1 ///////////////////////////////////////////////////////////////////////////////
2 //
3 /// \file main.c
4 /// \brief main()
5 //
6 // Author: Lasse Collin
7 //
8 // This file has been put into the public domain.
9 // You can do whatever you want with this file.
10 //
11 ///////////////////////////////////////////////////////////////////////////////
12
13 #include "private.h"
14 #include <ctype.h>
15
16 /// Exit status to use. This can be changed with set_exit_status().
17 static enum exit_status_type exit_status = E_SUCCESS;
18
19 #if defined(_WIN32) && !defined(__CYGWIN__)
20 /// exit_status has to be protected with a critical section due to
21 /// how "signal handling" is done on Windows. See signals.c for details.
22 static CRITICAL_SECTION exit_status_cs;
23 #endif
24
25 /// True if --no-warn is specified. When this is true, we don't set
26 /// the exit status to E_WARNING when something worth a warning happens.
27 static bool no_warn = false;
28
29
30 extern void
set_exit_status(enum exit_status_type new_status)31 set_exit_status(enum exit_status_type new_status)
32 {
33 assert(new_status == E_WARNING || new_status == E_ERROR);
34
35 #if defined(_WIN32) && !defined(__CYGWIN__)
36 EnterCriticalSection(&exit_status_cs);
37 #endif
38
39 if (exit_status != E_ERROR)
40 exit_status = new_status;
41
42 #if defined(_WIN32) && !defined(__CYGWIN__)
43 LeaveCriticalSection(&exit_status_cs);
44 #endif
45
46 return;
47 }
48
49
50 extern void
set_exit_no_warn(void)51 set_exit_no_warn(void)
52 {
53 no_warn = true;
54 return;
55 }
56
57
58 static const char *
read_name(const args_info * args)59 read_name(const args_info *args)
60 {
61 // FIXME: Maybe we should have some kind of memory usage limit here
62 // like the tool has for the actual compression and decompression.
63 // Giving some huge text file with --files0 makes us to read the
64 // whole file in RAM.
65 static char *name = NULL;
66 static size_t size = 256;
67
68 // Allocate the initial buffer. This is never freed, since after it
69 // is no longer needed, the program exits very soon. It is safe to
70 // use xmalloc() and xrealloc() in this function, because while
71 // executing this function, no files are open for writing, and thus
72 // there's no need to cleanup anything before exiting.
73 if (name == NULL)
74 name = xmalloc(size);
75
76 // Write position in name
77 size_t pos = 0;
78
79 // Read one character at a time into name.
80 while (!user_abort) {
81 const int c = fgetc(args->files_file);
82
83 if (ferror(args->files_file)) {
84 // Take care of EINTR since we have established
85 // the signal handlers already.
86 if (errno == EINTR)
87 continue;
88
89 message_error(_("%s: Error reading filenames: %s"),
90 args->files_name, strerror(errno));
91 return NULL;
92 }
93
94 if (feof(args->files_file)) {
95 if (pos != 0)
96 message_error(_("%s: Unexpected end of input "
97 "when reading filenames"),
98 args->files_name);
99
100 return NULL;
101 }
102
103 if (c == args->files_delim) {
104 // We allow consecutive newline (--files) or '\0'
105 // characters (--files0), and ignore such empty
106 // filenames.
107 if (pos == 0)
108 continue;
109
110 // A non-empty name was read. Terminate it with '\0'
111 // and return it.
112 name[pos] = '\0';
113 return name;
114 }
115
116 if (c == '\0') {
117 // A null character was found when using --files,
118 // which expects plain text input separated with
119 // newlines.
120 message_error(_("%s: Null character found when "
121 "reading filenames; maybe you meant "
122 "to use `--files0' instead "
123 "of `--files'?"), args->files_name);
124 return NULL;
125 }
126
127 name[pos++] = c;
128
129 // Allocate more memory if needed. There must always be space
130 // at least for one character to allow terminating the string
131 // with '\0'.
132 if (pos == size) {
133 size *= 2;
134 name = xrealloc(name, size);
135 }
136 }
137
138 return NULL;
139 }
140
141
142 int
main(int argc,char ** argv)143 main(int argc, char **argv)
144 {
145 #if defined(_WIN32) && !defined(__CYGWIN__)
146 InitializeCriticalSection(&exit_status_cs);
147 #endif
148
149 // Set up the progname variable.
150 tuklib_progname_init(argv);
151
152 // Initialize the file I/O. This makes sure that
153 // stdin, stdout, and stderr are something valid.
154 io_init();
155
156 // Set up the locale and message translations.
157 tuklib_gettext_init(PACKAGE, LOCALEDIR);
158
159 // Initialize handling of error/warning/other messages.
160 message_init();
161
162 // Set hardware-dependent default values. These can be overridden
163 // on the command line, thus this must be done before args_parse().
164 hardware_init();
165
166 // Parse the command line arguments and get an array of filenames.
167 // This doesn't return if something is wrong with the command line
168 // arguments. If there are no arguments, one filename ("-") is still
169 // returned to indicate stdin.
170 args_info args;
171 args_parse(&args, argc, argv);
172
173 if (opt_mode != MODE_LIST && opt_robot)
174 message_fatal(_("Compression and decompression with --robot "
175 "are not supported yet."));
176
177 // Tell the message handling code how many input files there are if
178 // we know it. This way the progress indicator can show it.
