1 /* Various utility functions.
2 Copyright (C) 2003 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. */
36 #else /* not HAVE_STRING_H */
38 #endif /* not HAVE_STRING_H */
39 #include <sys/types.h>
44 # include <sys/mman.h>
55 #ifdef HAVE_SYS_UTIME_H
56 # include <sys/utime.h>
60 # include <libc.h> /* for access() */
64 #ifdef WGET_USE_STDARG
70 /* For TIOCGWINSZ and friends: */
71 #ifdef HAVE_SYS_IOCTL_H
72 # include <sys/ioctl.h>
78 /* Needed for run_with_timeout. */
79 #undef USE_SIGNAL_TIMEOUT
87 #ifndef HAVE_SIGSETJMP
88 /* If sigsetjmp is a macro, configure won't pick it up. */
90 # define HAVE_SIGSETJMP
95 # ifdef HAVE_SIGSETJMP
96 # define USE_SIGNAL_TIMEOUT
99 # define USE_SIGNAL_TIMEOUT
111 /* Utility function: like xstrdup(), but also lowercases S. */
114 xstrdup_lower (const char *s)
116 char *copy = xstrdup (s);
123 /* Return a count of how many times CHR occurs in STRING. */
126 count_char (const char *string, char chr)
130 for (p = string; *p; p++)
136 /* Copy the string formed by two pointers (one on the beginning, other
137 on the char after the last char) to a new, malloc-ed location.
140 strdupdelim (const char *beg, const char *end)
142 char *res = (char *)xmalloc (end - beg + 1);
143 memcpy (res, beg, end - beg);
144 res[end - beg] = '\0';
148 /* Parse a string containing comma-separated elements, and return a
149 vector of char pointers with the elements. Spaces following the
150 commas are ignored. */
152 sepstring (const char *s)
166 res = (char **)xrealloc (res, (i + 2) * sizeof (char *));
167 res[i] = strdupdelim (p, s);
170 /* Skip the blanks following the ','. */
178 res = (char **)xrealloc (res, (i + 2) * sizeof (char *));
179 res[i] = strdupdelim (p, s);
184 #ifdef WGET_USE_STDARG
185 # define VA_START(args, arg1) va_start (args, arg1)
187 # define VA_START(args, ignored) va_start (args)
190 /* Like sprintf, but allocates a string of sufficient size with malloc
191 and returns it. GNU libc has a similar function named asprintf,
192 which requires the pointer to the string to be passed. */
195 aprintf (const char *fmt, ...)
197 /* This function is implemented using vsnprintf, which we provide
198 for the systems that don't have it. Therefore, it should be 100%
202 char *str = xmalloc (size);
209 /* See log_vprintf_internal for explanation why it's OK to rely
210 on the return value of vsnprintf. */
212 VA_START (args, fmt);
213 n = vsnprintf (str, size, fmt, args);
216 /* If the printing worked, return the string. */
217 if (n > -1 && n < size)
220 /* Else try again with a larger buffer. */
221 if (n > -1) /* C99 */
222 size = n + 1; /* precisely what is needed */
224 size <<= 1; /* twice the old size */
225 str = xrealloc (str, size);
227 return NULL; /* unreached */
230 /* Return pointer to a static char[] buffer in which zero-terminated
231 string-representation of TM (in form hh:mm:ss) is printed.
233 If TM is NULL, the current time will be used. */
236 time_str (time_t *tm)
238 static char output[15];
240 time_t secs = tm ? *tm : time (NULL);
244 /* In case of error, return the empty string. Maybe we should
245 just abort if this happens? */
249 ptm = localtime (&secs);
250 sprintf (output, "%02d:%02d:%02d", ptm->tm_hour, ptm->tm_min, ptm->tm_sec);
254 /* Like the above, but include the date: YYYY-MM-DD hh:mm:ss. */
257 datetime_str (time_t *tm)
259 static char output[20]; /* "YYYY-MM-DD hh:mm:ss" + \0 */
261 time_t secs = tm ? *tm : time (NULL);
265 /* In case of error, return the empty string. Maybe we should
266 just abort if this happens? */
270 ptm = localtime (&secs);
271 sprintf (output, "%04d-%02d-%02d %02d:%02d:%02d",
272 ptm->tm_year + 1900, ptm->tm_mon + 1, ptm->tm_mday,
273 ptm->tm_hour, ptm->tm_min, ptm->tm_sec);
277 /* The Windows versions of the following two functions are defined in
282 fork_to_background (void)
285 /* Whether we arrange our own version of opt.lfilename here. */
286 int logfile_changed = 0;
290 /* We must create the file immediately to avoid either a race
291 condition (which arises from using unique_name and failing to
292 use fopen_excl) or lying to the user about the log file name
293 (which arises from using unique_name, printing the name, and
294 using fopen_excl later on.) */
295 FILE *new_log_fp = unique_create (DEFAULT_LOGFILE, 0, &opt.lfilename);
311 /* parent, no error */
312 printf (_("Continuing in background, pid %d.\n"), (int)pid);
314 printf (_("Output will be written to `%s'.\n"), opt.lfilename);
315 exit (0); /* #### should we use _exit()? */
318 /* child: give up the privileges and keep running. */
320 freopen ("/dev/null", "r", stdin);
321 freopen ("/dev/null", "w", stdout);
322 freopen ("/dev/null", "w", stderr);
324 #endif /* not WINDOWS */
326 /* "Touch" FILE, i.e. make its atime and mtime equal to the time
327 specified with TM. */
329 touch (const char *file, time_t tm)
331 #ifdef HAVE_STRUCT_UTIMBUF
332 struct utimbuf times;
333 times.actime = times.modtime = tm;
336 times[0] = times[1] = tm;
339 if (utime (file, ×) == -1)
340 logprintf (LOG_NOTQUIET, "utime(%s): %s\n", file, strerror (errno));
343 /* Checks if FILE is a symbolic link, and removes it if it is. Does
344 nothing under MS-Windows. */
346 remove_link (const char *file)
351 if (lstat (file, &st) == 0 && S_ISLNK (st.st_mode))
353 DEBUGP (("Unlinking %s (symlink).\n", file));
356 logprintf (LOG_VERBOSE, _("Failed to unlink symlink `%s': %s\n"),
357 file, strerror (errno));
362 /* Does FILENAME exist? This is quite a lousy implementation, since
363 it supplies no error codes -- only a yes-or-no answer. Thus it
364 will return that a file does not exist if, e.g., the directory is
365 unreadable. I don't mind it too much currently, though. The
366 proper way should, of course, be to have a third, error state,
367 other than true/false, but that would introduce uncalled-for
368 additional complexity to the callers. */
370 file_exists_p (const char *filename)
373 return access (filename, F_OK) >= 0;
376 return stat (filename, &buf) >= 0;
380 /* Returns 0 if PATH is a directory, 1 otherwise (any kind of file).
