source: mainline/uspace/app/bdsh/cmds/modules/cat/cat.c

Last change on this file was 87822ce, checked in by Jiri Svoboda <jiri@…>, 4 years ago

Avoid infinite loop when console communication is broken

Need to make sure callers of console_get_event_timeout() can distinguish
between timeout and I/O error. Fix all callers of console_get_event()
and console_get_event_timeout() not to enter infinite loop when console
connection is broken. Also avoid setting of errno variable.
  • Property mode set to 100644
File size: 10.1 KB
Line 
1/*
2 * Copyright (c) 2008 Tim Post
3 * Copyright (c) 2011, Martin Sucha
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * - Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * - Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * - The name of the author may not be used to endorse or promote products
16 * derived from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30#include <stdio.h>
31#include <stdlib.h>
32#include <getopt.h>
33#include <str.h>
34#include <io/console.h>
35#include <io/color.h>
36#include <io/style.h>
37#include <io/keycode.h>
38#include <errno.h>
39#include <vfs/vfs.h>
40#include <assert.h>
41
42#include "config.h"
43#include "util.h"
44#include "errors.h"
45#include "entry.h"
46#include "cat.h"
47#include "cmds.h"
48
49static const char *cmdname = "cat";
50#define CAT_VERSION "0.0.1"
51#define CAT_DEFAULT_BUFLEN 1024
52#define CAT_FULL_FILE 0
53
54static const char *hexchars = "0123456789abcdef";
55
56static bool paging_enabled = false;
57static size_t chars_remaining = 0;
58static size_t lines_remaining = 0;
59static sysarg_t console_cols = 0;
60static sysarg_t console_rows = 0;
61static bool should_quit = false;
62static bool dash_represents_stdin = false;
63static unsigned int lineno = 0;
64static bool number = false;
65static bool last_char_was_newline = false;
66
67static console_ctrl_t *console = NULL;
68
69static struct option const long_options[] = {
70 { "help", no_argument, 0, 'h' },
71 { "version", no_argument, 0, 'v' },
72 { "head", required_argument, 0, 'H' },
73 { "tail", required_argument, 0, 't' },
74 { "buffer", required_argument, 0, 'b' },
75 { "more", no_argument, 0, 'm' },
76 { "hex", no_argument, 0, 'x' },
77 { "stdin", no_argument, 0, 's' },
78 { "number", no_argument, 0, 'n' },
79 { 0, 0, 0, 0 }
80};
81
82/* Dispays help for cat in various levels */
83void help_cmd_cat(unsigned int level)
84{
85 if (level == HELP_SHORT) {
86 printf("`%s' shows the contents of files\n", cmdname);
87 } else {
88 help_cmd_cat(HELP_SHORT);
89 printf(
90 "Usage: %s [options] <file1> [file2] [...]\n"
91 "Options:\n"
92 " -h, --help A short option summary\n"
93 " -v, --version Print version information and exit\n"
94 " -H, --head ## Print only the first ## bytes\n"
95 " -t, --tail ## Print only the last ## bytes\n"
96 " -b, --buffer ## Set the read buffer size to ##\n"
97 " -m, --more Pause after each screen full\n"
98 " -x, --hex Print bytes as hex values\n"
99 " -s, --stdin Treat `-' in file list as standard input\n"
100 " -n, --number Number all output lines\n"
101 "Currently, %s is under development, some options don't work.\n",
102 cmdname, cmdname);
103 }
104
105 return;
106}
107
108static void waitprompt(void)
109{
110 console_set_pos(console, 0, console_rows - 1);
111 console_set_color(console, COLOR_WHITE, COLOR_BLUE, 0);
112
113 printf("ENTER/SPACE/PAGE DOWN - next page, "
114 "ESC/Q - quit, C - continue unpaged");
115 fflush(stdout);
116
117 console_set_style(console, STYLE_NORMAL);
118}
119
120static void waitkey(void)
121{
122 cons_event_t ev;
123 kbd_event_t *kev;
124 errno_t rc;
125
126 while (true) {
127 rc = console_get_event(console, &ev);
