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. */
30 # define WGET_USE_STDARG
48 /* This file impplement support for "logging". Logging means printing
49 output, plus several additional features:
51 - Cataloguing output by importance. You can specify that a log
52 message is "verbose" or "debug", and it will not be printed unless
53 in verbose or debug mode, respectively.
55 - Redirecting the log to the file. When Wget's output goes to the
56 terminal, and Wget receives SIGHUP, all further output is
57 redirected to a log file. When this is the case, Wget can also
58 print the last several lines of "context" to the log file so that
59 it does not begin in the middle of a line. For this to work, the
60 logging code stores the last several lines of context. Callers may
61 request for certain output not to be stored.
63 - Inhibiting output. When Wget receives SIGHUP, but redirecting
64 the output fails, logging is inhibited. */
67 /* The file descriptor used for logging. This is NULL before log_init
68 is called; logging functions log to stderr then. log_init sets it
69 either to stderr or to a file pointer obtained from fopen(). If
70 logging is inhibited, logfp is set back to NULL. */
73 /* If non-zero, it means logging is inhibited, i.e. nothing is printed
75 static int inhibit_logging;
77 /* Whether the last output lines are stored for use as context. */
78 static int save_context_p;
80 /* Whether the log is flushed after each command. */
81 static int flush_log_p = 1;
83 /* Whether any output has been received while flush_log_p was 0. */
84 static int needs_flushing;
86 /* In the event of a hang-up, and if its output was on a TTY, Wget
87 redirects its output to `wget-log'.
89 For the convenience of reading this newly-created log, we store the
90 last several lines ("screenful", hence the choice of 24) of Wget
91 output, and dump them as context when the time comes. */
92 #define SAVED_LOG_LINES 24
94 /* log_lines is a circular buffer that stores SAVED_LOG_LINES lines of
95 output. log_line_current always points to the position in the
96 buffer that will be written to next. When log_line_current reaches
97 SAVED_LOG_LINES, it is reset to zero.
99 The problem here is that we'd have to either (re)allocate and free
100 strings all the time, or limit the lines to an arbitrary number of
101 characters. Instead of settling for either of these, we do both:
102 if the line is smaller than a certain "usual" line length (128
103 chars by default), a preallocated memory is used. The rare lines
104 that are longer than 128 characters are malloc'ed and freed
105 separately. This gives good performance with minimum memory
106 consumption and fragmentation. */
108 #define STATIC_LENGTH 128
110 static struct log_ln {
111 char static_line[STATIC_LENGTH + 1]; /* statically allocated
113 char *malloced_line; /* malloc'ed line, for lines of output
114 larger than 80 characters. */
115 char *content; /* this points either to malloced_line
116 or to the appropriate static_line.
117 If this is NULL, it means the line
118 has not yet been used. */
119 } log_lines[SAVED_LOG_LINES];
121 /* The current position in the ring. */
122 static int log_line_current = -1;
124 /* Whether the most recently written line was "trailing", i.e. did not
125 finish with \n. This is an important piece of information because
126 the code is always careful to append data to trailing lines, rather
127 than create new ones. */
128 static int trailing_line;
130 static void check_redirect_output PARAMS ((void));
132 #define ROT_ADVANCE(num) do { \
133 if (++num >= SAVED_LOG_LINES) \
137 /* Free the log line index with NUM. This calls free on
138 ln->malloced_line if it's non-NULL, and it also resets
139 ln->malloced_line and ln->content to NULL. */
142 free_log_line (int num)
144 struct log_ln *ln = log_lines + num;
145 if (ln->malloced_line)
147 xfree (ln->malloced_line);
148 ln->malloced_line = NULL;
153 /* Append bytes in the range [start, end) to one line in the log. The
154 region is not supposed to contain newlines, except for the last
155 character (at end[-1]). */
158 saved_append_1 (const char *start, const char *end)
160 int len = end - start;
164 /* First, check whether we need to append to an existing line or to
168 /* Create a new line. */
171 if (log_line_current == -1)
172 log_line_current = 0;
174 free_log_line (log_line_current);
175 ln = log_lines + log_line_current;
176 if (len > STATIC_LENGTH)
178 ln->malloced_line = strdupdelim (start, end);
179 ln->content = ln->malloced_line;
183 memcpy (ln->static_line, start, len);
184 ln->static_line[len] = '\0';
185 ln->content = ln->static_line;
190 /* Append to the last line. If the line is malloc'ed, we just
191 call realloc and append the new string. If the line is
192 static, we have to check whether appending the new string
193 would make it exceed STATIC_LENGTH characters, and if so,
194 convert it to malloc(). */
195 struct log_ln *ln = log_lines + log_line_current;
196 if (ln->malloced_line)
198 /* Resize malloc'ed line and append. */
199 int old_len = strlen (ln->malloced_line);
200 ln->malloced_line = xrealloc (ln->malloced_line, old_len + len + 1);
201 memcpy (ln->malloced_line + old_len, start, len);
202 ln->malloced_line[old_len + len] = '\0';
203 /* might have changed due to realloc */
204 ln->content = ln->malloced_line;
208 int old_len = strlen (ln->static_line);
