2 Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006,
3 2007 Free Software Foundation, Inc.
5 This file is part of GNU Wget.
7 GNU Wget is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 GNU Wget is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with Wget. If not, see <http://www.gnu.org/licenses/>.
20 Additional permission under GNU GPL version 3 section 7
22 If you modify this program, or any covered work, by linking or
23 combining it with the OpenSSL project's OpenSSL library (or a
24 modified version of that library), containing parts covered by the
25 terms of the OpenSSL or SSLeay licenses, the Free Software Foundation
26 grants you additional permission to convey the resulting work.
27 Corresponding Source for a non-source form of such a combination
28 shall include the source code for the parts of OpenSSL used as well
29 as that of the covered work. */
47 /* This file impplement support for "logging". Logging means printing
48 output, plus several additional features:
50 - Cataloguing output by importance. You can specify that a log
51 message is "verbose" or "debug", and it will not be printed unless
52 in verbose or debug mode, respectively.
54 - Redirecting the log to the file. When Wget's output goes to the
55 terminal, and Wget receives SIGHUP, all further output is
56 redirected to a log file. When this is the case, Wget can also
57 print the last several lines of "context" to the log file so that
58 it does not begin in the middle of a line. For this to work, the
59 logging code stores the last several lines of context. Callers may
60 request for certain output not to be stored.
62 - Inhibiting output. When Wget receives SIGHUP, but redirecting
63 the output fails, logging is inhibited. */
66 /* The file descriptor used for logging. This is NULL before log_init
67 is called; logging functions log to stderr then. log_init sets it
68 either to stderr or to a file pointer obtained from fopen(). If
69 logging is inhibited, logfp is set back to NULL. */
72 /* If true, it means logging is inhibited, i.e. nothing is printed or
74 static bool inhibit_logging;
76 /* Whether the last output lines are stored for use as context. */
77 static bool save_context_p;
79 /* Whether the log is flushed after each command. */
80 static bool flush_log_p = true;
82 /* Whether any output has been received while flush_log_p was 0. */
83 static bool needs_flushing;
85 /* In the event of a hang-up, and if its output was on a TTY, Wget
86 redirects its output to `wget-log'.
88 For the convenience of reading this newly-created log, we store the
89 last several lines ("screenful", hence the choice of 24) of Wget
90 output, and dump them as context when the time comes. */
91 #define SAVED_LOG_LINES 24
93 /* log_lines is a circular buffer that stores SAVED_LOG_LINES lines of
94 output. log_line_current always points to the position in the
95 buffer that will be written to next. When log_line_current reaches
96 SAVED_LOG_LINES, it is reset to zero.
98 The problem here is that we'd have to either (re)allocate and free
99 strings all the time, or limit the lines to an arbitrary number of
100 characters. Instead of settling for either of these, we do both:
101 if the line is smaller than a certain "usual" line length (128
102 chars by default), a preallocated memory is used. The rare lines
103 that are longer than 128 characters are malloc'ed and freed
104 separately. This gives good performance with minimum memory
105 consumption and fragmentation. */
107 #define STATIC_LENGTH 128
109 static struct log_ln {
110 char static_line[STATIC_LENGTH + 1]; /* statically allocated
112 char *malloced_line; /* malloc'ed line, for lines of output
113 larger than 80 characters. */
114 char *content; /* this points either to malloced_line
115 or to the appropriate static_line.
