[become] / src / lexer.l

/* -*-c-*-
 *
 * $Id: lexer.l,v 1.1 1997/07/21 13:47:48 mdw Exp $
 *
 * Lexical analyser for `become.conf' files
 *
 * (c) 1997 EBI
 */

/*----- Licencing notice --------------------------------------------------*
 *
 * This file is part of `become'
 *
 * `Become' 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 2 of the License, or
 * (at your option) any later version.
 *
 * `Become' 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 `become'; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/*----- Revision history --------------------------------------------------*
 *
 * $Log: lexer.l,v $
 * Revision 1.1  1997/07/21 13:47:48  mdw
 * Initial revision
 *
 */

/*----- Declarations section ----------------------------------------------*/

/* --- Header files --- */

%{
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "become.h"
#include "lexer.h"
#include "parser.h"
#include "utils.h"
%}

/* --- Start conditions --- */

%x s_KEYWORD
%x s_NORMAL
%x s_STRING

/* --- A handy static buffer --- */

 static char lex__buff[4096];
 static char *lex__ptr;

/* --- Line number --- */

 int lex_line;

%%

 /*---- Main scanner definition -------------------------------------------*/

 /* --- Comments --- */

<INITIAL,s_KEYWORD,s_NORMAL>{
  "#".*\n			lex_line++;

 /* --- Whitespace --- */

  [ \t]				/* munch */
  \n				lex_line++;
}

 /* --- Keywords --- */

<INITIAL,s_KEYWORD>{
  user				BEGIN(s_NORMAL); return (USER);
  command			BEGIN(s_NORMAL); return (COMMAND);
  host				BEGIN(s_NORMAL); return (HOST);
  allow				BEGIN(s_NORMAL); return (ALLOW);
  port				BEGIN(s_NORMAL); return (PORT);
  keyfile			BEGIN(s_NORMAL); return (KEYFILE);
  .				BEGIN(s_NORMAL); return (BADTOKEN);
}
 /* --- Other sorts of tokens --- */

<s_NORMAL>{
  [0-9]*			yylval.i = atoi(yytext); return (INT);
  [a-zA-Z_][a-zA-Z_0-9]*	yylval.s = yytext; return (WORD);
  \"				BEGIN(s_STRING); lex__ptr = lex__buff;
  ";"				BEGIN(s_KEYWORD); return (';');
  "->"				return (ARROW);
  .				return (yytext[0]);
}

 /* --- Strings and things --- *
  *
  * Be a little careful about buffer overflows here.
  */

<s_STRING>{
  \\.				{
				  if (lex__ptr >
				      lex__buff + sizeof(lex__buff) - 8) {
				    moan("string too long at line %i",
					 lex_line);
				    *lex__ptr++ = 0;
				    yylval.s = lex__buff;
				    BEGIN(s_NORMAL);
				    return (STRING);
				  }
				  *lex__ptr++ = yytext[1];
				}
  \"				{
				  *lex__ptr++ = 0;
				  yylval.s = lex__buff;
				  BEGIN(s_NORMAL);
				  return (STRING);
				}
  \n				|
  <<EOF>>			{
				  moan("missing `\"', inserted at line %i",
				       lex_line);
				  lex_line++;
				  *lex__ptr++ = 0;
				  yylval.s = lex__buff;
				  BEGIN(s_NORMAL);
				  return (STRING);
				}
  .				{
				  if (lex__ptr >
				      lex__buff + sizeof(lex__buff) - 8) {
				    moan("string too long at line %i",
					 lex_line);
				    *lex__ptr++ = 0;
				    yylval.s = lex__buff;
				    BEGIN(s_NORMAL);
				    return (STRING);
				  }
				  *lex__ptr++ = yytext[0];
				}
}

%%

/*----- Support routines --------------------------------------------------*/

/* --- @lexer_scan@ --- *
 *
 * Arguments:	@FILE *fp@ = pointer to a stream object to scan
 *
 * Returns:	---
 *
 * Use:		Initialises the scanner ready to parse from the given
 *		stream.
 */