381 Returns 0 on error. */
383 file_non_directory_p (const char *path)
386 /* Use lstat() rather than stat() so that symbolic links pointing to
387 directories can be identified correctly. */
388 if (lstat (path, &buf) != 0)
390 return S_ISDIR (buf.st_mode) ? 0 : 1;
393 /* Return the size of file named by FILENAME, or -1 if it cannot be
394 opened or seeked into. */
396 file_size (const char *filename)
398 #if defined(HAVE_FSEEKO) && defined(HAVE_FTELLO)
400 /* We use fseek rather than stat to determine the file size because
401 that way we can also verify that the file is readable without
402 explicitly checking for permissions. Inspired by the POST patch
404 FILE *fp = fopen (filename, "rb");
407 fseeko (fp, 0, SEEK_END);
413 if (stat (filename, &st) < 0)
419 /* stat file names named PREFIX.1, PREFIX.2, etc., until one that
420 doesn't exist is found. Return a freshly allocated copy of the
424 unique_name_1 (const char *prefix)
427 int plen = strlen (prefix);
428 char *template = (char *)alloca (plen + 1 + 24);
429 char *template_tail = template + plen;
431 memcpy (template, prefix, plen);
432 *template_tail++ = '.';
435 number_to_string (template_tail, count++);
436 while (file_exists_p (template));
438 return xstrdup (template);
441 /* Return a unique file name, based on FILE.
443 More precisely, if FILE doesn't exist, it is returned unmodified.
444 If not, FILE.1 is tried, then FILE.2, etc. The first FILE.<number>
445 file name that doesn't exist is returned.
447 The resulting file is not created, only verified that it didn't
448 exist at the point in time when the function was called.
449 Therefore, where security matters, don't rely that the file created
450 by this function exists until you open it with O_EXCL or
453 If ALLOW_PASSTHROUGH is 0, it always returns a freshly allocated
454 string. Otherwise, it may return FILE if the file doesn't exist
455 (and therefore doesn't need changing). */
458 unique_name (const char *file, int allow_passthrough)
460 /* If the FILE itself doesn't exist, return it without
462 if (!file_exists_p (file))
463 return allow_passthrough ? (char *)file : xstrdup (file);
465 /* Otherwise, find a numeric suffix that results in unused file name
467 return unique_name_1 (file);
470 /* Create a file based on NAME, except without overwriting an existing
471 file with that name. Providing O_EXCL is correctly implemented,
472 this function does not have the race condition associated with
473 opening the file returned by unique_name. */
476 unique_create (const char *name, int binary, char **opened_name)
478 /* unique file name, based on NAME */
479 char *uname = unique_name (name, 0);
481 while ((fp = fopen_excl (uname, binary)) == NULL && errno == EEXIST)
484 uname = unique_name (name, 0);
486 if (opened_name && fp != NULL)
489 *opened_name = uname;
501 /* Open the file for writing, with the addition that the file is
502 opened "exclusively". This means that, if the file already exists,
503 this function will *fail* and errno will be set to EEXIST. If
504 BINARY is set, the file will be opened in binary mode, equivalent
507 If opening the file fails for any reason, including the file having
508 previously existed, this function returns NULL and sets errno
512 fopen_excl (const char *fname, int binary)
516 int flags = O_WRONLY | O_CREAT | O_EXCL;
521 fd = open (fname, flags, 0666);
524 return fdopen (fd, binary ? "wb" : "w");
525 #else /* not O_EXCL */
526 return fopen (fname, binary ? "wb" : "w");
527 #endif /* not O_EXCL */
530 /* Create DIRECTORY. If some of the pathname components of DIRECTORY
531 are missing, create them first. In case any mkdir() call fails,
532 return its error status. Returns 0 on successful completion.
534 The behaviour of this function should be identical to the behaviour
535 of `mkdir -p' on systems where mkdir supports the `-p' option. */
537 make_directory (const char *directory)
539 int i, ret, quit = 0;
542 /* Make a copy of dir, to be able to write to it. Otherwise, the
543 function is unsafe if called with a read-only char *argument. */
544 STRDUP_ALLOCA (dir, directory);
546 /* If the first character of dir is '/', skip it (and thus enable
547 creation of absolute-pathname directories. */
548 for (i = (*dir == '/'); 1; ++i)
550 for (; dir[i] && dir[i] != '/'; i++)
555 /* Check whether the directory already exists. Allow creation of
556 of intermediate directories to fail, as the initial path components
557 are not necessarily directories! */
558 if (!file_exists_p (dir))
559 ret = mkdir (dir, 0777);
570 /* Merge BASE with FILE. BASE can be a directory or a file name, FILE
571 should be a file name.
573 file_merge("/foo/bar", "baz") => "/foo/baz"
574 file_merge("/foo/bar/", "baz") => "/foo/bar/baz"
575 file_merge("foo", "bar") => "bar"
577 In other words, it's a simpler and gentler version of uri_merge_1. */
580 file_merge (const char *base, const char *file)
583 const char *cut = (const char *)strrchr (base, '/');
586 return xstrdup (file);
588 result = (char *)xmalloc (cut - base + 1 + strlen (file) + 1);
589 memcpy (result, base, cut - base);
590 result[cut - base] = '/';
591 strcpy (result + (cut - base) + 1, file);
596 static int in_acclist PARAMS ((const char *const *, const char *, int));
598 /* Determine whether a file is acceptable to be followed, according to
599 lists of patterns to accept/reject. */
601 acceptable (const char *s)
605 while (l && s[l] != '/')
612 return (in_acclist ((const char *const *)opt.accepts, s, 1)
613 && !in_acclist ((const char *const *)opt.rejects, s, 1));
615 return in_acclist ((const char *const *)opt.accepts, s, 1);
617 else if (opt.rejects)
618 return !in_acclist ((const char *const *)opt.rejects, s, 1);
622 /* Compare S1 and S2 frontally; S2 must begin with S1. E.g. if S1 is
623 `/something', frontcmp() will return 1 only if S2 begins with
624 `/something'. Otherwise, 0 is returned. */
626 frontcmp (const char *s1, const char *s2)
628 for (; *s1 && *s2 && (*s1 == *s2); ++s1, ++s2);
632 /* Iterate through STRLIST, and return the first element that matches
633 S, through wildcards or front comparison (as appropriate). */
635 proclist (char **strlist, const char *s, enum accd flags)
639 for (x = strlist; *x; x++)
640 if (has_wildcards_p (*x))
642 if (fnmatch (*x, s, FNM_PATHNAME) == 0)
647 char *p = *x + ((flags & ALLABS) && (**x == '/')); /* Remove '/' */
654 /* Returns whether DIRECTORY is acceptable for download, wrt the
655 include/exclude lists.
