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)
544 /* Make a copy of dir, to be able to write to it. Otherwise, the
545 function is unsafe if called with a read-only char *argument. */
546 STRDUP_ALLOCA (dir, directory);
548 /* If the first character of dir is '/', skip it (and thus enable
549 creation of absolute-pathname directories. */
550 for (i = (*dir == '/'); 1; ++i)
552 for (; dir[i] && dir[i] != '/'; i++)
557 /* Check whether the directory already exists. Allow creation of
558 of intermediate directories to fail, as the initial path components
559 are not necessarily directories! */
560 if (!file_exists_p (dir))
561 ret = mkdir (dir, 0777);
572 /* Merge BASE with FILE. BASE can be a directory or a file name, FILE
573 should be a file name.
575 file_merge("/foo/bar", "baz") => "/foo/baz"
576 file_merge("/foo/bar/", "baz") => "/foo/bar/baz"
577 file_merge("foo", "bar") => "bar"
579 In other words, it's a simpler and gentler version of uri_merge_1. */
582 file_merge (const char *base, const char *file)
585 const char *cut = (const char *)strrchr (base, '/');
588 return xstrdup (file);
590 result = (char *)xmalloc (cut - base + 1 + strlen (file) + 1);
591 memcpy (result, base, cut - base);
592 result[cut - base] = '/';
593 strcpy (result + (cut - base) + 1, file);
598 static int in_acclist PARAMS ((const char *const *, const char *, int));
600 /* Determine whether a file is acceptable to be followed, according to
601 lists of patterns to accept/reject. */
603 acceptable (const char *s)
607 while (l && s[l] != '/')
614 return (in_acclist ((const char *const *)opt.accepts, s, 1)
615 && !in_acclist ((const char *const *)opt.rejects, s, 1));
617 return in_acclist ((const char *const *)opt.accepts, s, 1);
619 else if (opt.rejects)
620 return !in_acclist ((const char *const *)opt.rejects, s, 1);
624 /* Compare S1 and S2 frontally; S2 must begin with S1. E.g. if S1 is
625 `/something', frontcmp() will return 1 only if S2 begins with
626 `/something'. Otherwise, 0 is returned. */
628 frontcmp (const char *s1, const char *s2)
630 for (; *s1 && *s2 && (*s1 == *s2); ++s1, ++s2);
634 /* Iterate through STRLIST, and return the first element that matches
635 S, through wildcards or front comparison (as appropriate). */
637 proclist (char **strlist, const char *s, enum accd flags)
641 for (x = strlist; *x; x++)
642 if (has_wildcards_p (*x))
644 if (fnmatch (*x, s, FNM_PATHNAME) == 0)
649 char *p = *x + ((flags & ALLABS) && (**x == '/')); /* Remove '/' */
656 /* Returns whether DIRECTORY is acceptable for download, wrt the
657 include/exclude lists.
659 If FLAGS is ALLABS, the leading `/' is ignored in paths; relative
660 and absolute paths may be freely intermixed. */
662 accdir (const char *directory, enum accd flags)
664 /* Remove starting '/'. */
665 if (flags & ALLABS && *directory == '/')
669 if (!proclist (opt.includes, directory, flags))
674 if (proclist (opt.excludes, directory, flags))
680 /* Return non-zero if STRING ends with TAIL. For instance:
682 match_tail ("abc", "bc", 0) -> 1
683 match_tail ("abc", "ab", 0) -> 0
684 match_tail ("abc", "abc", 0) -> 1
686 If FOLD_CASE_P is non-zero, the comparison will be
690 match_tail (const char *string, const char *tail, int fold_case_p)
694 /* We want this to be fast, so we code two loops, one with
695 case-folding, one without. */
699 for (i = strlen (string), j = strlen (tail); i >= 0 && j >= 0; i--, j--)
700 if (string[i] != tail[j])
705 for (i = strlen (string), j = strlen (tail); i >= 0 && j >= 0; i--, j--)
706 if (TOLOWER (string[i]) != TOLOWER (tail[j]))
710 /* If the tail was exhausted, the match was succesful. */
717 /* Checks whether string S matches each element of ACCEPTS. A list
718 element are matched either with fnmatch() or match_tail(),
719 according to whether the element contains wildcards or not.
