#include "cache.h"
  #include "quote.h"
  
  /* Help to copy the thing properly quoted for the shell safety.
   * any single quote is replaced with '\'', any exclamation point
   * is replaced with '\!', and the whole thing is enclosed in a
   *
   * E.g.
   *  original     sq_quote     result
   *  name     ==> name      ==> 'name'
   *  a b      ==> a b       ==> 'a b'
   *  a'b      ==> a'\''b    ==> 'a'\''b'
   *  a!b      ==> a'\!'b    ==> 'a'\!'b'
   */
  static inline int need_bs_quote(char c)
  {
  	return (c == '\'' || c == '!');
  }
  
  static void sq_quote_buf(struct strbuf *dst, const char *src)
  {
  	char *to_free = NULL;
  
  	if (dst->buf == src)
  		to_free = strbuf_detach(dst, NULL);
  
  	strbuf_addch(dst, '\'');
  	while (*src) {
  		size_t len = strcspn(src, "'!");
  		strbuf_add(dst, src, len);
  		src += len;
  		while (need_bs_quote(*src)) {
  			strbuf_addstr(dst, "'\\");
  			strbuf_addch(dst, *src++);
  			strbuf_addch(dst, '\'');
  		}
  	}
  	strbuf_addch(dst, '\'');
  	free(to_free);
  }
  
  void sq_quote_argv(struct strbuf *dst, const char** argv, size_t maxlen)
  {
  	int i;
  
  	/* Copy into destination buffer. */
  	strbuf_grow(dst, 255);
  	for (i = 0; argv[i]; ++i) {
  		strbuf_addch(dst, ' ');
  		sq_quote_buf(dst, argv[i]);
  		if (maxlen && dst->len > maxlen)
  			die("Too many or long arguments");
  	}
  }