657 If FLAGS is ALLABS, the leading `/' is ignored in paths; relative
658 and absolute paths may be freely intermixed. */
660 accdir (const char *directory, enum accd flags)
662 /* Remove starting '/'. */
663 if (flags & ALLABS && *directory == '/')
667 if (!proclist (opt.includes, directory, flags))
672 if (proclist (opt.excludes, directory, flags))
678 /* Return non-zero if STRING ends with TAIL. For instance:
680 match_tail ("abc", "bc", 0) -> 1
681 match_tail ("abc", "ab", 0) -> 0
682 match_tail ("abc", "abc", 0) -> 1
684 If FOLD_CASE_P is non-zero, the comparison will be
688 match_tail (const char *string, const char *tail, int fold_case_p)
692 /* We want this to be fast, so we code two loops, one with
693 case-folding, one without. */
697 for (i = strlen (string), j = strlen (tail); i >= 0 && j >= 0; i--, j--)
698 if (string[i] != tail[j])
703 for (i = strlen (string), j = strlen (tail); i >= 0 && j >= 0; i--, j--)
704 if (TOLOWER (string[i]) != TOLOWER (tail[j]))
708 /* If the tail was exhausted, the match was succesful. */
715 /* Checks whether string S matches each element of ACCEPTS. A list
716 element are matched either with fnmatch() or match_tail(),
717 according to whether the element contains wildcards or not.
719 If the BACKWARD is 0, don't do backward comparison -- just compare
722 in_acclist (const char *const *accepts, const char *s, int backward)
724 for (; *accepts; accepts++)
726 if (has_wildcards_p (*accepts))
728 /* fnmatch returns 0 if the pattern *does* match the
730 if (fnmatch (*accepts, s, 0) == 0)
737 if (match_tail (s, *accepts, 0))
742 if (!strcmp (s, *accepts))
750 /* Return the location of STR's suffix (file extension). Examples:
751 suffix ("foo.bar") -> "bar"
752 suffix ("foo.bar.baz") -> "baz"
753 suffix ("/foo/bar") -> NULL
754 suffix ("/foo.bar/baz") -> NULL */
756 suffix (const char *str)
760 for (i = strlen (str); i && str[i] != '/' && str[i] != '.'; i--)
764 return (char *)str + i;
769 /* Return non-zero if S contains globbing wildcards (`*', `?', `[' or
773 has_wildcards_p (const char *s)
776 if (*s == '*' || *s == '?' || *s == '[' || *s == ']')
781 /* Return non-zero if FNAME ends with a typical HTML suffix. The
782 following (case-insensitive) suffixes are presumed to be HTML files:
786 ?html (`?' matches one character)
788 #### CAVEAT. This is not necessarily a good indication that FNAME
789 refers to a file that contains HTML! */
791 has_html_suffix_p (const char *fname)
795 if ((suf = suffix (fname)) == NULL)
797 if (!strcasecmp (suf, "html"))
799 if (!strcasecmp (suf, "htm"))
801 if (suf[0] && !strcasecmp (suf + 1, "html"))
806 /* Read a line from FP and return the pointer to freshly allocated
807 storage. The storage space is obtained through malloc() and should
808 be freed with free() when it is no longer needed.
810 The length of the line is not limited, except by available memory.
811 The newline character at the end of line is retained. The line is
812 terminated with a zero character.
814 After end-of-file is encountered without anything being read, NULL
815 is returned. NULL is also returned on error. To distinguish
816 between these two cases, use the stdio function ferror(). */
819 read_whole_line (FILE *fp)
823 char *line = (char *)xmalloc (bufsize);
825 while (fgets (line + length, bufsize - length, fp))
827 length += strlen (line + length);
829 /* Possible for example when reading from a binary file where
830 a line begins with \0. */
833 if (line[length - 1] == '\n')
836 /* fgets() guarantees to read the whole line, or to use up the
837 space we've given it. We can double the buffer
840 line = xrealloc (line, bufsize);
842 if (length == 0 || ferror (fp))
847 if (length + 1 < bufsize)
848 /* Relieve the memory from our exponential greediness. We say
849 `length + 1' because the terminating \0 is not included in
850 LENGTH. We don't need to zero-terminate the string ourselves,
851 though, because fgets() does that. */
852 line = xrealloc (line, length + 1);
856 /* Read FILE into memory. A pointer to `struct file_memory' are
857 returned; use struct element `content' to access file contents, and
858 the element `length' to know the file length. `content' is *not*
859 zero-terminated, and you should *not* read or write beyond the [0,
860 length) range of characters.
862 After you are done with the file contents, call read_file_free to
865 Depending on the operating system and the type of file that is
866 being read, read_file() either mmap's the file into memory, or
867 reads the file into the core using read().
869 If file is named "-", fileno(stdin) is used for reading instead.
870 If you want to read from a real file named "-", use "./-" instead. */
873 read_file (const char *file)
876 struct file_memory *fm;
878 int inhibit_close = 0;
880 /* Some magic in the finest tradition of Perl and its kin: if FILE
881 is "-", just use stdin. */
886 /* Note that we don't inhibit mmap() in this case. If stdin is
887 redirected from a regular file, mmap() will still work. */
890 fd = open (file, O_RDONLY);
893 fm = xnew (struct file_memory);
898 if (fstat (fd, &buf) < 0)
900 fm->length = buf.st_size;
901 /* NOTE: As far as I know, the callers of this function never
902 modify the file text. Relying on this would enable us to
903 specify PROT_READ and MAP_SHARED for a marginal gain in
904 efficiency, but at some cost to generality. */
905 fm->content = mmap (NULL, fm->length, PROT_READ | PROT_WRITE,
907 if (fm->content == (char *)MAP_FAILED)
917 /* The most common reason why mmap() fails is that FD does not point
918 to a plain file. However, it's also possible that mmap() doesn't
919 work for a particular type of file. Therefore, whenever mmap()
920 fails, we just fall back to the regular method. */
921 #endif /* HAVE_MMAP */
924 size = 512; /* number of bytes fm->contents can
925 hold at any given time. */
926 fm->content = xmalloc (size);
930 if (fm->length > size / 2)
932 /* #### I'm not sure whether the whole exponential-growth
933 thing makes sense with kernel read. On Linux at least,
934 read() refuses to read more than 4K from a file at a
935 single chunk anyway. But other Unixes might optimize it
936 better, and it doesn't *hurt* anything, so I'm leaving
939 /* Normally, we grow SIZE exponentially to make the number
940 of calls to read() and realloc() logarithmic in relation
941 to file size. However, read() can read an amount of data
942 smaller than requested, and it would be unreasonable to
943 double SIZE every time *something* was read. Therefore,
944 we double SIZE only when the length exceeds half of the
945 entire allocated size. */
947 fm->content = xrealloc (fm->content, size);
949 nread = read (fd, fm->content + fm->length, size - fm->length);
951 /* Successful read. */
962 if (size > fm->length && fm->length != 0)
963 /* Due to exponential growth of fm->content, the allocated region
964 might be much larger than what is actually needed. */
965 fm->content = xrealloc (fm->content, fm->length);
977 /* Release the resources held by FM. Specifically, this calls
978 munmap() or xfree() on fm->content, depending whether mmap or
979 malloc/read were used to read in the file. It also frees the
980 memory needed to hold the FM structure itself. */
983 read_file_free (struct file_memory *fm)
988 munmap (fm->content, fm->length);
998 /* Free the pointers in a NULL-terminated vector of pointers, then
999 free the pointer itself. */
1001 free_vec (char **vec)
1012 /* Append vector V2 to vector V1. The function frees V2 and
1013 reallocates V1 (thus you may not use the contents of neither
1014 pointer after the call). If V1 is NULL, V2 is returned. */
1016 merge_vecs (char **v1, char **v2)
1026 /* To avoid j == 0 */
1031 for (i = 0; v1[i]; i++);
1033 for (j = 0; v2[j]; j++);
1034 /* Reallocate v1. */
1035 v1 = (char **)xrealloc (v1, (i + j + 1) * sizeof (char **));
1036 memcpy (v1 + i, v2, (j + 1) * sizeof (char *));
1041 /* A set of simple-minded routines to store strings in a linked list.