116 If this is NULL, it means the line
117 has not yet been used. */
118 } log_lines[SAVED_LOG_LINES];
120 /* The current position in the ring. */
121 static int log_line_current = -1;
123 /* Whether the most recently written line was "trailing", i.e. did not
124 finish with \n. This is an important piece of information because
125 the code is always careful to append data to trailing lines, rather
126 than create new ones. */
127 static bool trailing_line;
129 static void check_redirect_output (void);
131 #define ROT_ADVANCE(num) do { \
132 if (++num >= SAVED_LOG_LINES) \
136 /* Free the log line index with NUM. This calls free on
137 ln->malloced_line if it's non-NULL, and it also resets
138 ln->malloced_line and ln->content to NULL. */
141 free_log_line (int num)
143 struct log_ln *ln = log_lines + num;
144 if (ln->malloced_line)
146 xfree (ln->malloced_line);
147 ln->malloced_line = NULL;
152 /* Append bytes in the range [start, end) to one line in the log. The
153 region is not supposed to contain newlines, except for the last
154 character (at end[-1]). */
157 saved_append_1 (const char *start, const char *end)
159 int len = end - start;
163 /* First, check whether we need to append to an existing line or to
167 /* Create a new line. */
170 if (log_line_current == -1)
171 log_line_current = 0;
173 free_log_line (log_line_current);
174 ln = log_lines + log_line_current;
175 if (len > STATIC_LENGTH)
177 ln->malloced_line = strdupdelim (start, end);
178 ln->content = ln->malloced_line;
182 memcpy (ln->static_line, start, len);
183 ln->static_line[len] = '\0';
184 ln->content = ln->static_line;
189 /* Append to the last line. If the line is malloc'ed, we just
190 call realloc and append the new string. If the line is
191 static, we have to check whether appending the new string
192 would make it exceed STATIC_LENGTH characters, and if so,
193 convert it to malloc(). */
194 struct log_ln *ln = log_lines + log_line_current;
195 if (ln->malloced_line)
197 /* Resize malloc'ed line and append. */
198 int old_len = strlen (ln->malloced_line);
199 ln->malloced_line = xrealloc (ln->malloced_line, old_len + len + 1);
200 memcpy (ln->malloced_line + old_len, start, len);
201 ln->malloced_line[old_len + len] = '\0';
202 /* might have changed due to realloc */
203 ln->content = ln->malloced_line;
207 int old_len = strlen (ln->static_line);
208 if (old_len + len > STATIC_LENGTH)
210 /* Allocate memory and concatenate the old and the new
212 ln->malloced_line = xmalloc (old_len + len + 1);
213 memcpy (ln->malloced_line, ln->static_line,
215 memcpy (ln->malloced_line + old_len, start, len);
216 ln->malloced_line[old_len + len] = '\0';
217 ln->content = ln->malloced_line;
221 /* Just append to the old, statically allocated
223 memcpy (ln->static_line + old_len, start, len);
224 ln->static_line[old_len + len] = '\0';
225 ln->content = ln->static_line;
229 trailing_line = !(end[-1] == '\n');
231 ROT_ADVANCE (log_line_current);
234 /* Log the contents of S, as explained above. If S consists of
235 multiple lines, they are logged separately. If S does not end with
236 a newline, it will form a "trailing" line, to which things will get
237 appended the next time this function is called. */
240 saved_append (const char *s)
244 const char *end = strchr (s, '\n');
246 end = s + strlen (s);
249 saved_append_1 (s, end);
254 /* Check X against opt.verbose and opt.quiet. The semantics is as
257 * LOG_ALWAYS - print the message unconditionally;
259 * LOG_NOTQUIET - print the message if opt.quiet is non-zero;
261 * LOG_NONVERBOSE - print the message if opt.verbose is zero;
263 * LOG_VERBOSE - print the message if opt.verbose is non-zero. */
264 #define CHECK_VERBOSE(x) \
273 case LOG_NONVERBOSE: \
274 if (opt.verbose || opt.quiet) \
282 /* Returns the file descriptor for logging. This is LOGFP, except if
283 called before log_init, in which case it returns stderr. This is
284 useful in case someone calls a logging function before log_init.
286 If logging is inhibited, return NULL. */
298 /* Log a literal string S. The string is logged as-is, without a
302 logputs (enum log_options o, const char *s)
306 check_redirect_output ();
307 if ((fp = get_log_fp ()) == NULL)
317 needs_flushing = true;
320 struct logvprintf_state {
326 /* Print a message to the log. A copy of message will be saved to
327 saved_log, for later reusal by log_dump_context().
329 Normally we'd want this function to loop around vsnprintf until
330 sufficient room is allocated, as the Linux man page recommends.
331 However each call to vsnprintf() must be preceded by va_start and
332 followed by va_end. Since calling va_start/va_end is possible only
333 in the function that contains the `...' declaration, we cannot call
334 vsnprintf more than once. Therefore this function saves its state
335 to logvprintf_state and signals the parent to call it again.
337 (An alternative approach would be to use va_copy, but that's not
341 log_vprintf_internal (struct logvprintf_state *state, const char *fmt,
345 char *write_ptr = smallmsg;
346 int available_size = sizeof (smallmsg);
348 FILE *fp = get_log_fp ();
352 /* In the simple case just call vfprintf(), to avoid needless
353 allocation and games with vsnprintf(). */
354 vfprintf (fp, fmt, args);
358 if (state->allocated != 0)
360 write_ptr = state->bigmsg;
361 available_size = state->allocated;
364 /* The GNU coding standards advise not to rely on the return value
365 of sprintf(). However, vsnprintf() is a relatively new function
366 missing from legacy systems. Therefore I consider it safe to
367 assume that its return value is meaningful. On the systems where
368 vsnprintf() is not available, we use the implementation from
369 snprintf.c which does return the correct value. */
370 numwritten = vsnprintf (write_ptr, available_size, fmt, args);
372 /* vsnprintf() will not step over the limit given by available_size.
373 If it fails, it returns either -1 (older implementations) or the
374 number of characters (not counting the terminating \0) that
375 *would have* been written if there had been enough room (C99).
