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1 | /* -*-c-*- |
2 | * |
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3 | * Character scanners |
4 | * |
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5 | * (c) 1999 Straylight/Edgeware |
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6 | */ |
7 | |
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8 | /*----- Licensing notice --------------------------------------------------* |
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9 | * |
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10 | * This file is part of the `fwd' port forwarder. |
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11 | * |
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12 | * `fwd' is free software; you can redistribute it and/or modify |
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13 | * it under the terms of the GNU General Public License as published by |
14 | * the Free Software Foundation; either version 2 of the License, or |
15 | * (at your option) any later version. |
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16 | * |
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17 | * `fwd' is distributed in the hope that it will be useful, |
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18 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
20 | * GNU General Public License for more details. |
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21 | * |
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22 | * You should have received a copy of the GNU General Public License |
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23 | * along with `fwd'; if not, write to the Free Software Foundation, |
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24 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
25 | */ |
26 | |
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27 | #ifndef SCAN_H |
28 | #define SCAN_H |
29 | |
30 | #ifdef __cplusplus |
31 | extern "C" { |
32 | #endif |
33 | |
34 | /*----- Header files ------------------------------------------------------*/ |
35 | |
36 | #include <stdio.h> |
37 | |
38 | #include <mLib/dstr.h> |
39 | |
40 | /*----- Data structures ---------------------------------------------------*/ |
41 | |
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42 | /* --- A low-level scanner source --- */ |
43 | |
44 | typedef struct scansrc { |
45 | struct scansrc *next; /* Next one in the list */ |
46 | struct scansrc_ops *ops; /* Pointer to operations table */ |
47 | char *src; /* Name of this source */ |
48 | int line; /* Current line number */ |
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49 | dstr pushback; /* Pushback characters */ |
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50 | char *tok; /* Token pushback */ |
51 | unsigned t; /* Token type pushback */ |
52 | } scansrc; |
53 | |
54 | /* --- Scanner source operations --- */ |
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55 | |
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56 | typedef struct scansrc_ops { |
57 | int (*scan)(scansrc */*ss*/); /* Read another character */ |
58 | void (*destroy)(scansrc */*ss*/); /* Destroy an unwanted source */ |
59 | } scansrc_ops; |
60 | |
61 | /* --- A character scanner --- */ |
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62 | |
63 | typedef struct scanner { |
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64 | scansrc *head, **tail; /* Scanner list head and tail */ |
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65 | int t; /* Token type */ |
66 | dstr d; /* Current token value */ |
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67 | const char *wbegin, *wcont; /* Parsing exception strings */ |
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68 | } scanner; |
69 | |
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70 | /*----- Particular scanner types ------------------------------------------*/ |
71 | |
72 | /* --- @scan_file@ --- * |
73 | * |
74 | * Arguments: @FILE *fp@ = pointer to file descriptor |
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75 | * @const char *name@ = pointer to source file name |
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76 | * @unsigned f@ = flags |
77 | * |
78 | * Returns: A scanner source. |
79 | * |
80 | * Use: Creates a new scanner source for reading from a file. |
81 | */ |
82 | |
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83 | #define SCF_NOCLOSE 1u /* Don't close @fp@ when finished */ |
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84 | |
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85 | extern scansrc *scan_file(FILE */*fp*/, const char */*name*/, |
86 | unsigned /*f*/); |
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87 | |
88 | /* --- @scan_argv@ --- * |
89 | * |
90 | * Arguments: @char **av@ = pointer to argument array (null terminated) |
91 | * |
92 | * Returns: A scanner source. |
93 | * |
94 | * Use: Creates a new scanner source for reading from an @argv@ |
95 | * array. |
96 | */ |
97 | |
98 | extern scansrc *scan_argv(char **/*av*/); |
99 | |
100 | /*----- General scanner handling ------------------------------------------*/ |
101 | |
102 | /* --- @scan@ --- * |
103 | * |
104 | * Arguments: @scanner *sc@ = pointer to main scanner context |
105 | * |
106 | * Returns: Character read, or end-of-file. |
107 | * |
108 | * Use: Scans a character from a source of characters. |
109 | */ |
110 | |
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111 | extern int scan(scanner */*sc*/); |
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112 | |
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113 | /* --- @unscan@ --- * |
114 | * |
115 | * Arguments: @scanner *sc@ = pointer to main scanner context |
116 | * @int ch@ = character to unscan |
117 | * |
118 | * Returns: --- |
119 | * |
120 | * Use: Scans a character from a source of characters. |
121 | */ |
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122 | |
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123 | extern void unscan(scanner */*sc*/, int /*ch*/); |
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124 | |
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125 | /* --- @scan_push@ --- * |
126 | * |
127 | * Arguments: @scanner *sc@ = pointer to main scanner context |
128 | * @scansrc *ss@ = souorce to push |
129 | * |
130 | * Returns: --- |
131 | * |
132 | * Use: Pushes a scanner source onto the front of the queue. |
133 | */ |
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134 | |
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135 | extern void scan_push(scanner */*sc*/, scansrc */*ss*/); |
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136 | |
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137 | /* --- @scan_add@ --- * |
138 | * |
139 | * Arguments: @scanner *sc@ = pointer to main scanner context |
140 | * @scansrc *ss@ = souorce to push |
141 | * |
142 | * Returns: --- |
143 | * |
144 | * Use: Adds a scanner source onto the end of the queue. |
145 | */ |
146 | |
147 | extern void scan_add(scanner */*sc*/, scansrc */*ss*/); |
148 | |
149 | /* --- @scan_create@ --- * |
150 | * |
151 | * Arguments: @scanner *sc@ = scanner context to initialize |
152 | * |
153 | * Returns: --- |
154 | * |
155 | * Use: Initializes a scanner block ready for use. |
156 | */ |
157 | |
158 | extern void scan_create(scanner */*sc*/); |
159 | |
160 | /* --- @scan_destroy@ --- * |
161 | * |
162 | * Arguments: @scanner *sc@ = pointer to scanner context |
163 | * |
164 | * Returns: --- |
165 | * |
166 | * Use: Destroys a scanner and all the sources attached to it. |
167 | */ |
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168 | |
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169 | extern void scan_destroy(scanner */*sc*/); |
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170 | |
171 | /*----- That's all, folks -------------------------------------------------*/ |
172 | |
173 | #ifdef __cplusplus |
174 | } |
175 | #endif |
176 | |
177 | #endif |