1042 This used to also be used for searching, but now we have hash
1045 /* It's a shame that these simple things like linked lists and hash
1046 tables (see hash.c) need to be implemented over and over again. It
1047 would be nice to be able to use the routines from glib -- see
1048 www.gtk.org for details. However, that would make Wget depend on
1049 glib, and I want to avoid dependencies to external libraries for
1050 reasons of convenience and portability (I suspect Wget is more
1051 portable than anything ever written for Gnome). */
1053 /* Append an element to the list. If the list has a huge number of
1054 elements, this can get slow because it has to find the list's
1055 ending. If you think you have to call slist_append in a loop,
1056 think about calling slist_prepend() followed by slist_nreverse(). */
1059 slist_append (slist *l, const char *s)
1061 slist *newel = xnew (slist);
1064 newel->string = xstrdup (s);
1069 /* Find the last element. */
1076 /* Prepend S to the list. Unlike slist_append(), this is O(1). */
1079 slist_prepend (slist *l, const char *s)
1081 slist *newel = xnew (slist);
1082 newel->string = xstrdup (s);
1087 /* Destructively reverse L. */
1090 slist_nreverse (slist *l)
1095 slist *next = l->next;
1103 /* Is there a specific entry in the list? */
1105 slist_contains (slist *l, const char *s)
1107 for (; l; l = l->next)
1108 if (!strcmp (l->string, s))
1113 /* Free the whole slist. */
1115 slist_free (slist *l)
1126 /* Sometimes it's useful to create "sets" of strings, i.e. special
1127 hash tables where you want to store strings as keys and merely
1128 query for their existence. Here is a set of utility routines that
1129 makes that transparent. */
1132 string_set_add (struct hash_table *ht, const char *s)
1134 /* First check whether the set element already exists. If it does,
1135 do nothing so that we don't have to free() the old element and
1136 then strdup() a new one. */
1137 if (hash_table_contains (ht, s))
1140 /* We use "1" as value. It provides us a useful and clear arbitrary
1141 value, and it consumes no memory -- the pointers to the same
1142 string "1" will be shared by all the key-value pairs in all `set'
1144 hash_table_put (ht, xstrdup (s), "1");
1147 /* Synonym for hash_table_contains... */
1150 string_set_contains (struct hash_table *ht, const char *s)
1152 return hash_table_contains (ht, s);
1156 string_set_free_mapper (void *key, void *value_ignored, void *arg_ignored)
1163 string_set_free (struct hash_table *ht)
1165 hash_table_map (ht, string_set_free_mapper, NULL);
1166 hash_table_destroy (ht);
1170 free_keys_and_values_mapper (void *key, void *value, void *arg_ignored)
1177 /* Another utility function: call free() on all keys and values of HT. */
1180 free_keys_and_values (struct hash_table *ht)
1182 hash_table_map (ht, free_keys_and_values_mapper, NULL);
1186 /* Engine for legible and legible_large_int; add thousand separators
1187 to numbers printed in strings. */
1190 legible_1 (const char *repr)
1192 static char outbuf[48];
1197 /* Reset the pointers. */
1201 /* Ignore the sign for the purpose of adding thousand
1208 /* How many digits before the first separator? */
1209 mod = strlen (inptr) % 3;
1211 for (i = 0; i < mod; i++)
1212 *outptr++ = inptr[i];
1213 /* Now insert the rest of them, putting separator before every
1215 for (i1 = i, i = 0; inptr[i1]; i++, i1++)
1217 if (i % 3 == 0 && i1 != 0)
1219 *outptr++ = inptr[i1];
1221 /* Zero-terminate the string. */
1226 /* Legible -- return a static pointer to the legibly printed wgint. */
1232 /* Print the number into the buffer. */
1233 number_to_string (inbuf, l);
1234 return legible_1 (inbuf);
1237 /* Write a string representation of LARGE_INT NUMBER into the provided
1238 buffer. The buffer should be able to accept 24 characters,
1239 including the terminating zero.
