1 /*
2 Internal file viewer for the Midnight Commander
3 Functions for datasources
4
5 Copyright (C) 1994-2021
6 Free Software Foundation, Inc.
7
8 Written by:
9 Miguel de Icaza, 1994, 1995, 1998
10 Janne Kukonlehto, 1994, 1995
11 Jakub Jelinek, 1995
12 Joseph M. Hinkle, 1996
13 Norbert Warmuth, 1997
14 Pavel Machek, 1998
15 Roland Illig <roland.illig@gmx.de>, 2004, 2005
16 Slava Zanko <slavazanko@google.com>, 2009
17 Andrew Borodin <aborodin@vmail.ru>, 2009
18 Ilia Maslakov <il.smind@gmail.com>, 2009
19
20 This file is part of the Midnight Commander.
21
22 The Midnight Commander is free software: you can redistribute it
23 and/or modify it under the terms of the GNU General Public License as
24 published by the Free Software Foundation, either version 3 of the License,
25 or (at your option) any later version.
26
27 The Midnight Commander is distributed in the hope that it will be useful,
28 but WITHOUT ANY WARRANTY; without even the implied warranty of
29 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
30 GNU General Public License for more details.
31
32 You should have received a copy of the GNU General Public License
33 along with this program. If not, see <http://www.gnu.org/licenses/>.
34 */
35
36 /*
37 The data source provides the viewer with data from either a file, a
38 string or the output of a command. The mcview_get_byte() function can be
39 used to get the value of a byte at a specific offset. If the offset
40 is out of range, -1 is returned. The function mcview_get_byte_indexed(a,b)
41 returns the byte at the offset a+b, or -1 if a+b is out of range.
42
43 The mcview_set_byte() function has the effect that later calls to
44 mcview_get_byte() will return the specified byte for this offset. This
45 function is designed only for use by the hexedit component after
46 saving its changes. Inspect the source before you want to use it for
47 other purposes.
48
49 The mcview_get_filesize() function returns the current size of the
50 data source. If the growing buffer is used, this size may increase
51 later on. Use the mcview_may_still_grow() function when you want to
52 know if the size can change later.
53 */
54
55 #include <config.h>
56
57 #include "lib/global.h"
58 #include "lib/vfs/vfs.h"
59 #include "lib/util.h"
60 #include "lib/widget.h" /* D_NORMAL, D_ERROR */
61
62 #include "internal.h"
63
64 /*** global variables ****************************************************************************/
65
66 /*** file scope macro definitions ****************************************************************/
67
68 /*** file scope type declarations ****************************************************************/
69
70 /*** file scope variables ************************************************************************/
71
72 /* --------------------------------------------------------------------------------------------- */
73 /*** file scope functions ************************************************************************/
74 /* --------------------------------------------------------------------------------------------- */
75
76 static void
mcview_set_datasource_stdio_pipe(WView * view,mc_pipe_t * p)77 mcview_set_datasource_stdio_pipe (WView * view, mc_pipe_t * p)
78 {
79 p->out.len = MC_PIPE_BUFSIZE;
80 p->out.null_term = FALSE;
81 p->err.len = MC_PIPE_BUFSIZE;
82 p->err.null_term = TRUE;
83 view->datasource = DS_STDIO_PIPE;
84 view->ds_stdio_pipe = p;
85 view->pipe_first_err_msg = TRUE;
86
87 mcview_growbuf_init (view);
88 }
89
90 /* --------------------------------------------------------------------------------------------- */
91 /*** public functions ****************************************************************************/
92 /* --------------------------------------------------------------------------------------------- */
93
94 void
mcview_set_datasource_none(WView * view)95 mcview_set_datasource_none (WView * view)
96 {
97 view->datasource = DS_NONE;
98 }
99
100 /* --------------------------------------------------------------------------------------------- */
101
102 off_t
mcview_get_filesize(WView * view)103 mcview_get_filesize (WView * view)
104 {
105 switch (view->datasource)
106 {
107 case DS_STDIO_PIPE:
108 case DS_VFS_PIPE:
109 return mcview_growbuf_filesize (view);
110 case DS_FILE:
111 return view->ds_file_filesize;
112 case DS_STRING:
113 return view->ds_string_len;
114 default:
115 return 0;
116 }
