Igor Izvarin's question on parsing string

quoted_string_parser.c

// Usage:
// cc -W -Wall ~/tmp/quoted_string_parser.c
// ./a.out "  dwedewd, dede"  " 'sds ee' ,'ddd'"

#include <stdio.h>
#include <string.h>

static const char *whitespaces = " \r\n";
static const char *whitespaces_or_comma = " \r\n,";

static const char *skip_to(const char *str, const char *to) {
  return str + strcspn(str, to);
}

static const char *skip(const char *str, const char *chars) {
  return str + strspn(str, chars);
}

static int word_len(const char *begin, const char *end) {
  int len = end - begin;
  return len > 0 && (begin[0] == '\'' || begin[0] == '"') ? len + 1 : len;
}

static const char *skip_word(const char *str, const char *until) {
  char closing_quote[2] = { str[0], '\0' };
  return str[0] == '\'' || str[0] == '"' ?  // word begins with quote?
    skip_to(str + 1, closing_quote) :  // yes, skip until closing quote
    skip_to(str, until);  // no, skip until first whitespace or comma
}

static void parse(const char *str) {
  const char *a[5];

  a[0] = skip(str, whitespaces);  // First word begin
  a[1] = skip_word(a[0], whitespaces_or_comma); // First word end
  a[2] = skip_to(a[1], ","); // Points to comma
  a[3] = skip(a[2][0] == ',' ? a[2] + 1 : a[2], whitespaces); // Second word
  a[4] = skip_word(a[3], whitespaces); // Second word end

  printf("First: [%.*s] Second: [%.*s]\n",
         word_len(a[0], a[1]), a[0], word_len(a[3], a[4]), a[3]);
}

int main(int argc, char *argv[]) {
  int i;

  for (i = 1; i < argc; i++) {
    parse(argv[i]);
  }

  return 0;
}