128 if (rc != EOK)
129 return;
130 if (ev.type == CEV_KEY && ev.ev.key.type == KEY_PRESS) {
131 kev = &ev.ev.key;
132
133 if (kev->key == KC_ESCAPE || kev->key == KC_Q) {
134 should_quit = true;
135 return;
136 }
137 if (kev->key == KC_C) {
138 paging_enabled = false;
139 return;
140 }
141 if (kev->key == KC_ENTER || kev->key == KC_SPACE ||
142 kev->key == KC_PAGE_DOWN) {
143 return;
144 }
145 }
146 }
147 assert(false);
148}
149
150static void newpage(void)
151{
152 console_clear(console);
153 chars_remaining = console_cols;
154 lines_remaining = console_rows - 1;
155}
156
157static void paged_char(char32_t c)
158{
159 if (last_char_was_newline && number) {
160 lineno++;
161 printf("%6u ", lineno);
162 }
163 putuchar(c);
164 last_char_was_newline = c == '\n';
165 if (paging_enabled) {
166 chars_remaining--;
167 if (c == '\n' || chars_remaining == 0) {
168 chars_remaining = console_cols;
169 lines_remaining--;
170 }
171 if (lines_remaining == 0) {
172 fflush(stdout);
173 waitprompt();
174 waitkey();
175 newpage();
176 }
177 }
178}
179
180static unsigned int cat_file(const char *fname, size_t blen, bool hex,
181 off64_t head, off64_t tail, bool tail_first)
182{
183 int fd, count = 0, reads = 0;
184 size_t bytes;
185 char *buff = NULL;
186 size_t i;
187 size_t offset = 0, copied_bytes = 0;
188 off64_t file_size = 0, length = 0;
189 aoff64_t pos = 0;
190 errno_t rc;
191
192 bool reading_stdin = dash_represents_stdin && (str_cmp(fname, "-") == 0);
193
194 if (reading_stdin) {
195 fd = fileno(stdin);
196 /* Allow storing the whole UTF-8 character. */
197 blen = STR_BOUNDS(1);
198 } else {
199 errno_t rc = vfs_lookup_open(fname, WALK_REGULAR, MODE_READ, &fd);
200 if (rc != EOK) {
201 fd = -1;
202 }
203 }
204
205 if (fd < 0) {
206 printf("Unable to open %s\n", fname);
207 return 1;
208 }
209
210 if (NULL == (buff = (char *) malloc(blen + 1))) {
211 vfs_put(fd);
212 printf("Unable to allocate enough memory to read %s\n",
213 fname);
214 return 1;
215 }
216
217 if (tail != CAT_FULL_FILE) {
218 vfs_stat_t st;
219
220 if (vfs_stat(fd, &st) != EOK) {
221 vfs_put(fd);
222 free(buff);
223 printf("Unable to vfs_stat %d\n", fd);
224 return 1;
225 }
226 file_size = st.size;
227 if (head == CAT_FULL_FILE) {
228 head = file_size;
229 length = tail;
230 } else if (tail_first) {
231 length = head;
232 } else {
233 if (tail > head)
234 tail = head;
235 length = tail;
236 }
237
238 if (tail_first) {
239 pos = (tail >= file_size) ? 0 : (file_size - tail);
240 } else {
241 pos = ((head - tail) >= file_size) ? 0 : (head - tail);
242 }
243 } else
244 length = head;
245
246 do {
247 size_t bytes_to_read;
248 if (reading_stdin) {
249 bytes_to_read = 1;
250 } else {
251 if ((length != CAT_FULL_FILE) &&
252 (length - (off64_t)count <= (off64_t)(blen - copied_bytes))) {
253 bytes_to_read = (size_t) (length - count);
254 } else {
255 bytes_to_read = blen - copied_bytes;
256 }
257 }
258
259 rc = vfs_read(fd, &pos, buff + copied_bytes, bytes_to_read,
260 &bytes);
261 copied_bytes = 0;
262
263 if (rc == EOK && bytes > 0) {
264 buff[bytes] = '\0';
265 offset = 0;
266 for (i = 0; i < bytes && !should_quit; i++) {
267 if (hex) {
268 paged_char(hexchars[((uint8_t)buff[i]) / 16]);
269 paged_char(hexchars[((uint8_t)buff[i]) % 16]);
270 paged_char(((count + i + 1) & 0xf) == 0 ? '\n' : ' ');
271 } else {
272 char32_t c = str_decode(buff, &offset, bytes);
273 if (c == 0) {
274 /* Reached end of string */
275 break;
276 } else if (c == U_SPECIAL && offset + 2 >= (size_t)bytes) {
277 /*
278 * If an extended character is cut off due to the size of the buffer,
279 * we will copy it over to the next buffer so it can be read correctly.