117 }
118
119 /* --------------------------------------------------------------------------------------------- */
120
121 void
mcview_update_filesize(WView * view)122 mcview_update_filesize (WView * view)
123 {
124 if (view->datasource == DS_FILE)
125 {
126 struct stat st;
127 if (mc_fstat (view->ds_file_fd, &st) != -1)
128 view->ds_file_filesize = st.st_size;
129 }
130 }
131
132 /* --------------------------------------------------------------------------------------------- */
133
134 char *
mcview_get_ptr_file(WView * view,off_t byte_index)135 mcview_get_ptr_file (WView * view, off_t byte_index)
136 {
137 g_assert (view->datasource == DS_FILE);
138
139 mcview_file_load_data (view, byte_index);
140 if (mcview_already_loaded (view->ds_file_offset, byte_index, view->ds_file_datalen))
141 return (char *) (view->ds_file_data + (byte_index - view->ds_file_offset));
142 return NULL;
143 }
144
145 /* --------------------------------------------------------------------------------------------- */
146
147 /* Invalid UTF-8 is reported as negative integers (one for each byte),
148 * see ticket 3783. */
149 gboolean
mcview_get_utf(WView * view,off_t byte_index,int * ch,int * ch_len)150 mcview_get_utf (WView * view, off_t byte_index, int *ch, int *ch_len)
151 {
152 gchar *str = NULL;
153 int res;
154 gchar utf8buf[UTF8_CHAR_LEN + 1];
155
156 switch (view->datasource)
157 {
158 case DS_STDIO_PIPE:
159 case DS_VFS_PIPE:
160 str = mcview_get_ptr_growing_buffer (view, byte_index);
161 break;
162 case DS_FILE:
163 str = mcview_get_ptr_file (view, byte_index);
164 break;
165 case DS_STRING:
166 str = mcview_get_ptr_string (view, byte_index);
167 break;
168 case DS_NONE:
169 default:
170 break;
171 }
172
173 *ch = 0;
174
175 if (str == NULL)
176 return FALSE;
177
178 res = g_utf8_get_char_validated (str, -1);
179
180 if (res < 0)
181 {
182 /* Retry with explicit bytes to make sure it's not a buffer boundary */
183 int i;
184
185 for (i = 0; i < UTF8_CHAR_LEN; i++)
186 {
187 if (mcview_get_byte (view, byte_index + i, &res))
188 utf8buf[i] = res;
189 else
190 {
191 utf8buf[i] = '\0';
192 break;
193 }
194 }
195 utf8buf[UTF8_CHAR_LEN] = '\0';
196 str = utf8buf;
197 res = g_utf8_get_char_validated (str, -1);
198 }
199
200 if (res < 0)
201 {
202 /* Implicit conversion from signed char to signed int keeps negative values. */
203 *ch = *str;
204 *ch_len = 1;
205 }
206 else
207 {
208 gchar *next_ch = NULL;
209
210 *ch = res;
211 /* Calculate UTF-8 char length */
212 next_ch = g_utf8_next_char (str);
213 *ch_len = next_ch - str;
214 }
215
216 return TRUE;
217 }
218
219 /* --------------------------------------------------------------------------------------------- */
220
221 char *
mcview_get_ptr_string(WView * view,off_t byte_index)222 mcview_get_ptr_string (WView * view, off_t byte_index)
223 {
224 g_assert (view->datasource == DS_STRING);
225
226 if (byte_index >= 0 && byte_index < (off_t) view->ds_string_len)
227 return (char *) (view->ds_string_data + byte_index);
228 return NULL;
229 }
230
231 /* --------------------------------------------------------------------------------------------- */
232
233 gboolean
mcview_get_byte_string(WView * view,off_t byte_index,int * retval)234 mcview_get_byte_string (WView * view, off_t byte_index, int *retval)
235 {
236 char *p;
237
238 if (retval != NULL)
239 *retval = -1;
240
241 p = mcview_get_ptr_string (view, byte_index);
242 if (p == NULL)
243 return FALSE;
244
245 if (retval != NULL)
246 *retval = (unsigned char) (*p);
247 return TRUE;
248 }
249
250 /* --------------------------------------------------------------------------------------------- */
251
252 gboolean
mcview_get_byte_none(WView * view,off_t byte_index,int * retval)253 mcview_get_byte_none (WView * view, off_t byte_index, int *retval)
254 {
255 (void) &view;
256 (void) byte_index;
257
258 g_assert (view->datasource == DS_NONE);
259
260 if (retval != NULL)
261 *retval = -1;
262 return FALSE;
263 }
264
265 /* --------------------------------------------------------------------------------------------- */
266
267 void
mcview_set_byte(WView * view,off_t offset,byte b)268 mcview_set_byte (WView * view, off_t offset, byte b)
269 {
270 (void) &b;
271
272 g_assert (offset < mcview_get_filesize (view));
273 g_assert (view->datasource == DS_FILE);
274
275 view->ds_file_datalen = 0; /* just force reloading */
276 }
277
