2 Internal file viewer for the Midnight Commander
3 Functions for datasources
5 Copyright (C) 1994, 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2003,
6 2004, 2005, 2006, 2007, 2009 Free Software Foundation, Inc.
8 Written by: 1994, 1995, 1998 Miguel de Icaza
9 1994, 1995 Janne Kukonlehto
14 2004 Roland Illig <roland.illig@gmx.de>
15 2005 Roland Illig <roland.illig@gmx.de>
16 2009 Slava Zanko <slavazanko@google.com>
17 2009 Andrew Borodin <aborodin@vmail.ru>
18 2009 Ilia Maslakov <il.smind@gmail.com>
20 This file is part of the Midnight Commander.
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 2 of the
25 License, or (at your option) any later version.
27 The Midnight Commander is distributed in the hope that it will be
28 useful, but WITHOUT ANY WARRANTY; without even the implied warranty
29 of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
30 General Public License for more details.
32 You should have received a copy of the GNU General Public License
33 along with this program; if not, write to the Free Software
34 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
39 The data source provides the viewer with data from either a file, a
40 string or the output of a command. The mcview_get_byte() function can be
41 used to get the value of a byte at a specific offset. If the offset
42 is out of range, -1 is returned. The function mcview_get_byte_indexed(a,b)
43 returns the byte at the offset a+b, or -1 if a+b is out of range.
45 The mcview_set_byte() function has the effect that later calls to
46 mcview_get_byte() will return the specified byte for this offset. This
47 function is designed only for use by the hexedit component after
48 saving its changes. Inspect the source before you want to use it for
51 The mcview_get_filesize() function returns the current size of the
52 data source. If the growing buffer is used, this size may increase
53 later on. Use the mcview_may_still_grow() function when you want to
54 know if the size can change later.
59 #include "../src/global.h"
60 #include "../src/wtools.h"
63 /*** global variables ****************************************************************************/
65 /*** file scope macro definitions ****************************************************************/
67 /*** file scope type declarations ****************************************************************/
69 /*** file scope variables ************************************************************************/
71 /*** file scope functions ************************************************************************/
73 /*** public functions ****************************************************************************/
75 /* --------------------------------------------------------------------------------------------- */
78 mcview_set_datasource_stdio_pipe (mcview_t
* view
, FILE * fp
)
81 view
->datasource
= DS_STDIO_PIPE
;
82 view
->ds_stdio_pipe
= fp
;
84 mcview_growbuf_init (view
);
87 /* --------------------------------------------------------------------------------------------- */
90 mcview_set_datasource_none (mcview_t
* view
)
92 view
->datasource
= DS_NONE
;
95 /* --------------------------------------------------------------------------------------------- */
98 mcview_get_filesize (mcview_t
* view
)
100 switch (view
->datasource
) {
105 return mcview_growbuf_filesize (view
);
107 return view
->ds_file_filesize
;
109 return view
->ds_string_len
;
111 assert (!"Unknown datasource type");
116 /* --------------------------------------------------------------------------------------------- */
119 mcview_get_ptr_file (mcview_t
* view
, off_t byte_index
)
121 assert (view
->datasource
== DS_FILE
);
123 mcview_file_load_data (view
, byte_index
);
124 if (mcview_already_loaded (view
->ds_file_offset
, byte_index
, view
->ds_file_datalen
))
125 return (char *) (view
->ds_file_data
+ (byte_index
- view
->ds_file_offset
));
129 /* --------------------------------------------------------------------------------------------- */
132 mcview_get_ptr_string (mcview_t
* view
, off_t byte_index
)
134 assert (view
->datasource
== DS_STRING
);
135 if (byte_index
< view
->ds_string_len
)
136 return (char *) (view
->ds_string_data
+ byte_index
);
140 /* --------------------------------------------------------------------------------------------- */
143 mcview_get_utf (mcview_t
* view
, off_t byte_index
, int *char_width
, gboolean
* result
)
148 gchar
*next_ch
= NULL
;
153 switch (view
->datasource
) {
156 str
= mcview_get_ptr_growing_buffer (view
, byte_index
);
159 str
= mcview_get_ptr_file (view
, byte_index
);
162 str
= mcview_get_ptr_string (view
, byte_index
);
174 res
= g_utf8_get_char_validated (str
, -1);
181 /* Calculate UTF-8 char width */
182 next_ch
= g_utf8_next_char (str
);
184 width
= next_ch
- str
;
194 /* --------------------------------------------------------------------------------------------- */
197 mcview_get_byte_string (mcview_t