280 */
281 copied_bytes = bytes - offset + 1;
282 memcpy(buff, buff + offset - 1, copied_bytes);
283 break;
284 }
285 paged_char(c);
286 }
287
288 }
289 count += bytes;
290 reads++;
291 }
292
293 if (reading_stdin)
294 fflush(stdout);
295 } while (rc == EOK && bytes > 0 && !should_quit && (count < length || length == CAT_FULL_FILE));
296
297 vfs_put(fd);
298 if (rc != EOK) {
299 printf("Error reading %s\n", fname);
300 free(buff);
301 return 1;
302 }
303
304 free(buff);
305
306 return 0;
307}
308
309/* Main entry point for cat, accepts an array of arguments */
310int cmd_cat(char **argv)
311{
312 unsigned int argc, i, ret = 0;
313 size_t buffer = 0;
314 int c, opt_ind;
315 aoff64_t head = CAT_FULL_FILE, tail = CAT_FULL_FILE;
316 bool hex = false;
317 bool more = false;
318 bool tailFirst = false;
319 sysarg_t rows, cols;
320 errno_t rc;
321
322 /*
323 * reset global state
324 * TODO: move to structure?
325 */
326 paging_enabled = false;
327 chars_remaining = 0;
328 lines_remaining = 0;
329 console_cols = 0;
330 console_rows = 0;
331 should_quit = false;
332 dash_represents_stdin = false;
333 console = console_init(stdin, stdout);
334 number = false;
335 lineno = 0;
336 /* This enables printing of the first number. */
337 last_char_was_newline = true;
338
339 argc = cli_count_args(argv);
340
341 c = 0;
342 optreset = 1;
343 optind = 0;
344 opt_ind = 0;
345
346 while (c != -1) {
347 c = getopt_long(argc, argv, "xhvmH:t:b:sn", long_options, &opt_ind);
348 switch (c) {
349 case 'h':
350 help_cmd_cat(HELP_LONG);
351 return CMD_SUCCESS;
352 case 'v':
353 printf("%s\n", CAT_VERSION);
354 return CMD_SUCCESS;
355 case 'H':
356 if (!optarg || str_uint64_t(optarg, NULL, 10, false, &head) != EOK) {
357 puts("Invalid head size");
358 return CMD_FAILURE;
359 }
360 break;
361 case 't':
362 if (!optarg || str_uint64_t(optarg, NULL, 10, false, &tail) != EOK) {
363 puts("Invalid tail size");
364 return CMD_FAILURE;
365 }
366 if (head == CAT_FULL_FILE)
367 tailFirst = true;
368 break;
369 case 'b':
370 if (!optarg || str_size_t(optarg, NULL, 10, false, &buffer) != EOK) {
371 puts("Invalid buffer size");
372 return CMD_FAILURE;
373 }
374 break;
375 case 'm':
376 more = true;
377 break;
378 case 'x':
379 hex = true;
380 break;
381 case 's':
382 dash_represents_stdin = true;
383 break;
384 case 'n':
385 number = true;
386 break;
387 }
388 }
389
390 argc -= optind;
391
392 if (argc < 1) {
393 printf("%s - incorrect number of arguments. Try `%s --help'\n",
394 cmdname, cmdname);
395 return CMD_FAILURE;
396 }
397
398 if (buffer < 4)
399 buffer = CAT_DEFAULT_BUFLEN;
400
401 if (more) {
402 rc = console_get_size(console, &cols, &rows);
403 if (rc != EOK) {
404 printf("%s - cannot get console size\n", cmdname);
405 return CMD_FAILURE;
406 }
407 console_cols = cols;
408 console_rows = rows;
409 paging_enabled = true;
410 newpage();
411 }
412
413 for (i = optind; argv[i] != NULL && !should_quit; i++)
414 ret += cat_file(argv[i], buffer, hex, head, tail, tailFirst);
415
416 if (ret)
417 return CMD_FAILURE;
418 else
419 return CMD_SUCCESS;
420}
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