721 If the BACKWARD is 0, don't do backward comparison -- just compare
724 in_acclist (const char *const *accepts, const char *s, int backward)
726 for (; *accepts; accepts++)
728 if (has_wildcards_p (*accepts))
730 /* fnmatch returns 0 if the pattern *does* match the
732 if (fnmatch (*accepts, s, 0) == 0)
739 if (match_tail (s, *accepts, 0))
744 if (!strcmp (s, *accepts))
752 /* Return the location of STR's suffix (file extension). Examples:
753 suffix ("foo.bar") -> "bar"
754 suffix ("foo.bar.baz") -> "baz"
755 suffix ("/foo/bar") -> NULL
756 suffix ("/foo.bar/baz") -> NULL */
758 suffix (const char *str)
762 for (i = strlen (str); i && str[i] != '/' && str[i] != '.'; i--)
766 return (char *)str + i;
771 /* Return non-zero if S contains globbing wildcards (`*', `?', `[' or
775 has_wildcards_p (const char *s)
778 if (*s == '*' || *s == '?' || *s == '[' || *s == ']')
783 /* Return non-zero if FNAME ends with a typical HTML suffix. The
784 following (case-insensitive) suffixes are presumed to be HTML files:
788 ?html (`?' matches one character)
790 #### CAVEAT. This is not necessarily a good indication that FNAME
791 refers to a file that contains HTML! */
793 has_html_suffix_p (const char *fname)
797 if ((suf = suffix (fname)) == NULL)
799 if (!strcasecmp (suf, "html"))
801 if (!strcasecmp (suf, "htm"))
803 if (suf[0] && !strcasecmp (suf + 1, "html"))
808 /* Read a line from FP and return the pointer to freshly allocated
809 storage. The storage space is obtained through malloc() and should
810 be freed with free() when it is no longer needed.
812 The length of the line is not limited, except by available memory.
813 The newline character at the end of line is retained. The line is
814 terminated with a zero character.
816 After end-of-file is encountered without anything being read, NULL
817 is returned. NULL is also returned on error. To distinguish
818 between these two cases, use the stdio function ferror(). */
821 read_whole_line (FILE *fp)
825 char *line = (char *)xmalloc (bufsize);
827 while (fgets (line + length, bufsize - length, fp))
829 length += strlen (line + length);
831 /* Possible for example when reading from a binary file where
832 a line begins with \0. */
835 if (line[length - 1] == '\n')
838 /* fgets() guarantees to read the whole line, or to use up the
839 space we've given it. We can double the buffer
842 line = xrealloc (line, bufsize);
844 if (length == 0 || ferror (fp))
849 if (length + 1 < bufsize)
850 /* Relieve the memory from our exponential greediness. We say
851 `length + 1' because the terminating \0 is not included in
852 LENGTH. We don't need to zero-terminate the string ourselves,
853 though, because fgets() does that. */
854 line = xrealloc (line, length + 1);
858 /* Read FILE into memory. A pointer to `struct file_memory' are
859 returned; use struct element `content' to access file contents, and
860 the element `length' to know the file length. `content' is *not*
861 zero-terminated, and you should *not* read or write beyond the [0,
862 length) range of characters.
864 After you are done with the file contents, call read_file_free to
867 Depending on the operating system and the type of file that is
868 being read, read_file() either mmap's the file into memory, or
869 reads the file into the core using read().