209 if (old_len + len > STATIC_LENGTH)
211 /* Allocate memory and concatenate the old and the new
213 ln->malloced_line = xmalloc (old_len + len + 1);
214 memcpy (ln->malloced_line, ln->static_line,
216 memcpy (ln->malloced_line + old_len, start, len);
217 ln->malloced_line[old_len + len] = '\0';
218 ln->content = ln->malloced_line;
222 /* Just append to the old, statically allocated
224 memcpy (ln->static_line + old_len, start, len);
225 ln->static_line[old_len + len] = '\0';
226 ln->content = ln->static_line;
230 trailing_line = !(end[-1] == '\n');
232 ROT_ADVANCE (log_line_current);
235 /* Log the contents of S, as explained above. If S consists of
236 multiple lines, they are logged separately. If S does not end with
237 a newline, it will form a "trailing" line, to which things will get
238 appended the next time this function is called. */
241 saved_append (const char *s)
245 const char *end = strchr (s, '\n');
247 end = s + strlen (s);
250 saved_append_1 (s, end);
255 /* Check X against opt.verbose and opt.quiet. The semantics is as
258 * LOG_ALWAYS - print the message unconditionally;
260 * LOG_NOTQUIET - print the message if opt.quiet is non-zero;
262 * LOG_NONVERBOSE - print the message if opt.verbose is zero;
264 * LOG_VERBOSE - print the message if opt.verbose is non-zero. */
265 #define CHECK_VERBOSE(x) \
274 case LOG_NONVERBOSE: \
275 if (opt.verbose || opt.quiet) \
283 /* Returns the file descriptor for logging. This is LOGFP, except if
284 called before log_init, in which case it returns stderr. This is
285 useful in case someone calls a logging function before log_init.
287 If logging is inhibited, return NULL. */
299 /* Log a literal string S. The string is logged as-is, without a
303 logputs (enum log_options o, const char *s)
307 check_redirect_output ();
308 if (!(fp = get_log_fp ()))
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 It is not possible to code this function in a "natural" way, using
330 a loop, because of the braindeadness of the varargs API.
331 Specifically, each call to vsnprintf() must be preceded by va_start
332 and followed by va_end. And this is possible only in the function
333 that contains the `...' declaration. The alternative would be to
334 use va_copy, but that's not portable. */
337 logvprintf (struct logvprintf_state *state, const char *fmt, va_list args)
340 char *write_ptr = smallmsg;
341 int available_size = sizeof (smallmsg);
343 FILE *fp = get_log_fp ();
347 /* In the simple case just call vfprintf(), to avoid needless
348 allocation and games with vsnprintf(). */
349 vfprintf (fp, fmt, args);
353 if (state->allocated != 0)
355 write_ptr = state->bigmsg;
356 available_size = state->allocated;
359 /* The GNU coding standards advise not to rely on the return value
360 of sprintf(). However, vsnprintf() is a relatively new function
361 missing from legacy systems. Therefore I consider it safe to
362 assume that its return value is meaningful. On the systems where
363 vsnprintf() is not available, we use the implementation from
364 snprintf.c which does return the correct value. */
365 numwritten = vsnprintf (write_ptr, available_size, fmt, args);
367 /* vsnprintf() will not step over the limit given by available_size.
368 If it fails, it will return either -1 (POSIX?) or the number of
369 characters that *would have* been written, if there had been
370 enough room. In the former case, we double the available_size
371 and malloc() to get a larger buffer, and try again. In the
372 latter case, we use the returned information to build a buffer of
375 if (numwritten == -1)
377 /* Writing failed, and we don't know the needed size. Try
378 again with doubled size. */
379 int newsize = available_size << 1;
380 state->bigmsg = xrealloc (state->bigmsg, newsize);
381 state->allocated = newsize;
384 else if (numwritten >= available_size)
386 /* Writing failed, but we know exactly how much space we
388 int newsize = numwritten + 1;
389 state->bigmsg = xrealloc (state->bigmsg, newsize);
390 state->allocated = newsize;
394 /* Writing succeeded. */
395 saved_append (write_ptr);
396 fputs (write_ptr, fp);
398 xfree (state->bigmsg);
409 /* Flush LOGFP. Useful while flushing is disabled. */
413 FILE *fp = get_log_fp ();
419 /* Enable or disable log flushing. */
421 log_set_flush (int flush)
423 if (flush == flush_log_p)
428 /* Disable flushing by setting flush_log_p to 0. */
433 /* Reenable flushing. If anything was printed in no-flush mode,
434 flush the log now. */
441 /* (Temporarily) disable storing log to memory. Returns the old
442 status of storing, with which this function can be called again to
443 reestablish storing. */
446 log_set_save_context (int savep)
448 int old = save_context_p;
449 save_context_p = savep;
453 #ifdef WGET_USE_STDARG
454 # define VA_START_1(arg1_type, arg1, args) va_start(args, arg1)
455 # define VA_START_2(arg1_type, arg1, arg2_type, arg2, args) va_start(args, arg2)
456 #else /* not WGET_USE_STDARG */
457 # define VA_START_1(arg1_type, arg1, args) do { \
459 arg1 = va_arg (args, arg1_type); \
461 # define VA_START_2(arg1_type, arg1, arg2_type, arg2, args) do { \
463 arg1 = va_arg (args, arg1_type); \
464 arg2 = va_arg (args, arg2_type); \
466 #endif /* not WGET_USE_STDARG */
468 /* Portability with pre-ANSI compilers makes these two functions look
471 #ifdef WGET_USE_STDARG
473 logprintf (enum log_options o, const char *fmt, ...)
