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Reordered and tidied.
[mLib] / dstr.h
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0875b58f 1/* -*-c-*-
2 *
3 * $Id: dstr.h,v 1.1 1998/06/17 23:44:42 mdw Exp $
4 *
5 * Handle dynamically growing strings
6 *
7 * (c) 1998 Straylight/Edgeware
8 */
9
10/*----- Licensing notice --------------------------------------------------*
11 *
12 * This file is part of the mLib utilities library.
13 *
14 * mLib 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 * mLib 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 mLib; if not, write to the Free Software Foundation,
26 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
27 */
28
29/*----- Revision history --------------------------------------------------*
30 *
31 * $Log: dstr.h,v $
32 * Revision 1.1 1998/06/17 23:44:42 mdw
33 * Initial revision
34 *
35 */
36
37#ifndef DSTR_H
38#define DSTR_H
39
40#ifdef __cplusplus
41 extern "C" {
42#endif
43
44/*----- Rationale ---------------------------------------------------------*
45 *
46 * This file declares what is hopefully a fairly useful collection of
47 * primitive string handling functions. The idea is that the strings
48 * allocate memory for themselves as required. The @dstr@ routines don't
49 * assume any sort of terminator character, so arbitrary binary data can
50 * be stored in a dynamic string. With luck, this should put a stop to
51 * any buffer overflow problems.
52 */
53
54/*----- Header files ------------------------------------------------------*/
55
56#include <stdio.h>
57
58/*----- Data structures ---------------------------------------------------*/
59
60typedef struct dstr {
61 char *buf; /* Pointer to string buffer */
62 size_t sz; /* Size of the buffer */
63 size_t len; /* Length of the string */
64} dstr;
65
66/*----- Functions provided ------------------------------------------------*/
67
68/* --- @dstr_create@ --- *
69 *
70 * Arguments: @dstr *d@ = pointer to a dynamic string block
71 *
72 * Returns: ---
73 *
74 * Use: Initialises a dynamic string.
75 */
76
77extern void dstr_create(dstr */*d*/);
78
79/* --- @dstr_destroy@ --- *
80 *
81 * Arguments: @dstr *d@ = pointer to a dynamic string block
82 *
83 * Returns: ---
84 *
85 * Use: Reclaims the space used by a dynamic string.
86 */
87
88extern void dstr_destroy(dstr */*d*/);
89
90/* --- @dstr_reset@ --- *
91 *
92 * Arguments: @dstr *d@ = pointer to a dynaimc string block
93 *
94 * Returns: ---
95 *
96 * Use: Resets a string so that new data gets put at the beginning.
97 */
98
99extern void dstr_reset(dstr */*d*/);
100
101/* --- @dstr_ensure@ --- *
102 *
103 * Arguments: @dstr *d@ = pointer to a dynamic string block
104 * @size_t sz@ = amount of free space to ensure
105 *
106 * Returns: ---
107 *
108 * Use: Ensures that at least @sz@ bytes are available in the
109 * given string.
110 */
111
112extern void dstr_ensure(dstr */*d*/, size_t /*sz*/);
113
114#define DENSURE(d, rq) do { \
115 if ((d)->len + (rq) > (d)->sz) dstr_ensure((d), (rq)); \
116} while (0)
117
118/* --- @dstr_putc@ --- *
119 *
120 * Arguments: @dstr *d@ = pointer to a dynamic string block
121 * @char ch@ = character to append
122 *
123 * Returns: ---
124 *
125 * Use: Appends a character to a string.
126 */
127
128extern void dstr_putc(dstr */*d*/, char /*ch*/);
129
130#define DPUTC(d, ch) do { \
131 DENSURE((d), 1); \
132 (d)->buf[(d)->len++] = (ch); \
133} while (0)
134
135/* --- @dstr_putz@ --- *
136 *
137 * Arguments: @dstr *d@ = pointer to a dynamic string block
138 *
139 * Returns: ---
140 *
141 * Use: Appends a null byte to a string. The null byte does not
142 * contribute to the string's length, and will be overwritten
143 * by subsequent `put' operations.