1241 It would be dangerous to use sprintf, because the code wouldn't
1242 work on a machine with gcc-provided long long support, but without
1243 libc support for "%lld". However, such platforms will typically
1244 not have snprintf and will use our version, which does support
1245 "%lld" where long longs are available. */
1248 large_int_to_string (char *buffer, LARGE_INT number)
1250 snprintf (buffer, 24, LARGE_INT_FMT, number);
1253 /* The same as legible(), but works on LARGE_INT. */
1256 legible_large_int (LARGE_INT l)
1259 large_int_to_string (inbuf, l);
1260 return legible_1 (inbuf);
1263 /* Count the digits in an integer number. */
1265 numdigit (wgint number)
1273 while ((number /= 10) > 0)
1278 #define ONE_DIGIT(figure) *p++ = n / (figure) + '0'
1279 #define ONE_DIGIT_ADVANCE(figure) (ONE_DIGIT (figure), n %= (figure))
1281 #define DIGITS_1(figure) ONE_DIGIT (figure)
1282 #define DIGITS_2(figure) ONE_DIGIT_ADVANCE (figure); DIGITS_1 ((figure) / 10)
1283 #define DIGITS_3(figure) ONE_DIGIT_ADVANCE (figure); DIGITS_2 ((figure) / 10)
1284 #define DIGITS_4(figure) ONE_DIGIT_ADVANCE (figure); DIGITS_3 ((figure) / 10)
1285 #define DIGITS_5(figure) ONE_DIGIT_ADVANCE (figure); DIGITS_4 ((figure) / 10)
1286 #define DIGITS_6(figure) ONE_DIGIT_ADVANCE (figure); DIGITS_5 ((figure) / 10)
1287 #define DIGITS_7(figure) ONE_DIGIT_ADVANCE (figure); DIGITS_6 ((figure) / 10)
1288 #define DIGITS_8(figure) ONE_DIGIT_ADVANCE (figure); DIGITS_7 ((figure) / 10)
1289 #define DIGITS_9(figure) ONE_DIGIT_ADVANCE (figure); DIGITS_8 ((figure) / 10)
1290 #define DIGITS_10(figure) ONE_DIGIT_ADVANCE (figure); DIGITS_9 ((figure) / 10)
1292 /* DIGITS_<11-20> are only used on machines with 64-bit numbers. */
1294 #define DIGITS_11(figure) ONE_DIGIT_ADVANCE (figure); DIGITS_10 ((figure) / 10)
1295 #define DIGITS_12(figure) ONE_DIGIT_ADVANCE (figure); DIGITS_11 ((figure) / 10)
1296 #define DIGITS_13(figure) ONE_DIGIT_ADVANCE (figure); DIGITS_12 ((figure) / 10)
1297 #define DIGITS_14(figure) ONE_DIGIT_ADVANCE (figure); DIGITS_13 ((figure) / 10)
1298 #define DIGITS_15(figure) ONE_DIGIT_ADVANCE (figure); DIGITS_14 ((figure) / 10)
1299 #define DIGITS_16(figure) ONE_DIGIT_ADVANCE (figure); DIGITS_15 ((figure) / 10)
1300 #define DIGITS_17(figure) ONE_DIGIT_ADVANCE (figure); DIGITS_16 ((figure) / 10)
1301 #define DIGITS_18(figure) ONE_DIGIT_ADVANCE (figure); DIGITS_17 ((figure) / 10)
1302 #define DIGITS_19(figure) ONE_DIGIT_ADVANCE (figure); DIGITS_18 ((figure) / 10)
1304 /* It is annoying that we have three different syntaxes for 64-bit constants:
1305 - nnnL for 64-bit systems, where they are of type long;
1306 - nnnLL for 32-bit systems that support long long;
1307 - nnnI64 for MS compiler on Windows, which doesn't support long long. */
1310 /* If long is large enough, use long constants. */
1311 # define C10000000000 10000000000L
1312 # define C100000000000 100000000000L
1313 # define C1000000000000 1000000000000L
1314 # define C10000000000000 10000000000000L
1315 # define C100000000000000 100000000000000L
1316 # define C1000000000000000 1000000000000000L
1317 # define C10000000000000000 10000000000000000L
1318 # define C100000000000000000 100000000000000000L
1319 # define C1000000000000000000 1000000000000000000L
1321 # if SIZEOF_LONG_LONG != 0
1322 /* Otherwise, if long long is available, use long long constants. */
1323 # define C10000000000 10000000000LL
1324 # define C100000000000 100000000000LL
1325 # define C1000000000000 1000000000000LL
1326 # define C10000000000000 10000000000000LL
1327 # define C100000000000000 100000000000000LL
1328 # define C1000000000000000 1000000000000000LL
1329 # define C10000000000000000 10000000000000000LL
1330 # define C100000000000000000 100000000000000000LL
1331 # define C1000000000000000000 1000000000000000000LL
1333 # if defined(WINDOWS)
1334 /* Use __int64 constants under Windows. */
1335 # define C10000000000 10000000000I64
1336 # define C100000000000 100000000000I64
1337 # define C1000000000000 1000000000000I64
1338 # define C10000000000000 10000000000000I64
1339 # define C100000000000000 100000000000000I64
1340 # define C1000000000000000 1000000000000000I64
1341 # define C10000000000000000 10000000000000000I64
1342 # define C100000000000000000 100000000000000000I64
1343 # define C1000000000000000000 1000000000000000000I64
1348 /* SPRINTF_WGINT is used by number_to_string to handle pathological
1349 cases and to portably support strange sizes of wgint. */
1350 #if SIZEOF_LONG >= SIZEOF_WGINT
1351 # define SPRINTF_WGINT(buf, n) sprintf(buf, "%ld", (long) (n))
1353 # if SIZEOF_LONG_LONG >= SIZEOF_WGINT
1354 # define SPRINTF_WGINT(buf, n) sprintf(buf, "%lld", (long long) (n))
1357 # define SPRINTF_WGINT(buf, n) sprintf(buf, "%I64", (__int64) (n))
1362 /* Print NUMBER to BUFFER in base 10. This is equivalent to
1363 `sprintf(buffer, "%lld", (long long) number)', only much faster and
1364 portable to machines without long long.
1366 The speedup may make a difference in programs that frequently
1367 convert numbers to strings. Some implementations of sprintf,
1368 particularly the one in GNU libc, have been known to be extremely
1369 slow when converting integers to strings.
1371 Return the pointer to the location where the terminating zero was
1372 printed. (Equivalent to calling buffer+strlen(buffer) after the
1375 BUFFER should be big enough to accept as many bytes as you expect
1376 the number to take up. On machines with 64-bit longs the maximum
1377 needed size is 24 bytes. That includes the digits needed for the
1378 largest 64-bit number, the `-' sign in case it's negative, and the
1379 terminating '\0'. */
1382 number_to_string (char *buffer, wgint number)
1387 #if (SIZEOF_WGINT != 4) && (SIZEOF_WGINT != 8)
1388 /* We are running in a strange or misconfigured environment. Let
1389 sprintf cope with it. */
1390 SPRINTF_WGINT (buffer, n);
1391 p += strlen (buffer);
1392 #else /* (SIZEOF_WGINT == 4) || (SIZEOF_WGINT == 8) */
1398 /* We cannot print a '-' and assign -n to n because -n would
1399 overflow. Let sprintf deal with this border case. */
1400 SPRINTF_WGINT (buffer, n);
1401 p += strlen (buffer);
1409 if (n < 10) { DIGITS_1 (1); }
1410 else if (n < 100) { DIGITS_2 (10); }
1411 else if (n < 1000) { DIGITS_3 (100); }
1412 else if (n < 10000) { DIGITS_4 (1000); }
1413 else if (n < 100000) { DIGITS_5 (10000); }
1414 else if (n < 1000000) { DIGITS_6 (100000); }
1415 else if (n < 10000000) { DIGITS_7 (1000000); }
1416 else if (n < 100000000) { DIGITS_8 (10000000); }
1417 else if (n < 1000000000) { DIGITS_9 (100000000); }
1418 #if SIZEOF_WGINT == 4
1419 /* wgint is four bytes long: we're done. */
1420 /* ``if (1)'' serves only to preserve editor indentation. */
1421 else if (1) { DIGITS_10 (1000000000); }
1423 /* wgint is 64 bits long -- make sure to process all the digits. */
1424 else if (n < C10000000000) { DIGITS_10 (1000000000); }
1425 else if (n < C100000000000) { DIGITS_11 (C10000000000); }
1426 else if (n < C1000000000000) { DIGITS_12 (C100000000000); }
1427 else if (n < C10000000000000) { DIGITS_13 (C1000000000000); }
1428 else if (n < C100000000000000) { DIGITS_14 (C10000000000000); }
1429 else if (n < C1000000000000000) { DIGITS_15 (C100000000000000); }
1430 else if (n < C10000000000000000) { DIGITS_16 (C1000000000000000); }
1431 else if (n < C100000000000000000) { DIGITS_17 (C10000000000000000); }
1432 else if (n < C1000000000000000000) { DIGITS_18 (C100000000000000000); }
1433 else { DIGITS_19 (C1000000000000000000); }
1437 #endif /* (SIZEOF_WGINT == 4) || (SIZEOF_WGINT == 8) */
1443 #undef ONE_DIGIT_ADVANCE
1467 /* Print NUMBER to a statically allocated string and return a pointer
1468 to the printed representation.