474 #else /* not WGET_USE_STDARG */
478 #endif /* not WGET_USE_STDARG */
481 struct logvprintf_state lpstate;
484 #ifndef WGET_USE_STDARG
488 /* Perform a "dry run" of VA_START_2 to get the value of O. */
489 VA_START_2 (enum log_options, o, char *, fmt, args);
493 check_redirect_output ();
498 memset (&lpstate, '\0', sizeof (lpstate));
501 VA_START_2 (enum log_options, o, char *, fmt, args);
502 done = logvprintf (&lpstate, fmt, args);
509 /* The same as logprintf(), but does anything only if opt.debug is
511 #ifdef WGET_USE_STDARG
513 debug_logprintf (const char *fmt, ...)
514 #else /* not WGET_USE_STDARG */
516 debug_logprintf (va_alist)
518 #endif /* not WGET_USE_STDARG */
523 #ifndef WGET_USE_STDARG
526 struct logvprintf_state lpstate;
529 check_redirect_output ();
533 memset (&lpstate, '\0', sizeof (lpstate));
536 VA_START_1 (char *, fmt, args);
537 done = logvprintf (&lpstate, fmt, args);
545 /* Open FILE and set up a logging stream. If FILE cannot be opened,
546 exit with status of 1. */
548 log_init (const char *file, int appendp)
552 logfp = fopen (file, appendp ? "a" : "w");
555 perror (opt.lfilename);
561 /* The log goes to stderr to avoid collisions with the output if
562 the user specifies `-O -'. #### Francois Pinard suggests
563 that it's a better idea to print to stdout by default, and to
564 stderr only if the user actually specifies `-O -'. He says
565 this inconsistency is harder to document, but is overall
566 easier on the user. */
569 /* If the output is a TTY, enable storing, which will make Wget
570 remember all the printed messages, to be able to dump them to
571 a log file in case SIGHUP or SIGUSR1 is received (or
572 Ctrl+Break is pressed under Windows). */
575 && isatty (fileno (logfp))
584 /* Close LOGFP, inhibit further logging and free the memory associated
597 for (i = 0; i < SAVED_LOG_LINES; i++)
599 log_line_current = -1;
603 /* Dump saved lines to logfp. */
605 log_dump_context (void)
607 int num = log_line_current;
608 FILE *fp = get_log_fp ();
618 struct log_ln *ln = log_lines + num;
620 fputs (ln->content, fp);
623 while (num != log_line_current);
625 if (log_lines[log_line_current].content)
626 fputs (log_lines[log_line_current].content, fp);
630 /* When SIGHUP or SIGUSR1 are received, the output is redirected
631 elsewhere. Such redirection is only allowed once. */
632 enum { RR_NONE, RR_REQUESTED, RR_DONE } redirect_request = RR_NONE;
633 static const char *redirect_request_signal_name;
635 /* Redirect output to `wget-log'. */
638 redirect_output (void)
640 char *logfile = unique_name (DEFAULT_LOGFILE);
641 fprintf (stderr, _("\n%s received, redirecting output to `%s'.\n"),
642 redirect_request_signal_name, logfile);
643 logfp = fopen (logfile, "w");
646 /* Eek! Opening the alternate log file has failed. Nothing we
647 can do but disable printing completely. */
648 fprintf (stderr, _("%s: %s; disabling logging.\n"),
649 logfile, strerror (errno));
654 /* Dump the context output to the newly opened log. */
661 /* Check whether a signal handler requested the output to be
665 check_redirect_output (void)
667 if (redirect_request == RR_REQUESTED)
669 redirect_request = RR_DONE;
674 /* Request redirection at a convenient time. This may be called from
678 log_request_redirect_output (const char *signal_name)
680 if (redirect_request == RR_NONE && save_context_p)
681 /* Request output redirection. The request will be processed by
682 check_redirect_output(), which is called from entry point log
684 redirect_request = RR_REQUESTED;
685 redirect_request_signal_name = signal_name;