179 if (args.files_name != NULL)
180 message_set_files(0);
181 else
182 message_set_files(args.arg_count);
183
184 // Refuse to write compressed data to standard output if it is
185 // a terminal.
186 if (opt_mode == MODE_COMPRESS) {
187 if (opt_stdout || (args.arg_count == 1
188 && strcmp(args.arg_names[0], "-") == 0)) {
189 if (is_tty_stdout()) {
190 message_try_help();
191 tuklib_exit(E_ERROR, E_ERROR, false);
192 }
193 }
194 }
195
196 // Set up the signal handlers. We don't need these before we
197 // start the actual action and not in --list mode, so this is
198 // done after parsing the command line arguments.
199 //
200 // It's good to keep signal handlers in normal compression and
201 // decompression modes even when only writing to stdout, because
202 // we might need to restore O_APPEND flag on stdout before exiting.
203 // In --test mode, signal handlers aren't really needed, but let's
204 // keep them there for consistency with normal decompression.
205 if (opt_mode != MODE_LIST)
206 signals_init();
207
208 #ifdef ENABLE_SANDBOX
209 // Set a flag that sandboxing is allowed if all these are true:
210 // - --files or --files0 wasn't used.
211 // - There is exactly one input file or we are reading from stdin.
212 // - We won't create any files: output goes to stdout or --test
213 // or --list was used. Note that --test implies opt_stdout = true
214 // but --list doesn't.
215 //
216 // This is obviously not ideal but it was easy to implement and
217 // it covers the most common use cases.
218 //
219 // TODO: Make sandboxing work for other situations too.
220 if (args.files_name == NULL && args.arg_count == 1
221 && (opt_stdout || strcmp("-", args.arg_names[0]) == 0
222 || opt_mode == MODE_LIST))
223 io_allow_sandbox();
224 #endif
225
226 // coder_run() handles compression, decompression, and testing.
227 // list_file() is for --list.
228 void (*run)(const char *filename) = &coder_run;
229 #ifdef HAVE_DECODERS
230 if (opt_mode == MODE_LIST)
231 run = &list_file;
232 #endif
233
234 // Process the files given on the command line. Note that if no names
235 // were given, args_parse() gave us a fake "-" filename.
236 for (unsigned i = 0; i < args.arg_count && !user_abort; ++i) {
237 if (strcmp("-", args.arg_names[i]) == 0) {
238 // Processing from stdin to stdout. Check that we
239 // aren't writing compressed data to a terminal or
240 // reading it from a terminal.
241 if (opt_mode == MODE_COMPRESS) {
242 if (is_tty_stdout())
243 continue;
244 } else if (is_tty_stdin()) {
245 continue;
246 }
247
248 // It doesn't make sense to compress data from stdin
249 // if we are supposed to read filenames from stdin
250 // too (enabled with --files or --files0).
251 if (args.files_name == stdin_filename) {
252 message_error(_("Cannot read data from "
253 "standard input when "
254 "reading filenames "
255 "from standard input"));
256 continue;
257 }
258
259 // Replace the "-" with a special pointer, which is
260 // recognized by coder_run() and other things.
261 // This way error messages get a proper filename
262 // string and the code still knows that it is
263 // handling the special case of stdin.
264 args.arg_names[i] = (char *)stdin_filename;
265 }
266
267 // Do the actual compression or decompression.
268 run(args.arg_names[i]);
269 }
270
271 // If --files or --files0 was used, process the filenames from the
272 // given file or stdin. Note that here we don't consider "-" to
273 // indicate stdin like we do with the command line arguments.
274 if (args.files_name != NULL) {
275 // read_name() checks for user_abort so we don't need to
276 // check it as loop termination condition.
277 while (true) {
278 const char *name = read_name(&args);
279 if (name == NULL)
280 break;
281
282 // read_name() doesn't return empty names.
283 assert(name[0] != '\0');
284 run(name);
285 }
286
287 if (args.files_name != stdin_filename)
288 (void)fclose(args.files_file);
289 }
290
291 #ifdef HAVE_DECODERS
292 // All files have now been handled. If in --list mode, display
293 // the totals before exiting. We don't have signal handlers
294 // enabled in --list mode, so we don't need to check user_abort.
295 if (opt_mode == MODE_LIST) {
296 assert(!user_abort);
297 list_totals();
298 }
299 #endif
300
301 #ifndef NDEBUG
302 coder_free();
303 args_free();
304 #endif
305
306 // If we have got a signal, raise it to kill the program instead
307 // of calling tuklib_exit().
308 signals_exit();
309
310 // Make a local copy of exit_status to keep the Windows code
311 // thread safe. At this point it is fine if we miss the user
312 // pressing C-c and don't set the exit_status to E_ERROR on
313 // Windows.
314 #if defined(_WIN32) && !defined(__CYGWIN__)
315 EnterCriticalSection(&exit_status_cs);
316 #endif
317
318 enum exit_status_type es = exit_status;
319
320 #if defined(_WIN32) && !defined(__CYGWIN__)
321 LeaveCriticalSection(&exit_status_cs);
322 #endif
323
324 // Suppress the exit status indicating a warning if --no-warn
325 // was specified.
326 if (es == E_WARNING && no_warn)
327 es = E_SUCCESS;
328
329 tuklib_exit((int)es, E_ERROR, message_verbosity_get() != V_SILENT);
330 }
331