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New functions `dstr_putf' and `dstr_vputf' which do `printf'-style
[mLib] / dstr.h
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0875b58f 1/* -*-c-*-
2 *
00c7638b 3 * $Id: dstr.h,v 1.2 1998/12/15 23:53:23 mdw Exp $
0875b58f 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 $
00c7638b 32 * Revision 1.2 1998/12/15 23:53:23 mdw
33 * New functions `dstr_putf' and `dstr_vputf' which do `printf'-style
34 * formatting in a safe way.
35 *
36 * Revision 1.1.1.1 1998/06/17 23:44:42 mdw
37 * Initial version of mLib
0875b58f 38 *
39 */
40
41#ifndef DSTR_H
42#define DSTR_H
43
44#ifdef __cplusplus
45 extern "C" {
46#endif
47
48/*----- Rationale ---------------------------------------------------------*
49 *
50 * This file declares what is hopefully a fairly useful collection of
51 * primitive string handling functions. The idea is that the strings
52 * allocate memory for themselves as required. The @dstr@ routines don't
53 * assume any sort of terminator character, so arbitrary binary data can
54 * be stored in a dynamic string. With luck, this should put a stop to
55 * any buffer overflow problems.
56 */
57
58/*----- Header files ------------------------------------------------------*/
59
00c7638b 60#include <stdarg.h>
0875b58f 61#include <stdio.h>
62
63/*----- Data structures ---------------------------------------------------*/
64
65typedef struct dstr {
66 char *buf; /* Pointer to string buffer */
67 size_t sz; /* Size of the buffer */
68 size_t len; /* Length of the string */
69} dstr;
70
71/*----- Functions provided ------------------------------------------------*/
72
73/* --- @dstr_create@ --- *
74 *
75 * Arguments: @dstr *d@ = pointer to a dynamic string block
76 *
77 * Returns: ---
78 *
79 * Use: Initialises a dynamic string.
80 */
81
82extern void dstr_create(dstr */*d*/);
83
84/* --- @dstr_destroy@ --- *
85 *
86 * Arguments: @dstr *d@ = pointer to a dynamic string block
87 *
88 * Returns: ---
89 *
90 * Use: Reclaims the space used by a dynamic string.
91 */
92
93extern void dstr_destroy(dstr */*d*/);
94
95/* --- @dstr_reset@ --- *
96 *
97 * Arguments: @dstr *d@ = pointer to a dynaimc string block
98 *
99 * Returns: ---
100 *
101 * Use: Resets a string so that new data gets put at the beginning.
102 */
103
104extern void dstr_reset(dstr */*d*/);
105
106/* --- @dstr_ensure@ --- *
107 *
108 * Arguments: @dstr *d@ = pointer to a dynamic string block
109 * @size_t sz@ = amount of free space to ensure
110 *
111 * Returns: ---
112 *
113 * Use: Ensures that at least @sz@ bytes are available in the
114 * given string.
115 */
116
117extern void dstr_ensure(dstr */*d*/, size_t /*sz*/);
118
119#define DENSURE(d, rq) do { \
120 if ((d)->len + (rq) > (d)->sz) dstr_ensure((d), (rq)); \
121} while (0)
122
123/* --- @dstr_putc@ --- *
124 *
125 * Arguments: @dstr *d@ = pointer to a dynamic string block
126 * @char ch@ = character to append
127 *
128 * Returns: ---
129 *
130 * Use: Appends a character to a string.
131 */
132
133extern void dstr_putc(dstr */*d*/, char /*ch*/);
134
135#define DPUTC(d, ch) do { \
136 DENSURE((d), 1); \
137 (d)->buf[(d)->len++] = (ch); \
138} while (0)
139
140/* --- @dstr_putz@ --- *
141 *
142 * Arguments: @dstr *d@ = pointer to a dynamic string block
143 *
144 * Returns: ---
145 *
146 * Use: Appends a null byte to a string. The null byte does not
147 * contribute to the string's length, and will be overwritten
148 * by subsequent `put' operations.
149 */
150
151extern void dstr_putz(dstr */*d*/);
152
153#define DPUTZ(d) do { \
154 DENSURE((d), 1); \
155 (d)->buf[(d)->len] = 0; \
156} while (0)
157
158/* --- @dstr_puts@ --- *
159 *
160 * Arguments: @dstr *d@ = pointer to a dynamic string block
161 * @const char *s@ = pointer to string to append
162 *
163 * Returns: ---
164 *
165 * Use: Appends a character string to a string. A trailing null
166 * byte is added, as for @dstr_putz@.
