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c84142e8 UD |
1 | /* Word-wrapping and line-truncating streams |
2 | Copyright (C) 1997 Free Software Foundation, Inc. | |
3 | This file is part of the GNU C Library. | |
4 | Written by Miles Bader <miles@gnu.ai.mit.edu>. | |
5 | ||
6 | The GNU C Library is free software; you can redistribute it and/or | |
7 | modify it under the terms of the GNU Library General Public License as | |
8 | published by the Free Software Foundation; either version 2 of the | |
9 | License, or (at your option) any later version. | |
10 | ||
11 | The GNU C Library is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | Library General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU Library General Public | |
17 | License along with the GNU C Library; see the file COPYING.LIB. If not, | |
18 | write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
19 | Boston, MA 02111-1307, USA. */ | |
20 | ||
21 | /* This package emulates glibc `line_wrap_stream' semantics for systems that | |
22 | don't have that. */ | |
23 | ||
24 | #ifdef HAVE_CONFIG_H | |
25 | #include <config.h> | |
26 | #endif | |
27 | ||
28 | #include <stdlib.h> | |
29 | #include <string.h> | |
30 | #include <errno.h> | |
31 | #include <stdarg.h> | |
32 | #include <ctype.h> | |
33 | ||
34 | #include "argp-fmtstream.h" | |
35 | #include "argp-namefrob.h" | |
36 | ||
37 | #ifndef ARGP_FMTSTREAM_USE_LINEWRAP | |
38 | ||
39 | #ifndef isblank | |
40 | #define isblank(ch) ((ch)==' ' || (ch)=='\t') | |
41 | #endif | |
42 | ||
43 | #define INIT_BUF_SIZE 200 | |
44 | #define PRINTF_SIZE_GUESS 150 | |
45 | \f | |
46 | /* Return an argp_fmtstream that outputs to STREAM, and which prefixes lines | |
47 | written on it with LMARGIN spaces and limits them to RMARGIN columns | |
48 | total. If WMARGIN >= 0, words that extend past RMARGIN are wrapped by | |
49 | replacing the whitespace before them with a newline and WMARGIN spaces. | |
50 | Otherwise, chars beyond RMARGIN are simply dropped until a newline. | |
51 | Returns NULL if there was an error. */ | |
52 | argp_fmtstream_t | |
53 | __argp_make_fmtstream (FILE *stream, | |
54 | size_t lmargin, size_t rmargin, ssize_t wmargin) | |
55 | { | |
56 | argp_fmtstream_t fs = malloc (sizeof (struct argp_fmtstream)); | |
57 | if (fs) | |
58 | { | |
59 | fs->stream = stream; | |
60 | ||
61 | fs->lmargin = lmargin; | |
62 | fs->rmargin = rmargin; | |
63 | fs->wmargin = wmargin; | |
64 | fs->point_col = 0; | |
65 | fs->point_offs = 0; | |
66 | ||
67 | fs->buf = malloc (INIT_BUF_SIZE); | |
68 | if (! fs->buf) | |
69 | { | |
70 | free (fs); | |
71 | fs = 0; | |
72 | } | |
73 | else | |
74 | { | |
75 | fs->p = fs->buf; | |
76 | fs->end = fs->buf + INIT_BUF_SIZE; | |
77 | } | |
78 | } | |
79 | ||
80 | return fs; | |
81 | } | |
82 | #ifdef weak_alias | |
83 | weak_alias (__argp_make_fmtstream, argp_make_fmtstream) | |
84 | #endif | |
85 | ||
86 | /* Flush FS to its stream, and free it (but don't close the stream). */ | |
87 | void | |
88 | __argp_fmtstream_free (argp_fmtstream_t fs) | |
89 | { | |
90 | __argp_fmtstream_update (fs); | |
91 | if (fs->p > fs->buf) | |
92 | fwrite (fs->buf, 1, fs->p - fs->buf, fs->stream); | |
