2 Copyright (C) 1998, 2000, 2001 Free Software Foundation, Inc.
4 This file is part of GNU Wget.
6 GNU Wget is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 GNU Wget 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
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with Wget; if not, write to the Free Software
18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 In addition, as a special exception, the Free Software Foundation
21 gives permission to link the code of its release of Wget with the
22 OpenSSL project's "OpenSSL" library (or with modified versions of it
23 that use the same license as the "OpenSSL" library), and distribute
24 the linked executables. You must obey the GNU General Public License
25 in all respects for all of the code used other than "OpenSSL". If you
26 modify this file, you may extend this exception to your version of the
27 file, but you are not obligated to do so. If you do not wish to do
28 so, delete this exception statement from your version. */
32 /* This allows the architecture-specific .h files to specify the use
33 of stdargs regardless of __STDC__. */
34 #ifndef WGET_USE_STDARG
35 /* Use stdarg only if the compiler supports ANSI C and stdarg.h is
36 present. We check for both because there are configurations where
37 stdarg.h exists, but doesn't work. */
40 # define WGET_USE_STDARG
43 #endif /* not WGET_USE_STDARG */
52 #ifdef WGET_USE_STDARG
70 /* This file impplement support for "logging". Logging means printing
71 output, plus several additional features:
73 - Cataloguing output by importance. You can specify that a log
74 message is "verbose" or "debug", and it will not be printed unless
75 in verbose or debug mode, respectively.
77 - Redirecting the log to the file. When Wget's output goes to the
78 terminal, and Wget receives SIGHUP, all further output is
79 redirected to a log file. When this is the case, Wget can also
80 print the last several lines of "context" to the log file so that
81 it does not begin in the middle of a line. For this to work, the
82 logging code stores the last several lines of context. Callers may
83 request for certain output not to be stored.
85 - Inhibiting output. When Wget receives SIGHUP, but redirecting
86 the output fails, logging is inhibited. */
89 /* The file descriptor used for logging. This is NULL before log_init
90 is called; logging functions log to stderr then. log_init sets it
91 either to stderr or to a file pointer obtained from fopen(). If
92 logging is inhibited, logfp is set back to NULL. */
95 /* If non-zero, it means logging is inhibited, i.e. nothing is printed
97 static int inhibit_logging;
99 /* Whether the last output lines are stored for use as context. */
100 static int save_context_p;
102 /* Whether the log is flushed after each command. */
103 static int flush_log_p = 1;
105 /* Whether any output has been received while flush_log_p was 0. */
106 static int needs_flushing;
108 /* In the event of a hang-up, and if its output was on a TTY, Wget
109 redirects its output to `wget-log'.
111 For the convenience of reading this newly-created log, we store the
112 last several lines ("screenful", hence the choice of 24) of Wget
113 output, and dump them as context when the time comes. */
114 #define SAVED_LOG_LINES 24
116 /* log_lines is a circular buffer that stores SAVED_LOG_LINES lines of
117 output. log_line_current always points to the position in the
118 buffer that will be written to next. When log_line_current reaches
119 SAVED_LOG_LINES, it is reset to zero.
121 The problem here is that we'd have to either (re)allocate and free
122 strings all the time, or limit the lines to an arbitrary number of
123 characters. Instead of settling for either of these, we do both:
124 if the line is smaller than a certain "usual" line length (128
125 chars by default), a preallocated memory is used. The rare lines
126 that are longer than 128 characters are malloc'ed and freed
127 separately. This gives good performance with minimum memory
128 consumption and fragmentation. */
130 #define STATIC_LENGTH 128
132 static struct log_ln {
133 char static_line[STATIC_LENGTH + 1]; /* statically allocated
135 char *malloced_line; /* malloc'ed line, for lines of output
136 larger than 80 characters. */
137 char *content; /* this points either to malloced_line
138 or to the appropriate static_line.