167 */
168
169extern void dstr_puts(dstr */*d*/, const char */*s*/);
170
171#define DPUTS(d, s) do { \
172 size_t sz = strlen(s); \
173 DENSURE((d), sz + 1); \
174 memcpy((d)->buf + (d)->len, (s), sz + 1); \
175 (d)->len += sz; \
176} while (0)
177
00c7638b 178/* --- @dstr_vputf@ --- *
179 *
180 * Arguments: @dstr *d@ = pointer to a dynamic string block
181 * @const char *p@ = pointer to @printf@-style format string
182 * @va_list ap@ = argument handle
183 *
184 * Returns: ---
185 *
186 * Use: As for @dstr_putf@, but may be used as a back-end to user-
187 * supplied functions with @printf@-style interfaces.
188 */
189
190extern int dstr_vputf(dstr */*d*/, const char */*p*/, va_list /*ap*/);
191
192/* --- @dstr_putf@ --- *
193 *
194 * Arguments: @dstr *d@ = pointer to a dynamic string block
195 * @const char *p@ = pointer to @printf@-style format string
196 * @...@ = argument handle
197 *
198 * Returns: ---
199 *
200 * Use: Writes a piece of text to a dynamic string, doing @printf@-
201 * style substitutions as it goes. Intended to be robust if
202 * faced with malicious arguments, but not if the format string
203 * itself is malicious.
204 */
205
206extern int dstr_putf(dstr */*d*/, const char */*p*/, ...);
207
0875b58f 208/* --- @dstr_putd@ --- *
209 *
210 * Arguments: @dstr *d@ = pointer to a dynamic string block
211 * @const dstr *s@ = pointer to a dynamic string to append
212 *
213 * Returns: ---
214 *
215 * Use: Appends a dynamic string to a string. A trailing null
216 * byte is added, as for @dstr_putz@.
217 */
218
219extern void dstr_putd(dstr */*d*/, const dstr */*s*/);
220
221#define DPUTD(d, s) do { \
222 DENSURE((d), (s)->len + 1); \
223 memcpy((d)->buf + (d)->len, (s)->buf, (s)->len); \
224 (d)->len += (s)->len; \
225 (d)->buf[(d)->len] = 0; \
226} while (0)
227
228/* --- @dstr_putm@ --- *
229 *
230 * Arguments: @dstr *d@ = pointer to a dynamic string block
231 * @const void *p@ = pointer to a block to append
232 * @size_t sz@ = size of the block
233 *
234 * Returns: Appends an arbitrary data block to a string. No trailing
235 * null is appended.
236 */
237
238extern void dstr_putm(dstr */*d*/, const void */*p*/, size_t /*sz*/);
239
240#define DPUTM(d, p, sz) do { \
241 DENSURE((d), (sz)); \
242 memcpy((d)->buf + (d)->len, (p), (sz)); \
243 (d)->len += (sz); \
244} while (0)
245
246/* --- @dstr_tidy@ --- *
247 *
248 * Arguments: @dstr *d@ = pointer to a dynamic string block
249 *
250 * Returns: ---
251 *
252 * Use: Reduces the amount of memory used by a string. A trailing
253 * null byte is added, as for @dstr_putz@.
254 */
255
256extern void dstr_tidy(dstr */*d*/);
257
258/* --- @dstr_putline@ --- *
259 *
260 * Arguments: @dstr *d@ = pointer to a dynamic string block
261 * @FILE *fp@ = a stream to read from
262 *
263 * Returns: The number of characters read into the buffer, or @EOF@ if
264 * end-of-file was reached before any characters were read.
265 *
266 * Use: Appends the next line from the given input stream to the
267 * string. A trailing newline is not added; a trailing null
268 * byte is appended, as for @dstr_putz@.
269 */
270
271extern int dstr_putline(dstr */*d*/, FILE */*fp*/);
272
273/* --- @dstr_write@ --- *
274 *
275 * Arguments: @dstr *d@ = pointer to a dynamic string block
276 * @FILE *fp@ = a stream to write on
277 *
278 * Returns: The number of bytes written (as for @fwrite@).
279 *
280 * Use: Writes a dynamic string to a file.
281 */
282
283extern size_t dstr_write(dstr */*d*/, FILE */*fp*/);
284
285/*----- That's all, folks -------------------------------------------------*/
286
287#ifdef __cplusplus
288 }
289#endif
290
291#endif