void lexer_scan(FILE *fp)
{
  yyin = fp;
  lex_line = 1;
  BEGIN(INITIAL);
}

/*----- That's all, folks -------------------------------------------------*/
Commit	Line	Data
c4f2d992	1	/* --c--
	2	*
	3	* $Id: lexer.l,v 1.1 1997/07/21 13:47:48 mdw Exp $
	4	*
	5	* Lexical analyser for `become.conf' files
	6	*
	7	* (c) 1997 EBI
	8	*/
	9
	10	/----- Licencing notice --------------------------------------------------
	11	*
	12	* This file is part of `become'
	13	*
	14	* `Become' is free software; you can redistribute it and/or modify
	15	* it under the terms of the GNU General Public License as published by
	16	* the Free Software Foundation; either version 2 of the License, or
	17	* (at your option) any later version.
	18	*
	19	* `Become' is distributed in the hope that it will be useful,
	20	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	21	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	22	* GNU General Public License for more details.
	23	*
	24	* You should have received a copy of the GNU General Public License
	25	* along with `become'; if not, write to the Free Software
	26	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	27	*/
	28
	29	/----- Revision history --------------------------------------------------
	30	*
	31	* $Log: lexer.l,v $
	32	* Revision 1.1 1997/07/21 13:47:48 mdw
	33	* Initial revision
	34	*
	35	*/
	36
	37	/----- Declarations section ----------------------------------------------/
	38
	39	/* --- Header files --- */
	40
	41	%{
	42	#include <stdio.h>
	43	#include <stdlib.h>
	44	#include <string.h>
	45
	46	#include "become.h"
	47	#include "lexer.h"
	48	#include "parser.h"
	49	#include "utils.h"
	50	%}
	51
	52	/* --- Start conditions --- */
	53
	54	%x s_KEYWORD
	55	%x s_NORMAL
	56	%x s_STRING
	57
	58	/* --- A handy static buffer --- */
	59
	60	static char lex__buff[4096];
	61	static char *lex__ptr;
	62
	63	/* --- Line number --- */
	64
65	int lex_line;
66
67	%%
68
69	/---- Main scanner definition -------------------------------------------/
70
71	/* --- Comments --- */
72
73	<INITIAL,s_KEYWORD,s_NORMAL>{
74	"#".*\n lex_line++;
75
76	/* --- Whitespace --- */
77
78	[ \t] /* munch */
79	\n lex_line++;
80	}
81
82	/* --- Keywords --- */
83
84	<INITIAL,s_KEYWORD>{
85	user BEGIN(s_NORMAL); return (USER);
86	command BEGIN(s_NORMAL); return (COMMAND);
87	host BEGIN(s_NORMAL); return (HOST);
88	allow BEGIN(s_NORMAL); return (ALLOW);
89	port BEGIN(s_NORMAL); return (PORT);
90	keyfile BEGIN(s_NORMAL); return (KEYFILE);
91	. BEGIN(s_NORMAL); return (BADTOKEN);
92	}
93	/* --- Other sorts of tokens --- */
94
95	<s_NORMAL>{
96	[0-9]* yylval.i = atoi(yytext); return (INT);
97	[a-zA-Z_][a-zA-Z_0-9]* yylval.s = yytext; return (WORD);
98	\" BEGIN(s_STRING); lex__ptr = lex__buff;
99	";" BEGIN(s_KEYWORD); return (';');
100	"->" return (ARROW);
101	. return (yytext[0]);
102	}
103
104	/* --- Strings and things --- *
105	*
106	* Be a little careful about buffer overflows here.
107	*/
108
109	<s_STRING>{
110	\\. {
111	if (lex__ptr >
112	lex__buff + sizeof(lex__buff) - 8) {
113	moan("string too long at line %i",
114	lex_line);
115	*lex__ptr++ = 0;
116	yylval.s = lex__buff;
117	BEGIN(s_NORMAL);
118	return (STRING);
119	}
120	*lex__ptr++ = yytext[1];
121	}
122	\" {
123	*lex__ptr++ = 0;
124	yylval.s = lex__buff;
125	BEGIN(s_NORMAL);
126	return (STRING);
127	}
128	\n \|
129	<<EOF>> {
130	moan("missing `\"', inserted at line %i",
131	lex_line);
132	lex_line++;
133	*lex__ptr++ = 0;
134	yylval.s = lex__buff;
135	BEGIN(s_NORMAL);
136	return (STRING);
137	}
138	. {
139	if (lex__ptr >
140	lex__buff + sizeof(lex__buff) - 8) {
141	moan("string too long at line %i",
142	lex_line);
143	*lex__ptr++ = 0;
144	yylval.s = lex__buff;
145	BEGIN(s_NORMAL);
146	return (STRING);
147	}
148	*lex__ptr++ = yytext[0];
149	}
150	}
151
152	%%
153
154	/----- Support routines --------------------------------------------------/
155
156	/* --- @lexer_scan@ --- *
157	*
158	* Arguments: @FILE *fp@ = pointer to a stream object to scan
159	*
160	* Returns: ---
161	*
162	* Use: Initialises the scanner ready to parse from the given
163	* stream.
164	*/
165
166	void lexer_scan(FILE *fp)
167	{
168	yyin = fp;
169	lex_line = 1;
170	BEGIN(INITIAL);
171	}
172
173	/----- That's all, folks -------------------------------------------------/