139 If this is NULL, it means the line
140 has not yet been used. */
141 } log_lines[SAVED_LOG_LINES];
143 /* The current position in the ring. */
144 static int log_line_current = -1;
146 /* Whether the most recently written line was "trailing", i.e. did not
147 finish with \n. This is an important piece of information because
148 the code is always careful to append data to trailing lines, rather
149 than create new ones. */
150 static int trailing_line;
152 static void check_redirect_output PARAMS ((void));
154 #define ROT_ADVANCE(num) do { \
155 if (++num >= SAVED_LOG_LINES) \
159 /* Free the log line index with NUM. This calls free on
160 ln->malloced_line if it's non-NULL, and it also resets
161 ln->malloced_line and ln->content to NULL. */
164 free_log_line (int num)
166 struct log_ln *ln = log_lines + num;
167 if (ln->malloced_line)
169 xfree (ln->malloced_line);
170 ln->malloced_line = NULL;
175 /* Append bytes in the range [start, end) to one line in the log. The
176 region is not supposed to contain newlines, except for the last
177 character (at end[-1]). */
180 saved_append_1 (const char *start, const char *end)
182 int len = end - start;
186 /* First, check whether we need to append to an existing line or to
190 /* Create a new line. */
193 if (log_line_current == -1)
194 log_line_current = 0;
196 free_log_line (log_line_current);
197 ln = log_lines + log_line_current;
198 if (len > STATIC_LENGTH)
200 ln->malloced_line = strdupdelim (start, end);
201 ln->content = ln->malloced_line;
205 memcpy (ln->static_line, start, len);
206 ln->static_line[len] = '\0';
207 ln->content = ln->static_line;
212 /* Append to the last line. If the line is malloc'ed, we just
213 call realloc and append the new string. If the line is
214 static, we have to check whether appending the new string
215 would make it exceed STATIC_LENGTH characters, and if so,
216 convert it to malloc(). */
217 struct log_ln *ln = log_lines + log_line_current;
218 if (ln->malloced_line)
220 /* Resize malloc'ed line and append. */
221 int old_len = strlen (ln->malloced_line);
222 ln->malloced_line = xrealloc (ln->malloced_line, old_len + len + 1);
223 memcpy (ln->malloced_line + old_len, start, len);
224 ln->malloced_line[old_len + len] = '\0';
225 /* might have changed due to realloc */
226 ln->content = ln->malloced_line;
230 int old_len = strlen (ln->static_line);
231 if (old_len + len > STATIC_LENGTH)
233 /* Allocate memory and concatenate the old and the new
235 ln->malloced_line = xmalloc (old_len + len + 1);
236 memcpy (ln->malloced_line, ln->static_line,
238 memcpy (ln->malloced_line + old_len, start, len);
239 ln->malloced_line[old_len + len] = '\0';
240 ln->content = ln->malloced_line;
244 /* Just append to the old, statically allocated
246 memcpy (ln->static_line + old_len, start, len);
247 ln->static_line[old_len + len] = '\0';
248 ln->content = ln->static_line;
252 trailing_line = !(end[-1] == '\n');
254 ROT_ADVANCE (log_line_current);
257 /* Log the contents of S, as explained above. If S consists of
258 multiple lines, they are logged separately. If S does not end with
259 a newline, it will form a "trailing" line, to which things will get
260 appended the next time this function is called. */
263 saved_append (const char *s)
267 const char *end = strchr (s, '\n');
269 end = s + strlen (s);
272 saved_append_1 (s, end);
277 /* Check X against opt.verbose and opt.quiet. The semantics is as
280 * LOG_ALWAYS - print the message unconditionally;
282 * LOG_NOTQUIET - print the message if opt.quiet is non-zero;
284 * LOG_NONVERBOSE - print the message if opt.verbose is zero;
286 * LOG_VERBOSE - print the message if opt.verbose is non-zero. */
287 #define CHECK_VERBOSE(x) \
296 case LOG_NONVERBOSE: \
297 if (opt.verbose || opt.quiet) \
305 /* Returns the file descriptor for logging. This is LOGFP, except if
306 called before log_init, in which case it returns stderr. This is
307 useful in case someone calls a logging function before log_init.
309 If logging is inhibited, return NULL. */
321 /* Log a literal string S. The string is logged as-is, without a
325 logputs (enum log_options o, const char *s)
329 check_redirect_output ();
330 if (!(fp = get_log_fp ()))
343 struct logvprintf_state {
349 /* Print a message to the log. A copy of message will be saved to
350 saved_log, for later reusal by log_dump_context().
352 It is not possible to code this function in a "natural" way, using
353 a loop, because of the braindeadness of the varargs API.
354 Specifically, each call to vsnprintf() must be preceded by va_start
355 and followed by va_end. And this is possible only in the function
356 that contains the `...' declaration. The alternative would be to
357 use va_copy, but that's not portable. */
360 logvprintf (struct logvprintf_state *state, const char *fmt, va_list args)
363 char *write_ptr = smallmsg;
364 int available_size = sizeof (smallmsg);
366 FILE *fp = get_log_fp ();
370 /* In the simple case just call vfprintf(), to avoid needless
371 allocation and games with vsnprintf(). */
372 vfprintf (fp, fmt, args);
376 if (state->allocated != 0)
378 write_ptr = state->bigmsg;
379 available_size = state->allocated;
382 /* The GNU coding standards advise not to rely on the return value
383 of sprintf(). However, vsnprintf() is a relatively new function
384 missing from legacy systems. Therefore I consider it safe to
385 assume that its return value is meaningful. On the systems where
386 vsnprintf() is not available, we use the implementation from
387 snprintf.c which does return the correct value. */
388 numwritten = vsnprintf (write_ptr, available_size, fmt, args);
390 /* vsnprintf() will not step over the limit given by available_size.
391 If it fails, it will return either -1 (POSIX?) or the number of
392 characters that *would have* been written, if there had been
393 enough room (C99). In the former case, we double the
394 available_size and malloc to get a larger buffer, and try again.