278 /* --------------------------------------------------------------------------------------------- */
279
280 /*static */
281 void
mcview_file_load_data(WView * view,off_t byte_index)282 mcview_file_load_data (WView * view, off_t byte_index)
283 {
284 off_t blockoffset;
285 ssize_t res;
286 size_t bytes_read;
287
288 g_assert (view->datasource == DS_FILE);
289
290 if (mcview_already_loaded (view->ds_file_offset, byte_index, view->ds_file_datalen))
291 return;
292
293 if (byte_index >= view->ds_file_filesize)
294 return;
295
296 blockoffset = mcview_offset_rounddown (byte_index, view->ds_file_datasize);
297 if (mc_lseek (view->ds_file_fd, blockoffset, SEEK_SET) == -1)
298 goto error;
299
300 bytes_read = 0;
301 while (bytes_read < view->ds_file_datasize)
302 {
303 res =
304 mc_read (view->ds_file_fd, view->ds_file_data + bytes_read,
305 view->ds_file_datasize - bytes_read);
306 if (res == -1)
307 goto error;
308 if (res == 0)
309 break;
310 bytes_read += (size_t) res;
311 }
312 view->ds_file_offset = blockoffset;
313 if ((off_t) bytes_read > view->ds_file_filesize - view->ds_file_offset)
314 {
315 /* the file has grown in the meantime -- stick to the old size */
316 view->ds_file_datalen = view->ds_file_filesize - view->ds_file_offset;
317 }
318 else
319 {
320 view->ds_file_datalen = bytes_read;
321 }
322 return;
323
324 error:
325 view->ds_file_datalen = 0;
326 }
327
328 /* --------------------------------------------------------------------------------------------- */
329
330 void
mcview_close_datasource(WView * view)331 mcview_close_datasource (WView * view)
332 {
333 switch (view->datasource)
334 {
335 case DS_NONE:
336 break;
337 case DS_STDIO_PIPE:
338 if (view->ds_stdio_pipe != NULL)
339 {
340 mcview_growbuf_done (view);
341 mcview_display (view);
342 }
343 mcview_growbuf_free (view);
344 break;
345 case DS_VFS_PIPE:
346 if (view->ds_vfs_pipe != -1)
347 mcview_growbuf_done (view);
348 mcview_growbuf_free (view);
349 break;
350 case DS_FILE:
351 (void) mc_close (view->ds_file_fd);
352 view->ds_file_fd = -1;
353 MC_PTR_FREE (view->ds_file_data);
354 break;
355 case DS_STRING:
356 MC_PTR_FREE (view->ds_string_data);
357 break;
358 default:
359 break;
360 }
361 view->datasource = DS_NONE;
362 }
363
364 /* --------------------------------------------------------------------------------------------- */
365
366 void
mcview_set_datasource_file(WView * view,int fd,const struct stat * st)367 mcview_set_datasource_file (WView * view, int fd, const struct stat *st)
368 {
369 view->datasource = DS_FILE;
370 view->ds_file_fd = fd;
371 view->ds_file_filesize = st->st_size;
372 view->ds_file_offset = 0;
373 view->ds_file_data = g_malloc (4096);
374 view->ds_file_datalen = 0;
375 view->ds_file_datasize = 4096;
376 }
377
378 /* --------------------------------------------------------------------------------------------- */
379
380 gboolean
mcview_load_command_output(WView * view,const char * command)381 mcview_load_command_output (WView * view, const char *command)
382 {
383 mc_pipe_t *p;
384 GError *error = NULL;
385
386 mcview_close_datasource (view);
387
388 p = mc_popen (command, TRUE, TRUE, &error);
389 if (p == NULL)
390 {
391 mcview_display (view);
392 mcview_show_error (view, error->message);
393 g_error_free (error);
394 return FALSE;
395 }
396
397 /* Check if filter produced any output */
398 mcview_set_datasource_stdio_pipe (view, p);
399 if (!mcview_get_byte (view, 0, NULL))
400 {
401 mcview_close_datasource (view);
402 mcview_display (view);
403 return FALSE;
404 }
405
406 return TRUE;
407 }
408
409 /* --------------------------------------------------------------------------------------------- */
410
411 void
mcview_set_datasource_vfs_pipe(WView * view,int fd)412 mcview_set_datasource_vfs_pipe (WView * view, int fd)
413 {
414 g_assert (fd != -1);
415
416 view->datasource = DS_VFS_PIPE;
417 view->ds_vfs_pipe = fd;
418
419 mcview_growbuf_init (view);
420 }
421
422 /* --------------------------------------------------------------------------------------------- */
423
424 void
mcview_set_datasource_string(WView * view,const char * s)425 mcview_set_datasource_string (WView * view, const char *s)
426 {
427 view->datasource = DS_STRING;
428 view->ds_string_len = strlen (s);
429 view->ds_string_data = (byte *) g_strndup (s, view->ds_string_len);
430 }
431
432 /* --------------------------------------------------------------------------------------------- */
433