93 | free (fs->buf); | |
94 | free (fs); | |
95 | } | |
96 | #ifdef weak_alias | |
97 | weak_alias (__argp_fmtstream_free, argp_fmtstream_free) | |
98 | #endif | |
99 | \f | |
100 | /* Process FS's buffer so that line wrapping is done from POINT_OFFS to the | |
101 | end of its buffer. This code is mostly from glibc stdio/linewrap.c. */ | |
102 | void | |
103 | __argp_fmtstream_update (argp_fmtstream_t fs) | |
104 | { | |
105 | char *buf, *nl; | |
106 | size_t len; | |
107 | ||
108 | /* Scan the buffer for newlines. */ | |
109 | buf = fs->buf + fs->point_offs; | |
110 | while (buf < fs->p) | |
111 | { | |
112 | size_t r; | |
113 | ||
114 | if (fs->point_col == 0 && fs->lmargin != 0) | |
115 | { | |
116 | /* We are starting a new line. Print spaces to the left margin. */ | |
117 | const size_t pad = fs->lmargin; | |
118 | if (fs->p + pad < fs->end) | |
119 | { | |
120 | /* We can fit in them in the buffer by moving the | |
121 | buffer text up and filling in the beginning. */ | |
122 | memmove (buf + pad, buf, fs->p - buf); | |
123 | fs->p += pad; /* Compensate for bigger buffer. */ | |
124 | memset (buf, ' ', pad); /* Fill in the spaces. */ | |
125 | buf += pad; /* Don't bother searching them. */ | |
126 | } | |
127 | else | |
128 | { | |
129 | /* No buffer space for spaces. Must flush. */ | |
130 | size_t i; | |
131 | for (i = 0; i < pad; i++) | |
132 | putc (' ', fs->stream); | |
133 | } | |
134 | fs->point_col = pad; | |
135 | } | |
136 | ||
137 | len = fs->p - buf; | |
138 | nl = memchr (buf, '\n', len); | |
139 | ||
140 | if (fs->point_col < 0) | |
141 | fs->point_col = 0; | |
142 | ||
143 | if (!nl) | |
144 | { | |
145 | /* The buffer ends in a partial line. */ | |
146 | ||
147 | if (fs->point_col + len < fs->rmargin) | |
148 | { | |
149 | /* The remaining buffer text is a partial line and fits | |
150 | within the maximum line width. Advance point for the | |
151 | characters to be written and stop scanning. */ | |
152 | fs->point_col += len; | |
153 | break; | |
154 | } | |
155 | else | |
156 | /* Set the end-of-line pointer for the code below to | |
157 | the end of the buffer. */ | |
158 | nl = fs->p; | |
159 | } | |
c131718c | 160 | else if (fs->point_col + (nl - buf) < (ssize_t) fs->rmargin) |
c84142e8 UD |
161 | { |
162 | /* The buffer contains a full line that fits within the maximum | |
163 | line width. Reset point and scan the next line. */ | |
164 | fs->point_col = 0; | |
165 | buf = nl + 1; | |
166 | continue; | |
167 | } | |
168 | ||
169 | /* This line is too long. */ | |
170 | r = fs->rmargin - 1; | |
171 | ||
172 | if (fs->wmargin < 0) | |
173 | { | |
174 | /* Truncate the line by overwriting the excess with the | |
175 | newline and anything after it in the buffer. */ | |
176 | if (nl < fs->p) | |
177 | { | |
178 | memmove (buf + (r - fs->point_col), nl, fs->p - nl); | |
179 | fs->p -= buf + (r - fs->point_col) - nl; | |
180 | /* Reset point for the next line and start scanning it. */ | |
181 | fs->point_col = 0; | |
182 | buf += r + 1; /* Skip full line plus \n. */ | |
183 | } | |
184 | else | |
185 | { | |
186 | /* The buffer ends with a partial line that is beyond the | |
187 | maximum line width. Advance point for the characters | |