1470 This function is intended to be used in conjunction with printf.
1471 It is hard to portably print wgint values:
1472 a) you cannot use printf("%ld", number) because wgint can be long
1473 long on 32-bit machines with LFS.
1474 b) you cannot use printf("%lld", number) because NUMBER could be
1475 long on 32-bit machines without LFS, or on 64-bit machines,
1476 which do not require LFS. Also, Windows doesn't support %lld.
1477 c) you cannot use printf("%j", (int_max_t) number) because not all
1478 versions of printf support "%j", the most notable being the one
1480 d) you cannot #define WGINT_FMT to the appropriate format and use
1481 printf(WGINT_FMT, number) because that would break translations
1482 for user-visible messages, such as printf("Downloaded: %d
1485 What you should use instead is printf("%s", number_to_static_string
1488 CAVEAT: since the function returns pointers to static data, you
1489 must be careful to copy its result before calling it again.
1490 However, to make it more useful with printf, the function maintains
1491 an internal ring of static buffers to return. That way things like
1492 printf("%s %s", number_to_static_string (num1),
1493 number_to_static_string (num2)) work as expected. Three buffers
1494 are currently used, which means that "%s %s %s" will work, but "%s
1495 %s %s %s" won't. If you need to print more than three wgints,
1496 bump the RING_SIZE (or rethink your message.) */
1499 number_to_static_string (wgint number)
1501 static char ring[RING_SIZE][24];
1503 char *buf = ring[ringpos];
1504 number_to_string (buf, number);
1505 ringpos = (ringpos + 1) % RING_SIZE;
1509 /* Support for timers. */
1511 #undef TIMER_WINDOWS
1512 #undef TIMER_GETTIMEOFDAY
1515 /* Depending on the OS and availability of gettimeofday(), one and
1516 only one of the above constants will be defined. Virtually all
1517 modern Unix systems will define TIMER_GETTIMEOFDAY; Windows will
1518 use TIMER_WINDOWS. TIMER_TIME is a catch-all method for
1519 non-Windows systems without gettimeofday.
1521 #### Perhaps we should also support ftime(), which exists on old
1522 BSD 4.2-influenced systems? (It also existed under MS DOS Borland
1523 C, if memory serves me.) */
1526 # define TIMER_WINDOWS
1527 #else /* not WINDOWS */
1528 # ifdef HAVE_GETTIMEOFDAY
1529 # define TIMER_GETTIMEOFDAY
1533 #endif /* not WINDOWS */
1535 #ifdef TIMER_GETTIMEOFDAY
1536 typedef struct timeval wget_sys_time;
1540 typedef time_t wget_sys_time;
1543 #ifdef TIMER_WINDOWS
1544 typedef ULARGE_INTEGER wget_sys_time;
1548 /* Whether the start time has been initialized. */
1551 /* The starting point in time which, subtracted from the current
1552 time, yields elapsed time. */
1553 wget_sys_time start;
1555 /* The most recent elapsed time, calculated by wtimer_elapsed().
1556 Measured in milliseconds. */
1557 double elapsed_last;
1559 /* Approximately, the time elapsed between the true start of the
1560 measurement and the time represented by START. */
1561 double elapsed_pre_start;
1564 /* Allocate a timer. Calling wtimer_read on the timer will return
1565 zero. It is not legal to call wtimer_update with a freshly
1566 allocated timer -- use wtimer_reset first. */
1569 wtimer_allocate (void)
1571 struct wget_timer *wt = xnew (struct wget_timer);
1576 /* Allocate a new timer and reset it. Return the new timer. */
1581 struct wget_timer *wt = wtimer_allocate ();
1586 /* Free the resources associated with the timer. Its further use is
1590 wtimer_delete (struct wget_timer *wt)
1595 /* Store system time to WST. */
1598 wtimer_sys_set (wget_sys_time *wst)
1600 #ifdef TIMER_GETTIMEOFDAY
1601 gettimeofday (wst, NULL);
1608 #ifdef TIMER_WINDOWS
1609 /* We use GetSystemTime to get the elapsed time. MSDN warns that
1610 system clock adjustments can skew the output of GetSystemTime
1611 when used as a timer and gives preference to GetTickCount and
1612 high-resolution timers. But GetTickCount can overflow, and hires
1613 timers are typically used for profiling, not for regular time
1614 measurement. Since we handle clock skew anyway, we just use
1618 GetSystemTime (&st);
1620 /* As recommended by MSDN, we convert SYSTEMTIME to FILETIME, copy
1621 FILETIME to ULARGE_INTEGER, and use regular 64-bit integer
1622 arithmetic on that. */
1623 SystemTimeToFileTime (&st, &ft);
1624 wst->HighPart = ft.dwHighDateTime;
1625 wst->LowPart = ft.dwLowDateTime;
1629 /* Reset timer WT. This establishes the starting point from which
1630 wtimer_elapsed() will return the number of elapsed milliseconds.