376 In the former case, we double available_size and malloc to get a
377 larger buffer, and try again. In the latter case, we use the
378 returned information to build a buffer of the correct size. */
380 if (numwritten == -1)
382 /* Writing failed, and we don't know the needed size. Try
383 again with doubled size. */
384 int newsize = available_size << 1;
385 state->bigmsg = xrealloc (state->bigmsg, newsize);
386 state->allocated = newsize;
389 else if (numwritten >= available_size)
391 /* Writing failed, but we know exactly how much space we
393 int newsize = numwritten + 1;
394 state->bigmsg = xrealloc (state->bigmsg, newsize);
395 state->allocated = newsize;
399 /* Writing succeeded. */
400 saved_append (write_ptr);
401 fputs (write_ptr, fp);
403 xfree (state->bigmsg);
409 needs_flushing = true;
414 /* Flush LOGFP. Useful while flushing is disabled. */
418 FILE *fp = get_log_fp ();
421 needs_flushing = false;
424 /* Enable or disable log flushing. */
426 log_set_flush (bool flush)
428 if (flush == flush_log_p)
433 /* Disable flushing by setting flush_log_p to 0. */
438 /* Reenable flushing. If anything was printed in no-flush mode,
439 flush the log now. */
446 /* (Temporarily) disable storing log to memory. Returns the old
447 status of storing, with which this function can be called again to
448 reestablish storing. */
451 log_set_save_context (bool savep)
453 bool old = save_context_p;
454 save_context_p = savep;
458 /* Print a message to the screen or to the log. The first argument
459 defines the verbosity of the message, and the rest are as in
463 logprintf (enum log_options o, const char *fmt, ...)
466 struct logvprintf_state lpstate;
469 check_redirect_output ();
477 va_start (args, fmt);
478 done = log_vprintf_internal (&lpstate, fmt, args);
485 /* The same as logprintf(), but does anything only if opt.debug is
488 debug_logprintf (const char *fmt, ...)
493 struct logvprintf_state lpstate;
496 check_redirect_output ();
503 va_start (args, fmt);
504 done = log_vprintf_internal (&lpstate, fmt, args);
510 #endif /* ENABLE_DEBUG */
512 /* Open FILE and set up a logging stream. If FILE cannot be opened,
513 exit with status of 1. */
515 log_init (const char *file, bool appendp)
519 logfp = fopen (file, appendp ? "a" : "w");
522 fprintf (stderr, "%s: %s: %s\n", exec_name, file, strerror (errno));
528 /* The log goes to stderr to avoid collisions with the output if
529 the user specifies `-O -'. #### Francois Pinard suggests
530 that it's a better idea to print to stdout by default, and to
531 stderr only if the user actually specifies `-O -'. He says
532 this inconsistency is harder to document, but is overall
533 easier on the user. */
538 && isatty (fileno (logfp))
542 /* If the output is a TTY, enable save context, i.e. store
543 the most recent several messages ("context") and dump
544 them to a log file in case SIGHUP or SIGUSR1 is received
545 (or Ctrl+Break is pressed under Windows). */
546 save_context_p = true;
551 /* Close LOGFP, inhibit further logging and free the memory associated
561 inhibit_logging = true;
562 save_context_p = false;
564 for (i = 0; i < SAVED_LOG_LINES; i++)
566 log_line_current = -1;
567 trailing_line = false;
570 /* Dump saved lines to logfp. */
572 log_dump_context (void)
574 int num = log_line_current;
575 FILE *fp = get_log_fp ();
585 struct log_ln *ln = log_lines + num;
587 fputs (ln->content, fp);
590 while (num != log_line_current);
592 if (log_lines[log_line_current].content)
593 fputs (log_lines[log_line_current].content, fp);
597 /* String escape functions. */
599 /* Return the number of non-printable characters in SOURCE.
600 Non-printable characters are determined as per safe-ctype.c. */
603 count_nonprint (const char *source)
607 for (p = source, cnt = 0; *p; p++)
613 /* Copy SOURCE to DEST, escaping non-printable characters.