188 | written, and discard those past the max from the buffer. */ | |
189 | fs->point_col += len; | |
190 | fs->p -= fs->point_col - r; | |
191 | break; | |
192 | } | |
193 | } | |
194 | else | |
195 | { | |
196 | /* Do word wrap. Go to the column just past the maximum line | |
197 | width and scan back for the beginning of the word there. | |
198 | Then insert a line break. */ | |
199 | ||
200 | char *p, *nextline; | |
201 | int i; | |
202 | ||
203 | p = buf + (r + 1 - fs->point_col); | |
204 | while (p >= buf && !isblank (*p)) | |
205 | --p; | |
206 | nextline = p + 1; /* This will begin the next line. */ | |
207 | ||
208 | if (nextline > buf) | |
209 | { | |
210 | /* Swallow separating blanks. */ | |
211 | if (p > buf) | |
212 | do | |
213 | --p; | |
214 | while (p > buf && isblank (*p)); | |
215 | nl = p + 1; /* The newline will replace the first blank. */ | |
216 | } | |
217 | else | |
218 | { | |
219 | /* A single word that is greater than the maximum line width. | |
220 | Oh well. Put it on an overlong line by itself. */ | |
221 | p = buf + (r + 1 - fs->point_col); | |
222 | /* Find the end of the long word. */ | |
223 | do | |
224 | ++p; | |
225 | while (p < nl && !isblank (*p)); | |
226 | if (p == nl) | |
227 | { | |
228 | /* It already ends a line. No fussing required. */ | |
229 | fs->point_col = 0; | |
230 | buf = nl + 1; | |
231 | continue; | |
232 | } | |
233 | /* We will move the newline to replace the first blank. */ | |
234 | nl = p; | |
235 | /* Swallow separating blanks. */ | |
236 | do | |
237 | ++p; | |
238 | while (isblank (*p)); | |
239 | /* The next line will start here. */ | |
240 | nextline = p; | |
241 | } | |
242 | ||
5a97622d UD |
243 | /* Note: There are a bunch of tests below for |
244 | NEXTLINE == BUF + LEN + 1; this case is where NL happens to fall | |
245 | at the end of the buffer, and NEXTLINE is in fact empty (and so | |
246 | we need not be careful to maintain its contents). */ | |
247 | ||
248 | if (nextline == buf + len + 1 | |
249 | ? fs->end - nl < fs->wmargin + 1 | |
250 | : nextline - (nl + 1) < fs->wmargin) | |
c84142e8 UD |
251 | /* The margin needs more blanks than we removed. */ |
252 | if (fs->end - fs->p > fs->wmargin + 1) | |
253 | /* Make some space for them. */ | |
254 | { | |
255 | size_t mv = fs->p - nextline; | |
256 | memmove (nl + 1 + fs->wmargin, nextline, mv); | |
257 | nextline = nl + 1 + fs->wmargin; | |
258 | len = nextline + mv - buf; | |
259 | *nl++ = '\n'; | |
260 | } | |
261 | else | |
262 | /* Output the first line so we can use the space. */ | |
263 | { | |
264 | if (nl > fs->buf) | |
265 | fwrite (fs->buf, 1, nl - fs->buf, fs->stream); | |
266 | putc ('\n', fs->stream); | |
267 | len += buf - fs->buf; | |
268 | nl = buf = fs->buf; | |
269 | } | |
270 | else | |
271 | /* We can fit the newline and blanks in before | |
272 | the next word. */ | |
273 | *nl++ = '\n'; | |
274 | ||
5a97622d UD |
275 | if (nextline - nl >= fs->wmargin |
276 | || (nextline == buf + len + 1 && fs->end - nextline >= fs->wmargin)) | |
c84142e8 UD |
277 | /* Add blanks up to the wrap margin column. */ |
278 | for (i = 0; i < fs->wmargin; ++i) | |
279 | *nl++ = ' '; | |
280 | else | |