1631 It is allowed to reset a previously used timer.
1633 If a non-zero value is used as START, the timer's values will be
1637 wtimer_reset (struct wget_timer *wt)
1639 /* Set the start time to the current time. */
1640 wtimer_sys_set (&wt->start);
1641 wt->elapsed_last = 0;
1642 wt->elapsed_pre_start = 0;
1643 wt->initialized = 1;
1647 wtimer_sys_diff (wget_sys_time *wst1, wget_sys_time *wst2)
1649 #ifdef TIMER_GETTIMEOFDAY
1650 return ((double)(wst1->tv_sec - wst2->tv_sec) * 1000
1651 + (double)(wst1->tv_usec - wst2->tv_usec) / 1000);
1655 return 1000 * (*wst1 - *wst2);
1659 /* VC++ 6 doesn't support direct cast of uint64 to double. To work
1660 around this, we subtract, then convert to signed, then finally to
1662 return (double)(signed __int64)(wst1->QuadPart - wst2->QuadPart) / 10000;
1666 /* Update the timer's elapsed interval. This function causes the
1667 timer to call gettimeofday (or time(), etc.) to update its idea of
1668 current time. To get the elapsed interval in milliseconds, use
1671 This function handles clock skew, i.e. time that moves backwards is
1675 wtimer_update (struct wget_timer *wt)
1680 assert (wt->initialized != 0);
1682 wtimer_sys_set (&now);
1683 elapsed = wt->elapsed_pre_start + wtimer_sys_diff (&now, &wt->start);
1685 /* Ideally we'd just return the difference between NOW and
1686 wt->start. However, the system timer can be set back, and we
1687 could return a value smaller than when we were last called, even
1688 a negative value. Both of these would confuse the callers, which
1689 expect us to return monotonically nondecreasing values.
1691 Therefore: if ELAPSED is smaller than its previous known value,
1692 we reset wt->start to the current time and effectively start
1693 measuring from this point. But since we don't want the elapsed
1694 value to start from zero, we set elapsed_pre_start to the last
1695 elapsed time and increment all future calculations by that
1698 if (elapsed < wt->elapsed_last)
1701 wt->elapsed_pre_start = wt->elapsed_last;
1702 elapsed = wt->elapsed_last;
1705 wt->elapsed_last = elapsed;
1708 /* Return the elapsed time in milliseconds between the last call to
1709 wtimer_reset and the last call to wtimer_update.
1711 A typical use of the timer interface would be:
1713 struct wtimer *timer = wtimer_new ();
1714 ... do something that takes a while ...
1716 double msecs = wtimer_read (); */
1719 wtimer_read (const struct wget_timer *wt)
1721 return wt->elapsed_last;
1724 /* Return the assessed granularity of the timer implementation, in
1725 milliseconds. This is used by code that tries to substitute a
1726 better value for timers that have returned zero. */
1729 wtimer_granularity (void)
1731 #ifdef TIMER_GETTIMEOFDAY
1732 /* Granularity of gettimeofday varies wildly between architectures.
1733 However, it appears that on modern machines it tends to be better
1734 than 1ms. Assume 100 usecs. (Perhaps the configure process
1735 could actually measure this?) */
1743 #ifdef TIMER_WINDOWS
1744 /* According to MSDN, GetSystemTime returns a broken-down time
1745 structure the smallest member of which are milliseconds. */
1750 /* This should probably be at a better place, but it doesn't really
1751 fit into html-parse.c. */
1753 /* The function returns the pointer to the malloc-ed quoted version of
1754 string s. It will recognize and quote numeric and special graphic
1755 entities, as per RFC1866:
1763 No other entities are recognized or replaced. */
1765 html_quote_string (const char *s)
1771 /* Pass through the string, and count the new size. */
1772 for (i = 0; *s; s++, i++)
1775 i += 4; /* `amp;' */
1776 else if (*s == '<' || *s == '>')
1777 i += 3; /* `lt;' and `gt;' */
1778 else if (*s == '\"')
1779 i += 5; /* `quot;' */
1783 res = (char *)xmalloc (i + 1);
1785 for (p = res; *s; s++)
1798 *p++ = (*s == '<' ? 'l' : 'g');
1825 /* Determine the width of the terminal we're running on. If that's
1826 not possible, return 0. */
1829 determine_screen_width (void)
1831 /* If there's a way to get the terminal size using POSIX
1832 tcgetattr(), somebody please tell me. */
1837 if (opt.lfilename != NULL)
1840 fd = fileno (stderr);
1841 if (ioctl (fd, TIOCGWINSZ, &wsz) < 0)
1842 return 0; /* most likely ENOTTY */
1845 #else /* not TIOCGWINSZ */
1847 CONSOLE_SCREEN_BUFFER_INFO csbi;
1848 if (!GetConsoleScreenBufferInfo (GetStdHandle (STD_ERROR_HANDLE), &csbi))
1850 return csbi.dwSize.X;
1851 # else /* neither WINDOWS nor TIOCGWINSZ */
1853 #endif /* neither WINDOWS nor TIOCGWINSZ */
1854 #endif /* not TIOCGWINSZ */
1857 /* Return a random number between 0 and MAX-1, inclusive.
1859 If MAX is greater than the value of RAND_MAX+1 on the system, the
1860 returned value will be in the range [0, RAND_MAX]. This may be
1861 fixed in a future release.
1863 The random number generator is seeded automatically the first time
1866 This uses rand() for portability. It has been suggested that
1867 random() offers better randomness, but this is not required for
1868 Wget, so I chose to go for simplicity and use rand
1871 DO NOT use this for cryptographic purposes. It is only meant to be
1872 used in situations where quality of the random numbers returned
1873 doesn't really matter. */
1876 random_number (int max)
1884 srand (time (NULL));
1889 /* On systems that don't define RAND_MAX, assume it to be 2**15 - 1,
1890 and enforce that assumption by masking other bits. */
1892 # define RAND_MAX 32767
1896 /* This is equivalent to rand() % max, but uses the high-order bits
1897 for better randomness on architecture where rand() is implemented
1898 using a simple congruential generator. */
1900 bounded = (double)max * rnd / (RAND_MAX + 1.0);
1901 return (int)bounded;
1904 /* Return a random uniformly distributed floating point number in the
1905 [0, 1) range. The precision of returned numbers is 9 digits.
