chiark / gitweb /
Quick lick of paint before we really get started.
[anag] / util.c
CommitLineData
6e403221 1/* -*-c-*-
2 *
6e403221 3 * Various useful utilities, stolen from mLib
4 *
5 * (c) 2001 Mark Wooding
6 */
7
0279756e 8/*----- Licensing notice --------------------------------------------------*
6e403221 9 *
10 * This file is part of Anag: a simple wordgame helper.
11 *
12 * Anag is free software; you can redistribute it and/or modify
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.
0279756e 16 *
6e403221 17 * Anag is distributed in the hope that it will be useful,
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.
0279756e 21 *
6e403221 22 * You should have received a copy of the GNU General Public License
23 * along with Anag; if not, write to the Free Software Foundation,
24 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
25 */
26
6e403221 27/*----- Header files ------------------------------------------------------*/
28
29#include "anag.h"
30
31/*----- Static variables --------------------------------------------------*/
32
33static const char *quis = "<unset>";
34
35/*----- Error reporting ---------------------------------------------------*/
36
37/* --- @ego@ --- *
38 *
39 * Arguments: @const char *p@ = pointer to program name
40 *
41 * Returns: ---
42 *
43 * Use: Stores what the program's name is.
44 */
45
46#ifndef PATHSEP
47# if defined(__riscos)
48# define PATHSEP '.'
49# elif defined(__unix) || defined(unix)
50# define PATHSEP '/'
51# else
52# define PATHSEP '\\'
53# endif
54#endif
55
56void ego(const char *p)
57{
58 const char *q = p;
59 while (*q) {
60 if (*q++ == PATHSEP)
61 p = q;
62 }
63 if (*p == '-')
64 p++;
65 quis = p;
66}
67
68#undef PATHSEP
69
70/* --- @pquis@ --- *
71 *
72 * Arguments: @FILE *fp@ = output stream to write on
73 * @const char *p@ = pointer to string to write
74 *
75 * Returns: Zero if everything worked, EOF if not.
76 *
77 * Use: Writes the string @p@ to the output stream @fp@. Occurrences
78 * of the character `$' in @p@ are replaced by the program name
79 * as reported by @quis@. A `$$' is replaced by a single `$'
80 * sign.
81 */
82
83int pquis(FILE *fp, const char *p)
84{
85 size_t sz;
86
87 while (*p) {
88 sz = strcspn(p, "$");
89 if (sz) {
90 if (fwrite(p, 1, sz, fp) < sz)
91 return (EOF);
92 p += sz;
93 }
94 if (*p == '$') {
95 p++;
96 if (*p == '$') {
97 if (fputc('$', fp) == EOF)
98 return (EOF);
99 p++;
100 } else {
101 if (fputs(quis, fp) == EOF)
102 return (EOF);
103 }
104 }
105 }
106 return (0);
107}
108
109/* --- @die@ --- *
110 *
111 * Arguments: @const char *f@ = a @printf@-style format string
112 * @...@ = other arguments
113 *
114 * Returns: Never.
115 *
116 * Use: Reports an error and exits.
117 */
118
119void die(const char *f, ...)
120{
121 va_list ap;
122 va_start(ap, f);
123 fprintf(stderr, "%s: ", quis);
124 vfprintf(stderr, f, ap);
125 va_end(ap);
126 putc('\n', stderr);
94ed9b30 127 exit(EX_FAIL);
6e403221 128}
129
130/*----- Memory allocation -------------------------------------------------*/
131
132/* --- @xmalloc@ --- *
133 *
134 * Arguments: @size_t sz@ = size of block to allocate
135 *
136 * Returns: Pointer to allocated block.
137 *
138 * Use: Allocates memory. If there's not enough memory, the
139 * program exits.
140 */
141
142void *xmalloc(size_t sz)
143{
144 void *p = malloc(sz);
145 if (!p)
146 die("not enough memory");
147 return (p);
148}
149
150/* --- @xrealloc@ --- *
151 *
152 * Arguments: @void *p@ = a pointer to allocated memory
153 * @size_t sz@ = new size of block wanted
154 *
155 * Returns: Pointer to resized block.
156 *
157 * Use: Resizes an allocated block. If there's not enough memory,
158 * the program exits.
159 */
160
161void *xrealloc(void *p, size_t sz)
162{
163 p = realloc(p, sz);
164 if (!p)
165 die("not enough memory");
166 return (p);
167}
168
169/*----- Dynamic string handling -------------------------------------------*/
170
171#define DSTR_INITSZ 64
172
173/* --- @dstr_destroy@ --- *
174 *
175 * Arguments: @dstr *d@ = pointer to a dynamic string block
176 *
177 * Returns: ---
178 *
179 * Use: Reclaims the space used by a dynamic string.
180 */
181
182void dstr_destroy(dstr *d) { free(d->buf); d->len = 0; d->sz = 0; }
183
184/* --- @dstr_reset@ --- *
185 *
186 * Arguments: @dstr *d@ = pointer to a dynamic string block
187 *
188 * Returns: ---
189 *
190 * Use: Resets a string so that new data gets put at the beginning.
191 */
192
193void dstr_reset(dstr *d) { d->len = 0; }
194
195/* --- @dstr_ensure@ --- *
196 *
197 * Arguments: @dstr *d@ = pointer to a dynamic string block
198 * @size_t sz@ = amount of free space to ensure
199 *
200 * Returns: ---
201 *
202 * Use: Ensures that at least @sz@ bytes are available in the
203 * given string.
204 */
205
206void dstr_ensure(dstr *d, size_t sz)
207{
208 size_t rq = d->len + sz;
209 size_t nsz;
210
211 /* --- If we have enough space, just leave it --- */
212
213 if (rq <= d->sz)
214 return;
215
216 /* --- Grow the buffer --- */
217
218 nsz = d->sz;
219
220 if (nsz == 0)
221 nsz = (DSTR_INITSZ >> 1);
222 do nsz <<= 1; while (nsz < rq);
223
224 if (d->buf)
225 d->buf = xrealloc(d->buf, nsz);
226 else
227 d->buf = xmalloc(nsz);
228 d->sz = nsz;
229}
230
231/* --- @dstr_putline@ --- *
232 *
233 * Arguments: @dstr *d@ = pointer to a dynamic string block
234 * @FILE *fp@ = a stream to read from
235 *
236 * Returns: The number of characters read into the buffer, or @EOF@ if
237 * end-of-file was reached before any characters were read.
238 *
239 * Use: Appends the next line from the given input stream to the
240 * string. A trailing newline is not added; a trailing null
241 * byte is appended, as for @dstr_putz@.
242 */
243
244int dstr_putline(dstr *d, FILE *fp)
245{
246 size_t left = d->sz - d->len;
247 size_t off = d->len;
248 int rd = 0;
249 int ch;
250
251 for (;;) {
252
253 /* --- Read the next byte --- */
254
255 ch = getc(fp);
256
257 /* --- End-of-file when no characters read is special --- */
258
259 if (ch == EOF && !rd)
260 return (EOF);
261
262 /* --- Make sure there's some buffer space --- */
263
264 if (!left) {
265 d->len = off;
266 dstr_ensure(d, 1);
267 left = d->sz - off;
268 }
269
270 /* --- End-of-file or newline ends the loop --- */
271
272 if (ch == EOF || ch == '\n') {
273 d->buf[off] = 0;
274 d->len = off;
275 return rd;
276 }
277
278 /* --- Append the character and continue --- */
279
280 d->buf[off++] = ch;
281 left--; rd++;
282 }
283}
284
285/*----- That's all, folks -------------------------------------------------*/