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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: lexer.l,v 1.3 1998/01/12 16:46:07 mdw Exp $ |
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4 | * |
5 | * Lexical analyser for `become.conf' files |
6 | * |
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7 | * (c) 1998 EBI |
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8 | */ |
9 | |
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10 | /*----- Licensing notice --------------------------------------------------* |
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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 |
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25 | * along with `become'; if not, write to the Free Software Foundation, |
26 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
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27 | */ |
28 | |
29 | /*----- Revision history --------------------------------------------------* |
30 | * |
31 | * $Log: lexer.l,v $ |
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32 | * Revision 1.3 1998/01/12 16:46:07 mdw |
33 | * Fix copyright date. |
34 | * |
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35 | * Revision 1.2 1997/08/04 10:24:23 mdw |
36 | * Sources placed under CVS control. |
37 | * |
38 | * Revision 1.1 1997/07/21 13:47:48 mdw |
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39 | * Initial revision |
40 | * |
41 | */ |
42 | |
43 | /*----- Declarations section ----------------------------------------------*/ |
44 | |
45 | /* --- Header files --- */ |
46 | |
47 | %{ |
48 | #include <stdio.h> |
49 | #include <stdlib.h> |
50 | #include <string.h> |
51 | |
52 | #include "become.h" |
53 | #include "lexer.h" |
54 | #include "parser.h" |
55 | #include "utils.h" |
56 | %} |
57 | |
58 | /* --- Start conditions --- */ |
59 | |
60 | %x s_KEYWORD |
61 | %x s_NORMAL |
62 | %x s_STRING |
63 | |
64 | /* --- A handy static buffer --- */ |
65 | |
66 | static char lex__buff[4096]; |
67 | static char *lex__ptr; |
68 | |
69 | /* --- Line number --- */ |
70 | |
71 | int lex_line; |
72 | |
73 | %% |
74 | |
75 | /*---- Main scanner definition -------------------------------------------*/ |
76 | |
77 | /* --- Comments --- */ |
78 | |
79 | <INITIAL,s_KEYWORD,s_NORMAL>{ |
80 | "#".*\n lex_line++; |
81 | |
82 | /* --- Whitespace --- */ |
83 | |
84 | [ \t] /* munch */ |
85 | \n lex_line++; |
86 | } |
87 | |
88 | /* --- Keywords --- */ |
89 | |
90 | <INITIAL,s_KEYWORD>{ |
91 | user BEGIN(s_NORMAL); return (USER); |
92 | command BEGIN(s_NORMAL); return (COMMAND); |
93 | host BEGIN(s_NORMAL); return (HOST); |
94 | allow BEGIN(s_NORMAL); return (ALLOW); |
95 | port BEGIN(s_NORMAL); return (PORT); |
96 | keyfile BEGIN(s_NORMAL); return (KEYFILE); |
97 | . BEGIN(s_NORMAL); return (BADTOKEN); |
98 | } |
99 | /* --- Other sorts of tokens --- */ |
100 | |
101 | <s_NORMAL>{ |
102 | [0-9]* yylval.i = atoi(yytext); return (INT); |
103 | [a-zA-Z_][a-zA-Z_0-9]* yylval.s = yytext; return (WORD); |
104 | \" BEGIN(s_STRING); lex__ptr = lex__buff; |
105 | ";" BEGIN(s_KEYWORD); return (';'); |
106 | "->" return (ARROW); |
107 | . return (yytext[0]); |
108 | } |
109 | |
110 | /* --- Strings and things --- * |
111 | * |
112 | * Be a little careful about buffer overflows here. |
113 | */ |
114 | |
115 | <s_STRING>{ |
116 | \\. { |
117 | if (lex__ptr > |
118 | lex__buff + sizeof(lex__buff) - 8) { |
119 | moan("string too long at line %i", |
120 | lex_line); |
121 | *lex__ptr++ = 0; |
122 | yylval.s = lex__buff; |
123 | BEGIN(s_NORMAL); |
124 | return (STRING); |
125 | } |
126 | *lex__ptr++ = yytext[1]; |
127 | } |
128 | \" { |
129 | *lex__ptr++ = 0; |
130 | yylval.s = lex__buff; |
131 | BEGIN(s_NORMAL); |
132 | return (STRING); |
133 | } |
134 | \n | |
135 | <<EOF>> { |
136 | moan("missing `\"', inserted at line %i", |
137 | lex_line); |
138 | lex_line++; |
139 | *lex__ptr++ = 0; |
140 | yylval.s = lex__buff; |
141 | BEGIN(s_NORMAL); |
142 | return (STRING); |
143 | } |
144 | . { |
145 | if (lex__ptr > |
146 | lex__buff + sizeof(lex__buff) - 8) { |
147 | moan("string too long at line %i", |
148 | lex_line); |
149 | *lex__ptr++ = 0; |
150 | yylval.s = lex__buff; |
151 | BEGIN(s_NORMAL); |
152 | return (STRING); |
153 | } |
154 | *lex__ptr++ = yytext[0]; |
155 | } |
156 | } |
157 | |
158 | %% |
159 | |
160 | /*----- Support routines --------------------------------------------------*/ |
161 | |
162 | /* --- @lexer_scan@ --- * |
163 | * |
164 | * Arguments: @FILE *fp@ = pointer to a stream object to scan |
165 | * |
166 | * Returns: --- |
167 | * |
168 | * Use: Initialises the scanner ready to parse from the given |
169 | * stream. |
170 | */ |
171 | |
172 | void lexer_scan(FILE *fp) |
173 | { |
174 | yyin = fp; |
175 | lex_line = 1; |
176 | BEGIN(INITIAL); |
177 | } |
178 | |
179 | /*----- That's all, folks -------------------------------------------------*/ |