144 */
145
146extern void dstr_putz(dstr */*d*/);
147
148#define DPUTZ(d) do { \
149 DENSURE((d), 1); \
150 (d)->buf[(d)->len] = 0; \
151} while (0)
152
153/* --- @dstr_puts@ --- *
154 *
155 * Arguments: @dstr *d@ = pointer to a dynamic string block
156 * @const char *s@ = pointer to string to append
157 *
158 * Returns: ---
159 *
160 * Use: Appends a character string to a string. A trailing null
161 * byte is added, as for @dstr_putz@.
162 */
163
164extern void dstr_puts(dstr */*d*/, const char */*s*/);
165
166#define DPUTS(d, s) do { \
167 size_t sz = strlen(s); \
168 DENSURE((d), sz + 1); \
169 memcpy((d)->buf + (d)->len, (s), sz + 1); \
170 (d)->len += sz; \
171} while (0)
172
173/* --- @dstr_putd@ --- *
174 *
175 * Arguments: @dstr *d@ = pointer to a dynamic string block
176 * @const dstr *s@ = pointer to a dynamic string to append
177 *
178 * Returns: ---
179 *
180 * Use: Appends a dynamic string to a string. A trailing null
181 * byte is added, as for @dstr_putz@.
182 */
183
184extern void dstr_putd(dstr */*d*/, const dstr */*s*/);
185
186#define DPUTD(d, s) do { \
187 DENSURE((d), (s)->len + 1); \
188 memcpy((d)->buf + (d)->len, (s)->buf, (s)->len); \
189 (d)->len += (s)->len; \
190 (d)->buf[(d)->len] = 0; \
191} while (0)
192
193/* --- @dstr_putm@ --- *
194 *
195 * Arguments: @dstr *d@ = pointer to a dynamic string block
196 * @const void *p@ = pointer to a block to append
197 * @size_t sz@ = size of the block
198 *
199 * Returns: Appends an arbitrary data block to a string. No trailing
200 * null is appended.
201 */
202
203extern void dstr_putm(dstr */*d*/, const void */*p*/, size_t /*sz*/);
204
205#define DPUTM(d, p, sz) do { \
206 DENSURE((d), (sz)); \
207 memcpy((d)->buf + (d)->len, (p), (sz)); \
208 (d)->len += (sz); \
209} while (0)
210
211/* --- @dstr_tidy@ --- *
212 *
213 * Arguments: @dstr *d@ = pointer to a dynamic string block
214 *
215 * Returns: ---
216 *
217 * Use: Reduces the amount of memory used by a string. A trailing
218 * null byte is added, as for @dstr_putz@.
219 */
220
221extern void dstr_tidy(dstr */*d*/);
222
223/* --- @dstr_putline@ --- *
224 *
225 * Arguments: @dstr *d@ = pointer to a dynamic string block
226 * @FILE *fp@ = a stream to read from
227 *
228 * Returns: The number of characters read into the buffer, or @EOF@ if
229 * end-of-file was reached before any characters were read.
230 *
231 * Use: Appends the next line from the given input stream to the
232 * string. A trailing newline is not added; a trailing null
233 * byte is appended, as for @dstr_putz@.
234 */
235
236extern int dstr_putline(dstr */*d*/, FILE */*fp*/);
237
238/* --- @dstr_write@ --- *
239 *
240 * Arguments: @dstr *d@ = pointer to a dynamic string block
241 * @FILE *fp@ = a stream to write on
242 *
243 * Returns: The number of bytes written (as for @fwrite@).
244 *
245 * Use: Writes a dynamic string to a file.
246 */
247
248extern size_t dstr_write(dstr */*d*/, FILE */*fp*/);
249
250/*----- That's all, folks -------------------------------------------------*/
251
252#ifdef __cplusplus
253 }
254#endif
255
256#endif