395 In the latter case, we use the returned information to build a
396 buffer of the correct size. */
398 if (numwritten == -1)
400 /* Writing failed, and we don't know the needed size. Try
401 again with doubled size. */
402 int newsize = available_size << 1;
403 state->bigmsg = xrealloc (state->bigmsg, newsize);
404 state->allocated = newsize;
407 else if (numwritten >= available_size)
409 /* Writing failed, but we know exactly how much space we
411 int newsize = numwritten + 1;
412 state->bigmsg = xrealloc (state->bigmsg, newsize);
413 state->allocated = newsize;
417 /* Writing succeeded. */
418 saved_append (write_ptr);
419 fputs (write_ptr, fp);
421 xfree (state->bigmsg);
432 /* Flush LOGFP. Useful while flushing is disabled. */
436 FILE *fp = get_log_fp ();
442 /* Enable or disable log flushing. */
444 log_set_flush (int flush)
446 if (flush == flush_log_p)
451 /* Disable flushing by setting flush_log_p to 0. */
456 /* Reenable flushing. If anything was printed in no-flush mode,
457 flush the log now. */
464 /* (Temporarily) disable storing log to memory. Returns the old
465 status of storing, with which this function can be called again to
466 reestablish storing. */
469 log_set_save_context (int savep)
471 int old = save_context_p;
472 save_context_p = savep;
476 /* Handle difference in va_start between pre-ANSI and ANSI C. Note
477 that we always use `...' in function definitions and let ansi2knr
478 convert it for us. */
480 #ifdef WGET_USE_STDARG
481 # define VA_START(args, arg1) va_start (args, arg1)
483 # define VA_START(args, ignored) va_start (args)
486 /* Print a message to the screen or to the log. The first argument
487 defines the verbosity of the message, and the rest are as in
491 logprintf (enum log_options o, const char *fmt, ...)
494 struct logvprintf_state lpstate;
497 check_redirect_output ();
502 memset (&lpstate, '\0', sizeof (lpstate));
505 VA_START (args, fmt);
506 done = logvprintf (&lpstate, fmt, args);
513 /* The same as logprintf(), but does anything only if opt.debug is
516 debug_logprintf (const char *fmt, ...)
521 struct logvprintf_state lpstate;
524 check_redirect_output ();
528 memset (&lpstate, '\0', sizeof (lpstate));
531 VA_START (args, fmt);
532 done = logvprintf (&lpstate, fmt, args);
538 #endif /* ENABLE_DEBUG */
540 /* Open FILE and set up a logging stream. If FILE cannot be opened,
541 exit with status of 1. */
543 log_init (const char *file, int appendp)
547 logfp = fopen (file, appendp ? "a" : "w");
550 perror (opt.lfilename);
556 /* The log goes to stderr to avoid collisions with the output if
557 the user specifies `-O -'. #### Francois Pinard suggests
558 that it's a better idea to print to stdout by default, and to
559 stderr only if the user actually specifies `-O -'. He says
560 this inconsistency is harder to document, but is overall
561 easier on the user. */
564 /* If the output is a TTY, enable storing, which will make Wget
565 remember the last several printed messages, to be able to
566 dump them to a log file in case SIGHUP or SIGUSR1 is received
567 (or Ctrl+Break is pressed under Windows). */
570 && isatty (fileno (logfp))
579 /* Close LOGFP, inhibit further logging and free the memory associated
592 for (i = 0; i < SAVED_LOG_LINES; i++)
594 log_line_current = -1;
598 /* Dump saved lines to logfp. */
600 log_dump_context (void)
602 int num = log_line_current;
603 FILE *fp = get_log_fp ();
613 struct log_ln *ln = log_lines + num;
615 fputs (ln->content, fp);
618 while (num != log_line_current);
620 if (log_lines[log_line_current].content)
621 fputs (log_lines[log_line_current].content, fp);
625 /* When SIGHUP or SIGUSR1 are received, the output is redirected
626 elsewhere. Such redirection is only allowed once. */
627 enum { RR_NONE, RR_REQUESTED, RR_DONE } redirect_request = RR_NONE;
628 static const char *redirect_request_signal_name;
630 /* Redirect output to `wget-log'. */
633 redirect_output (void)
635 char *logfile = unique_name (DEFAULT_LOGFILE, 0);
636 fprintf (stderr, _("\n%s received, redirecting output to `%s'.\n"),
637 redirect_request_signal_name, logfile);
638 logfp = fopen (logfile, "w");
641 /* Eek! Opening the alternate log file has failed. Nothing we
642 can do but disable printing completely. */
643 fprintf (stderr, _("%s: %s; disabling logging.\n"),
644 logfile, strerror (errno));
649 /* Dump the context output to the newly opened log. */
656 /* Check whether a signal handler requested the output to be
660 check_redirect_output (void)
662 if (redirect_request == RR_REQUESTED)
664 redirect_request = RR_DONE;
669 /* Request redirection at a convenient time. This may be called from
673 log_request_redirect_output (const char *signal_name)
675 if (redirect_request == RR_NONE && save_context_p)
676 /* Request output redirection. The request will be processed by
677 check_redirect_output(), which is called from entry point log
679 redirect_request = RR_REQUESTED;
680 redirect_request_signal_name = signal_name;