281 | for (i = 0; i < fs->wmargin; ++i) | |
282 | putc (' ', fs->stream); | |
283 | ||
284 | /* Copy the tail of the original buffer into the current buffer | |
285 | position. */ | |
5a97622d | 286 | if (nl < nextline) |
c84142e8 UD |
287 | memmove (nl, nextline, buf + len - nextline); |
288 | len -= nextline - buf; | |
289 | ||
290 | /* Continue the scan on the remaining lines in the buffer. */ | |
291 | buf = nl; | |
292 | ||
293 | /* Restore bufp to include all the remaining text. */ | |
294 | fs->p = nl + len; | |
295 | ||
296 | /* Reset the counter of what has been output this line. If wmargin | |
297 | is 0, we want to avoid the lmargin getting added, so we set | |
298 | point_col to a magic value of -1 in that case. */ | |
299 | fs->point_col = fs->wmargin ? fs->wmargin : -1; | |
300 | } | |
301 | } | |
302 | ||
303 | /* Remember that we've scanned as far as the end of the buffer. */ | |
304 | fs->point_offs = fs->p - fs->buf; | |
305 | } | |
306 | \f | |
307 | /* Ensure that FS has space for AMOUNT more bytes in its buffer, either by | |
308 | growing the buffer, or by flushing it. True is returned iff we succeed. */ | |
309 | int | |
310 | __argp_fmtstream_ensure (struct argp_fmtstream *fs, size_t amount) | |
311 | { | |
c131718c | 312 | if ((size_t) (fs->end - fs->p) < amount) |
c84142e8 UD |
313 | { |
314 | ssize_t wrote; | |
315 | ||
316 | /* Flush FS's buffer. */ | |
317 | __argp_fmtstream_update (fs); | |
318 | ||
319 | wrote = fwrite (fs->buf, 1, fs->p - fs->buf, fs->stream); | |
320 | if (wrote == fs->p - fs->buf) | |
321 | { | |
322 | fs->p = fs->buf; | |
323 | fs->point_offs = 0; | |
324 | } | |
325 | else | |
326 | { | |
327 | fs->p -= wrote; | |
328 | fs->point_offs -= wrote; | |
329 | memmove (fs->buf, fs->buf + wrote, fs->p - fs->buf); | |
330 | return 0; | |
331 | } | |
332 | ||
c131718c | 333 | if ((size_t) (fs->end - fs->buf) < amount) |
c84142e8 UD |
334 | /* Gotta grow the buffer. */ |
335 | { | |
336 | size_t new_size = fs->end - fs->buf + amount; | |
337 | char *new_buf = realloc (fs->buf, new_size); | |
338 | ||
339 | if (! new_buf) | |
340 | { | |
341 | __set_errno (ENOMEM); | |
342 | return 0; | |
343 | } | |
344 | ||
345 | fs->buf = new_buf; | |
346 | fs->end = new_buf + new_size; | |
347 | fs->p = fs->buf; | |
348 | } | |
349 | } | |
350 | ||
351 | return 1; | |
352 | } | |
353 | \f | |
354 | ssize_t | |
355 | __argp_fmtstream_printf (struct argp_fmtstream *fs, const char *fmt, ...) | |
356 | { | |
c131718c | 357 | int out; |
c84142e8 UD |
358 | size_t size_guess = PRINTF_SIZE_GUESS; /* How much space to reserve. */ |
359 | ||
360 | do | |
361 | { | |
362 | va_list args; | |
363 | ||
364 | if (! __argp_fmtstream_ensure (fs, size_guess)) | |
365 | return -1; | |
366 | size_guess += size_guess; | |
367 | ||
368 | va_start (args, fmt); | |
369 | out = __vsnprintf (fs->p, fs->end - fs->p, fmt, args); | |
370 | va_end (args); | |
371 | } | |
372 | while (out == -1); | |
373 | ||
374 | fs->p += out; | |
375 | ||
376 | return out; | |
377 | } | |
378 | #ifdef weak_alias | |
379 | weak_alias (__argp_fmtstream_printf, argp_fmtstream_printf) | |
380 | #endif | |
381 | ||
382 | #endif /* !ARGP_FMTSTREAM_USE_LINEWRAP */ |