%{
/* ckaliases - verify syntax of sendmail-style alias files
   Copyright (C) 2005, 2007 Sergey Poznyakoff

   This program is free software; you can redistribute it and/or modify it
   under the terms of the GNU General Public License as published by the
   Free Software Foundation; either version 3 of the License, or (at your
   option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License along
   with this program. If not, see <http://www.gnu.org/licenses/>. */
	
#include "ckaliases.h"
#include "gram.h"	
	
static void line_begin (void);
static void line_add (char *text, size_t len);
static void line_add_unescape (char *text, size_t len);
static void line_finish (void);

struct obstack string_stk;
 
char *file_name;
int line_num;
 
%}


%x STR
IDENT [a-zA-Z0-9_\-+\./]+
WS [ \t]
SPEC [:@\\]
%%
  /* Comments */
#.*\n   { line_num++; return EOL; }
  /* White space */
^{WS}+\n { line_num++; return EOL; }
{WS}+    ;
  /* Names and emails */
:include:  return INCLUDE;
^{IDENT}  {
	  line_begin();
          line_add(yytext, yyleng);
          line_finish ();
	  return LHS; }
{IDENT}@{IDENT} {
	  line_begin();
          line_add(yytext, yyleng);
          line_finish();
	  return EMAIL; }
{IDENT} { line_begin();
          line_add(yytext, yyleng);
          line_finish();
	  return IDENT; }
  /* Quoted strings */
\"[^\\"\n]*\"   { line_begin();
                  line_add(yytext, yyleng);
                  line_finish();
                  return STRING; }
\"[^\\"\n]*\\.    { BEGIN(STR);
                   line_begin();
		   line_add_unescape(yytext + 1, yyleng - 1); }
<STR>[^\\"\n]*\\. { line_add_unescape(yytext, yyleng); }
<STR>[^\\"\n]*\" { BEGIN(INITIAL);
                   if (yyleng > 1) 
                     line_add(yytext, yyleng - 1); 
                   line_finish();
		   return STRING; }
  /* Other characters */
{SPEC}  return yytext[0];
\\\n    { line_num++; }
\n{WS}+/[^ \t\n]  { line_num++; return CONT; }
\n      { line_num++; return EOL; }
,	return yytext[0];
.       { error_at_line(0, 0, file_name, line_num, 
			 "Stray character %03o in alias file", yytext[0]);
          error_count++; }
%%

int
yywrap()
{
	fclose(yyin);
	return 1;
}

static char escape_transtab[] = "\\\\a\ab\bf\fn\nr\rt\t";

int
unescape_char(int c)
{
	char *p;
	
	for (p = escape_transtab; *p; p += 2) {
		if (*p == c)
			return p[1];
	}
	return c;
}

void
line_add(char *text, size_t len)
{
	obstack_grow(&string_stk, text, len);
}

void
line_add_unescape(char *text, size_t len)
{
	char c;
	obstack_grow(&string_stk, text, len - 2);
	c = unescape_char(text[len - 1]);
	obstack_1grow(&string_stk, c);
}

void
line_begin()
{
}

void
line_finish ()
{
	obstack_1grow(&string_stk, 0);
	yylval.string = obstack_finish(&string_stk);
}

void
openaliases(char *name)
{
	yyin = fopen (name, "r");
	if (!yyin)
		error(1, errno, "cannot open file `%s'", name);
	file_name = name;
	line_num = 0;
}

void
openaliases_prefix(char *prefix, char *name)
{
	char *fullname = NULL;
	struct stat st;
	
	if (stat(prefix, &st))
		error(1, errno, "cannot stat `%s'",  prefix);

	if (!S_ISDIR(st.st_mode)) {
		char *p = strrchr(prefix, '/');
		if (p)
			*p = 0;
		else
			prefix = ".";
	}
	asprintf(&fullname, "%s/%s", prefix, name);
	openaliases(fullname);
	free(fullname);
}

void
init_lex()
{
	obstack_init(&string_stk);
	yy_flex_debug = 0;
}

void
lex_debug(int debug)
{
	yy_flex_debug = debug;
}

void
read_include(SLIST **plist, char *name)
{
	char *p;
	char buffer[256];
	FILE *fp = fopen(name, "r");
  
	if (!fp) {
		error_at_line(0, 0, file_name, line_num,
			      "cannot open include file `%s': %s",
			      name, strerror(errno));
		error_count++;
		return;
	}

	while (p = fgets(buffer, sizeof buffer, fp)) {
		char *q;
      
		while (*p && isspace(*p))
			p++;
		if (*p == '#')
			continue;
		for (q = p + strlen(p) - 1; q > p && isspace(*q); q--)
			;
		q[1] = 0;
		if (*p) 
			slist_add(plist, strdup(p));
	}
	fclose(fp);
}