
          if (dq)
            break;
          sq = !sq;
          check_start_new_arg (&ss);
          ++str;
          continue;

        case '"':
          if (sq)
            break;
          dq = !dq;
          check_start_new_arg (&ss);
          ++str;
          continue;

        case ' ': case '\t': case '\n': case '\v': case '\f': case '\r':
          /* Start a new argument if outside quotes.  */
          if (sq || dq)
            break;
          ss.sep = true;
          str += strspn (str, C_ISSPACE_CHARS);
          continue;

        case '#':
          if (!ss.sep)
            break;
          goto eos; /* '#' as first char terminates the string.  */

        case '\\':
          /* Backslash inside single-quotes is not special, except \\
             and \'.  */
          if (sq && str[1] != '\\' && str[1] != '\'')
            break;

          /* Skip the backslash and examine the next character.  */
          newc = *++str;