615 Non-printable refers to anything outside the non-control ASCII
616 range (32-126) which means that, for example, CR, LF, and TAB are
617 considered non-printable along with ESC, BS, and other control
618 chars. This is by design: it makes sure that messages from remote
619 servers cannot be easily used to deceive the users by mimicking
620 Wget's output. Disallowing non-ASCII characters is another
621 necessary security measure, which makes sure that remote servers
622 cannot garble the screen or guess the local charset and perform
625 Of course, the above mandates that escnonprint only be used in
626 contexts expected to be ASCII, such as when printing host names,
627 URL components, HTTP headers, FTP server messages, and the like.
629 ESCAPE is the leading character of the escape sequence. BASE
630 should be the base of the escape sequence, and must be either 8 for
633 DEST must point to a location with sufficient room to store an
634 encoded version of SOURCE. */
637 copy_and_escape (const char *source, char *dest, char escape, int base)
639 const char *from = source;
643 /* Copy chars from SOURCE to DEST, escaping non-printable ones. */
647 while ((c = *from++) != '\0')
653 *to++ = '0' + (c >> 6);
654 *to++ = '0' + ((c >> 3) & 7);
655 *to++ = '0' + (c & 7);
659 while ((c = *from++) != '\0')
665 *to++ = XNUM_TO_DIGIT (c >> 4);
666 *to++ = XNUM_TO_DIGIT (c & 0xf);
680 static struct ringel ring[RING_SIZE]; /* ring data */
683 escnonprint_internal (const char *str, char escape, int base)
685 static int ringpos; /* current ring position */
688 assert (base == 8 || base == 16);
690 nprcnt = count_nonprint (str);
692 /* If there are no non-printable chars in STR, don't bother
693 copying anything, just return STR. */
697 /* Set up a pointer to the current ring position, so we can write
698 simply r->X instead of ring[ringpos].X. */
699 struct ringel *r = ring + ringpos;
701 /* Every non-printable character is replaced with the escape char
702 and three (or two, depending on BASE) *additional* chars. Size
703 must also include the length of the original string and one
704 additional char for the terminating \0. */
705 int needed_size = strlen (str) + 1 + (base == 8 ? 3 * nprcnt : 2 * nprcnt);
707 /* If the current buffer is uninitialized or too small,
709 if (r->buffer == NULL || r->size < needed_size)
711 r->buffer = xrealloc (r->buffer, needed_size);
712 r->size = needed_size;
715 copy_and_escape (str, r->buffer, escape, base);
716 ringpos = (ringpos + 1) % RING_SIZE;
721 /* Return a pointer to a static copy of STR with the non-printable
722 characters escaped as \ooo. If there are no non-printable
723 characters in STR, STR is returned. See copy_and_escape for more
724 information on which characters are considered non-printable.
726 DON'T call this function on translated strings because escaping
727 will break them. Don't call it on literal strings from the source,
728 which are by definition trusted. If newlines are allowed in the
729 string, escape and print it line by line because escaping the whole
730 string will convert newlines to \012. (This is so that expectedly
731 single-line messages cannot use embedded newlines to mimic Wget's
732 output and deceive the user.)
734 escnonprint doesn't quote its escape character because it is notf
735 meant as a general and reversible quoting mechanism, but as a quick
736 way to defang binary junk sent by malicious or buggy servers.
738 NOTE: since this function can return a pointer to static data, be
739 careful to copy its result before calling it again. However, to be
740 more useful with printf, it maintains an internal ring of static
741 buffers to return. Currently the ring size is 3, which means you
742 can print up to three values in the same printf; if more is needed,
746 escnonprint (const char *str)
748 return escnonprint_internal (str, '\\', 8);
751 /* Return a pointer to a static copy of STR with the non-printable
752 characters escaped as %XX. If there are no non-printable
753 characters in STR, STR is returned.
755 See escnonprint for usage details. */
758 escnonprint_uri (const char *str)
760 return escnonprint_internal (str, '%', 16);
767 for (i = 0; i < countof (ring); i++)
768 xfree_null (ring[i].buffer);
771 /* When SIGHUP or SIGUSR1 are received, the output is redirected
772 elsewhere. Such redirection is only allowed once. */
773 static enum { RR_NONE, RR_REQUESTED, RR_DONE } redirect_request = RR_NONE;
774 static const char *redirect_request_signal_name;
776 /* Redirect output to `wget-log'. */
779 redirect_output (void)
782 logfp = unique_create (DEFAULT_LOGFILE, false, &logfile);
785 fprintf (stderr, _("\n%s received, redirecting output to `%s'.\n"),
786 redirect_request_signal_name, logfile);
788 /* Dump the context output to the newly opened log. */
793 /* Eek! Opening the alternate log file has failed. Nothing we
794 can do but disable printing completely. */
795 fprintf (stderr, _("\n%s received.\n"), redirect_request_signal_name);
796 fprintf (stderr, _("%s: %s; disabling logging.\n"),
797 logfile, strerror (errno));
798 inhibit_logging = true;
800 save_context_p = false;
803 /* Check whether a signal handler requested the output to be
807 check_redirect_output (void)
809 if (redirect_request == RR_REQUESTED)
811 redirect_request = RR_DONE;
816 /* Request redirection at a convenient time. This may be called from
820 log_request_redirect_output (const char *signal_name)
822 if (redirect_request == RR_NONE && save_context_p)
823 /* Request output redirection. The request will be processed by
824 check_redirect_output(), which is called from entry point log
826 redirect_request = RR_REQUESTED;
827 redirect_request_signal_name = signal_name;