1907 Modify this to use erand48() where available! */
1912 /* We can't rely on any specific value of RAND_MAX, but I'm pretty
1913 sure it's greater than 1000. */
1914 int rnd1 = random_number (1000);
1915 int rnd2 = random_number (1000);
1916 int rnd3 = random_number (1000);
1917 return rnd1 / 1000.0 + rnd2 / 1000000.0 + rnd3 / 1000000000.0;
1921 /* A debugging function for checking whether an MD5 library works. */
1923 #include "gen-md5.h"
1926 debug_test_md5 (char *buf)
1928 unsigned char raw[16];
1929 static char res[33];
1933 ALLOCA_MD5_CONTEXT (ctx);
1936 gen_md5_update ((unsigned char *)buf, strlen (buf), ctx);
1937 gen_md5_finish (ctx, raw);
1944 *p2++ = XNUM_TO_digit (*p1 >> 4);
1945 *p2++ = XNUM_TO_digit (*p1 & 0xf);
1954 /* Implementation of run_with_timeout, a generic timeout-forcing
1955 routine for systems with Unix-like signal handling. */
1957 #ifdef USE_SIGNAL_TIMEOUT
1958 # ifdef HAVE_SIGSETJMP
1959 # define SETJMP(env) sigsetjmp (env, 1)
1961 static sigjmp_buf run_with_timeout_env;
1964 abort_run_with_timeout (int sig)
1966 assert (sig == SIGALRM);
1967 siglongjmp (run_with_timeout_env, -1);
1969 # else /* not HAVE_SIGSETJMP */
1970 # define SETJMP(env) setjmp (env)
1972 static jmp_buf run_with_timeout_env;
1975 abort_run_with_timeout (int sig)
1977 assert (sig == SIGALRM);
1978 /* We don't have siglongjmp to preserve the set of blocked signals;
1979 if we longjumped out of the handler at this point, SIGALRM would
1980 remain blocked. We must unblock it manually. */
1981 int mask = siggetmask ();
1982 mask &= ~sigmask (SIGALRM);
1985 /* Now it's safe to longjump. */
1986 longjmp (run_with_timeout_env, -1);
1988 # endif /* not HAVE_SIGSETJMP */
1990 /* Arrange for SIGALRM to be delivered in TIMEOUT seconds. This uses
1991 setitimer where available, alarm otherwise.
1993 TIMEOUT should be non-zero. If the timeout value is so small that
1994 it would be rounded to zero, it is rounded to the least legal value
1995 instead (1us for setitimer, 1s for alarm). That ensures that
1996 SIGALRM will be delivered in all cases. */
1999 alarm_set (double timeout)
2002 /* Use the modern itimer interface. */
2003 struct itimerval itv;
2005 itv.it_value.tv_sec = (long) timeout;
2006 itv.it_value.tv_usec = 1000000L * (timeout - (long)timeout);
2007 if (itv.it_value.tv_sec == 0 && itv.it_value.tv_usec == 0)
2008 /* Ensure that we wait for at least the minimum interval.
2009 Specifying zero would mean "wait forever". */
2010 itv.it_value.tv_usec = 1;
2011 setitimer (ITIMER_REAL, &itv, NULL);
2012 #else /* not ITIMER_REAL */
2013 /* Use the old alarm() interface. */
2014 int secs = (int) timeout;
2016 /* Round TIMEOUTs smaller than 1 to 1, not to zero. This is
2017 because alarm(0) means "never deliver the alarm", i.e. "wait
2018 forever", which is not what someone who specifies a 0.5s
2019 timeout would expect. */
2022 #endif /* not ITIMER_REAL */
2025 /* Cancel the alarm set with alarm_set. */
2031 struct itimerval disable;
2033 setitimer (ITIMER_REAL, &disable, NULL);
2034 #else /* not ITIMER_REAL */
2036 #endif /* not ITIMER_REAL */
2039 /* Call FUN(ARG), but don't allow it to run for more than TIMEOUT
2040 seconds. Returns non-zero if the function was interrupted with a
2041 timeout, zero otherwise.
2043 This works by setting up SIGALRM to be delivered in TIMEOUT seconds
2044 using setitimer() or alarm(). The timeout is enforced by
2045 longjumping out of the SIGALRM handler. This has several
2046 advantages compared to the traditional approach of relying on
2047 signals causing system calls to exit with EINTR:
2049 * The callback function is *forcibly* interrupted after the
2050 timeout expires, (almost) regardless of what it was doing and
2051 whether it was in a syscall. For example, a calculation that
2052 takes a long time is interrupted as reliably as an IO
2055 * It works with both SYSV and BSD signals because it doesn't
2056 depend on the default setting of SA_RESTART.
2058 * It doesn't special handler setup beyond a simple call to
2059 signal(). (It does use sigsetjmp/siglongjmp, but they're
2062 The only downside is that, if FUN allocates internal resources that
2063 are normally freed prior to exit from the functions, they will be
2064 lost in case of timeout. */
2067 run_with_timeout (double timeout, void (*fun) (void *), void *arg)
2077 signal (SIGALRM, abort_run_with_timeout);
2078 if (SETJMP (run_with_timeout_env) != 0)
2080 /* Longjumped out of FUN with a timeout. */
2081 signal (SIGALRM, SIG_DFL);
2084 alarm_set (timeout);
2087 /* Preserve errno in case alarm() or signal() modifies it. */
2088 saved_errno = errno;
2090 signal (SIGALRM, SIG_DFL);
2091 errno = saved_errno;
2096 #else /* not USE_SIGNAL_TIMEOUT */
2099 /* A stub version of run_with_timeout that just calls FUN(ARG). Don't
2100 define it under Windows, because Windows has its own version of
2101 run_with_timeout that uses threads. */
2104 run_with_timeout (double timeout, void (*fun) (void *), void *arg)
2109 #endif /* not WINDOWS */
2110 #endif /* not USE_SIGNAL_TIMEOUT */
2114 /* Sleep the specified amount of seconds. On machines without
2115 nanosleep(), this may sleep shorter if interrupted by signals. */
2118 xsleep (double seconds)
2120 #ifdef HAVE_NANOSLEEP
2121 /* nanosleep is the preferred interface because it offers high
2122 accuracy and, more importantly, because it allows us to reliably
2123 restart after having been interrupted by a signal such as
2125 struct timespec sleep, remaining;
2126 sleep.tv_sec = (long) seconds;
2127 sleep.tv_nsec = 1000000000L * (seconds - (long) seconds);
2128 while (nanosleep (&sleep, &remaining) < 0 && errno == EINTR)
2129 /* If nanosleep has been interrupted by a signal, adjust the
2130 sleeping period and return to sleep. */
2132 #else /* not HAVE_NANOSLEEP */
2134 /* If usleep is available, use it in preference to select. */
2137 /* On some systems, usleep cannot handle values larger than
2138 1,000,000. If the period is larger than that, use sleep
2139 first, then add usleep for subsecond accuracy. */
2141 seconds -= (long) seconds;
2143 usleep (seconds * 1000000L);
2144 #else /* not HAVE_USLEEP */
2146 struct timeval sleep;
2147 sleep.tv_sec = (long) seconds;
2148 sleep.tv_usec = 1000000L * (seconds - (long) seconds);
2149 select (0, NULL, NULL, NULL, &sleep);
2150 /* If select returns -1 and errno is EINTR, it means we were
2151 interrupted by a signal. But without knowing how long we've
2152 actually slept, we can't return to sleep. Using gettimeofday to
2153 track sleeps is slow and unreliable due to clock skew. */
2154 #else /* not HAVE_SELECT */
2156 #endif /* not HAVE_SELECT */
2157 #endif /* not HAVE_USLEEP */
2158 #endif /* not HAVE_NANOSLEEP */
2161 #endif /* not WINDOWS */