* view
, off_t byte_index
, int *retval
)
199 assert (view
->datasource
== DS_STRING
);
200 if (byte_index
< view
->ds_string_len
) {
202 *retval
= view
->ds_string_data
[byte_index
];
210 /* --------------------------------------------------------------------------------------------- */
213 mcview_get_byte_none (mcview_t
* view
, off_t byte_index
, int *retval
)
215 assert (view
->datasource
== DS_NONE
);
223 /* --------------------------------------------------------------------------------------------- */
226 mcview_set_byte (mcview_t
* view
, off_t offset
, byte b
)
229 assert (offset
< mcview_get_filesize (view
));
230 assert (view
->datasource
== DS_FILE
);
231 view
->ds_file_datalen
= 0; /* just force reloading */
234 /* --------------------------------------------------------------------------------------------- */
238 mcview_file_load_data (mcview_t
* view
, off_t byte_index
)
244 assert (view
->datasource
== DS_FILE
);
246 if (mcview_already_loaded (view
->ds_file_offset
, byte_index
, view
->ds_file_datalen
))
249 if (byte_index
>= view
->ds_file_filesize
)
252 blockoffset
= mcview_offset_rounddown (byte_index
, view
->ds_file_datasize
);
253 if (mc_lseek (view
->ds_file_fd
, blockoffset
, SEEK_SET
) == -1)
257 while (bytes_read
< view
->ds_file_datasize
) {
259 mc_read (view
->ds_file_fd
, view
->ds_file_data
+ bytes_read
,
260 view
->ds_file_datasize
- bytes_read
);
265 bytes_read
+= (size_t) res
;
267 view
->ds_file_offset
= blockoffset
;
268 if (bytes_read
> view
->ds_file_filesize
- view
->ds_file_offset
) {
269 /* the file has grown in the meantime -- stick to the old size */
270 view
->ds_file_datalen
= view
->ds_file_filesize
- view
->ds_file_offset
;
272 view
->ds_file_datalen
= bytes_read
;
277 view
->ds_file_datalen
= 0;
280 /* --------------------------------------------------------------------------------------------- */
283 mcview_close_datasource (mcview_t
* view
)
285 switch (view
->datasource
) {
289 if (view
->ds_stdio_pipe
!= NULL
) {
290 (void) pclose (view
->ds_stdio_pipe
);
291 mcview_display (view
);
292 close_error_pipe (D_NORMAL
, NULL
);
293 view
->ds_stdio_pipe
= NULL
;
295 mcview_growbuf_free (view
);
298 if (view
->ds_vfs_pipe
!= -1) {
299 (void) mc_close (view
->ds_vfs_pipe
);
300 view
->ds_vfs_pipe
= -1;
302 mcview_growbuf_free (view
);
305 (void) mc_close (view
->ds_file_fd
);
306 view
->ds_file_fd
= -1;
307 g_free (view
->ds_file_data
);
308 view
->ds_file_data
= NULL
;
311 g_free (view
->ds_string_data
);
312 view
->ds_string_data
= NULL
;
315 assert (!"Unknown datasource type");
317 view
->datasource
= DS_NONE
;
320 /* --------------------------------------------------------------------------------------------- */
323 mcview_set_datasource_file (mcview_t
* view
, int fd
, const struct stat
*st
)
325 view
->datasource
= DS_FILE
;
326 view
->ds_file_fd
= fd
;
327 view
->ds_file_filesize
= st
->st_size
;
328 view
->ds_file_offset
= 0;
329 view
->ds_file_data
= g_malloc (4096);
330 view
->ds_file_datalen
= 0;
331 view
->ds_file_datasize
= 4096;
334 /* --------------------------------------------------------------------------------------------- */
337 mcview_load_command_output (mcview_t
* view
, const char *command
)
341 mcview_close_datasource (view
);
344 if ((fp
= popen (command
, "r")) == NULL
) {
345 /* Avoid two messages. Message from stderr has priority. */
346 mcview_display (view
);
347 if (!close_error_pipe (mcview_is_in_panel (view
) ? -1 : D_ERROR
, NULL
))
348 mcview_show_error (view
, _(" Cannot spawn child process "));
352 /* First, check if filter produced any output */
353 mcview_set_datasource_stdio_pipe (view
, fp
);
354 if (! mcview_get_byte (view
, 0, NULL
)) {
355 mcview_close_datasource (view
);
357 /* Avoid two messages. Message from stderr has priority. */
358 mcview_display (view
);
359 if (!close_error_pipe (mcview_is_in_panel (view
) ? -1 : D_ERROR
, NULL
))
360 mcview_show_error (view
, _("Empty output from child filter"));
364 * At least something was read correctly. Close stderr and let
365 * program die if it will try to write something there.
367 * Ideally stderr should be read asynchronously to prevent programs
368 * from blocking (poll/select multiplexor).
370 close_error_pipe (D_NORMAL
, NULL
);
375 /* --------------------------------------------------------------------------------------------- */
378 mcview_set_datasource_vfs_pipe (mcview_t
* view
, int fd
)
381 view
->datasource
= DS_VFS_PIPE
;
382 view
->ds_vfs_pipe
= fd
;
384 mcview_growbuf_init (view
);
387 /* --------------------------------------------------------------------------------------------- */
390 mcview_set_datasource_string (mcview_t
* view
, const char *s
)
392 view
->datasource
= DS_STRING
;
393 view
->ds_string_data
= (byte
*) g_strdup (s
);
394 view
->ds_string_len
= strlen (s
);
397 /* --------------------------------------------------------------------------------------------- */