c4f2d992 |
1 | /* -*-c-*- |
2 | * |
03f996bd |
3 | * $Id: lexer.l,v 1.2 1997/08/04 10:24:23 mdw Exp $ |
c4f2d992 |
4 | * |
5 | * Lexical analyser for `become.conf' files |
6 | * |
7 | * (c) 1997 EBI |
8 | */ |
9 | |
03f996bd |
10 | /*----- Licensing notice --------------------------------------------------* |
c4f2d992 |
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 |
03f996bd |
25 | * along with `become'; if not, write to the Free Software Foundation, |
26 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
c4f2d992 |
27 | */ |
28 | |
29 | /*----- Revision history --------------------------------------------------* |
30 | * |
31 | * $Log: lexer.l,v $ |
03f996bd |
32 | * Revision 1.2 1997/08/04 10:24:23 mdw |
33 | * Sources placed under CVS control. |
34 | * |
35 | * Revision 1.1 1997/07/21 13:47:48 mdw |
c4f2d992 |
36 | * Initial revision |
37 | * |
38 | */ |
39 | |
40 | /*----- Declarations section ----------------------------------------------*/ |
41 | |
42 | /* --- Header files --- */ |
43 | |
44 | %{ |
45 | #include <stdio.h> |
46 | #include <stdlib.h> |
47 | #include <string.h> |
48 | |
49 | #include "become.h" |
50 | #include "lexer.h" |
51 | #include "parser.h" |
52 | #include "utils.h" |
53 | %} |
54 | |
55 | /* --- Start conditions --- */ |
56 | |
57 | %x s_KEYWORD |
58 | %x s_NORMAL |
59 | %x s_STRING |
60 | |
61 | /* --- A handy static buffer --- */ |
62 | |
63 | static char lex__buff[4096]; |
64 | static char *lex__ptr; |
65 | |
66 | /* --- Line number --- */ |
67 | |
68 | int lex_line; |
69 | |
70 | %% |
71 | |
72 | /*---- Main scanner definition -------------------------------------------*/ |
73 | |
74 | /* --- Comments --- */ |
75 | |
76 | <INITIAL,s_KEYWORD,s_NORMAL>{ |
77 | "#".*\n lex_line++; |
78 | |
79 | /* --- Whitespace --- */ |
80 | |
81 | [ \t] /* munch */ |
82 | \n lex_line++; |
83 | } |
84 | |
85 | /* --- Keywords --- */ |
86 | |
87 | <INITIAL,s_KEYWORD>{ |
88 | user BEGIN(s_NORMAL); return (USER); |
89 | command BEGIN(s_NORMAL); return (COMMAND); |
90 | host BEGIN(s_NORMAL); return (HOST); |
91 | allow BEGIN(s_NORMAL); return (ALLOW); |
92 | port BEGIN(s_NORMAL); return (PORT); |
93 | keyfile BEGIN(s_NORMAL); return (KEYFILE); |
94 | . BEGIN(s_NORMAL); return (BADTOKEN); |
95 | } |
96 | /* --- Other sorts of tokens --- */ |
97 | |
98 | <s_NORMAL>{ |
99 | [0-9]* yylval.i = atoi(yytext); return (INT); |
100 | [a-zA-Z_][a-zA-Z_0-9]* yylval.s = yytext; return (WORD); |
101 | \" BEGIN(s_STRING); lex__ptr = lex__buff; |
102 | ";" BEGIN(s_KEYWORD); return (';'); |
103 | "->" return (ARROW); |
104 | . return (yytext[0]); |
105 | } |
106 | |
107 | /* --- Strings and things --- * |
108 | * |
109 | * Be a little careful about buffer overflows here. |
110 | */ |
111 | |
112 | <s_STRING>{ |
113 | \\. { |
114 | if (lex__ptr > |
115 | lex__buff + sizeof(lex__buff) - 8) { |
116 | moan("string too long at line %i", |
117 | lex_line); |
118 | *lex__ptr++ = 0; |
119 | yylval.s = lex__buff; |
120 | BEGIN(s_NORMAL); |
121 | return (STRING); |
122 | } |
123 | *lex__ptr++ = yytext[1]; |
124 | } |
125 | \" { |
126 | *lex__ptr++ = 0; |
127 | yylval.s = lex__buff; |
128 | BEGIN(s_NORMAL); |
129 | return (STRING); |
130 | } |
131 | \n | |
132 | <<EOF>> { |
133 | moan("missing `\"', inserted at line %i", |
134 | lex_line); |
135 | lex_line++; |
136 | *lex__ptr++ = 0; |
137 | yylval.s = lex__buff; |
138 | BEGIN(s_NORMAL); |
139 | return (STRING); |
140 | } |
141 | . { |
142 | if (lex__ptr > |
143 | lex__buff + sizeof(lex__buff) - 8) { |
144 | moan("string too long at line %i", |
145 | lex_line); |
146 | *lex__ptr++ = 0; |
147 | yylval.s = lex__buff; |
148 | BEGIN(s_NORMAL); |
149 | return (STRING); |
150 | } |
151 | *lex__ptr++ = yytext[0]; |
152 | } |
153 | } |
154 | |
155 | %% |
156 | |
157 | /*----- Support routines --------------------------------------------------*/ |
158 | |
159 | /* --- @lexer_scan@ --- * |
160 | * |
161 | * Arguments: @FILE *fp@ = pointer to a stream object to scan |
162 | * |
163 | * Returns: --- |
164 | * |
165 | * Use: Initialises the scanner ready to parse from the given |
166 | * stream. |
167 | */ |
168 | |
169 | void lexer_scan(FILE *fp) |
170 | { |
171 | yyin = fp; |
172 | lex_line = 1; |
173 | BEGIN(INITIAL); |
174 | } |
175 | |
176 | /*----- That's all, folks -------------------------------------------------*/ |