871 If file is named "-", fileno(stdin) is used for reading instead.
872 If you want to read from a real file named "-", use "./-" instead. */
875 read_file (const char *file)
878 struct file_memory *fm;
880 int inhibit_close = 0;
882 /* Some magic in the finest tradition of Perl and its kin: if FILE
883 is "-", just use stdin. */
888 /* Note that we don't inhibit mmap() in this case. If stdin is
889 redirected from a regular file, mmap() will still work. */
892 fd = open (file, O_RDONLY);
895 fm = xnew (struct file_memory);
900 if (fstat (fd, &buf) < 0)
902 fm->length = buf.st_size;
903 /* NOTE: As far as I know, the callers of this function never
904 modify the file text. Relying on this would enable us to
905 specify PROT_READ and MAP_SHARED for a marginal gain in
906 efficiency, but at some cost to generality. */
907 fm->content = mmap (NULL, fm->length, PROT_READ | PROT_WRITE,
909 if (fm->content == (char *)MAP_FAILED)
919 /* The most common reason why mmap() fails is that FD does not point
920 to a plain file. However, it's also possible that mmap() doesn't
921 work for a particular type of file. Therefore, whenever mmap()
922 fails, we just fall back to the regular method. */
923 #endif /* HAVE_MMAP */
926 size = 512; /* number of bytes fm->contents can
927 hold at any given time. */
928 fm->content = xmalloc (size);
932 if (fm->length > size / 2)
934 /* #### I'm not sure whether the whole exponential-growth
935 thing makes sense with kernel read. On Linux at least,
936 read() refuses to read more than 4K from a file at a
937 single chunk anyway. But other Unixes might optimize it
938 better, and it doesn't *hurt* anything, so I'm leaving
941 /* Normally, we grow SIZE exponentially to make the number
942 of calls to read() and realloc() logarithmic in relation
943 to file size. However, read() can read an amount of data
944 smaller than requested, and it would be unreasonable to
945 double SIZE every time *something* was read. Therefore,
946 we double SIZE only when the length exceeds half of the
947 entire allocated size. */
949 fm->content = xrealloc (fm->content, size);
951 nread = read (fd, fm->content + fm->length, size - fm->length);
953 /* Successful read. */
964 if (size > fm->length && fm->length != 0)
965 /* Due to exponential growth of fm->content, the allocated region
966 might be much larger than what is actually needed. */
967 fm->content = xrealloc (fm->content, fm->length);
979 /* Release the resources held by FM. Specifically, this calls
980 munmap() or xfree() on fm->content, depending whether mmap or
981 malloc/read were used to read in the file. It also frees the
982 memory needed to hold the FM structure itself. */
985 read_file_free (struct file_memory *fm)
990 munmap (fm->content, fm->length);
1000 /* Free the pointers in a NULL-terminated vector of pointers, then
1001 free the pointer itself. */
1003 free_vec (char **vec)
1014 /* Append vector V2 to vector V1. The function frees V2 and
1015 reallocates V1 (thus you may not use the contents of neither
1016 pointer after the call). If V1 is NULL, V2 is returned. */
1018 merge_vecs (char **v1, char **v2)
1028 /* To avoid j == 0 */
1033 for (i = 0; v1[i]; i++);
1035 for (j = 0; v2[j]; j++);
1036 /* Reallocate v1. */
1037 v1 = (char **)xrealloc (v1, (i + j + 1) * sizeof (char **));
1038 memcpy (v1 + i, v2, (j + 1) * sizeof (char *));
1043 /* A set of simple-minded routines to store strings in a linked list.
1044 This used to also be used for searching, but now we have hash
1047 /* It's a shame that these simple things like linked lists and hash
1048 tables (see hash.c) need to be implemented over and over again. It
1049 would be nice to be able to use the routines from glib -- see
1050 www.gtk.org for details. However, that would make Wget depend on
1051 glib, and I want to avoid dependencies to external libraries for
1052 reasons of convenience and portability (I suspect Wget is more
1053 portable than anything ever written for Gnome). */
1055 /* Append an element to the list. If the list has a huge number of
1056 elements, this can get slow because it has to find the list's
1057 ending. If you think you have to call slist_append in a loop,
1058 think about calling slist_prepend() followed by slist_nreverse(). */
1061 slist_append (slist *l, const char *s)
1063 slist *newel = xnew (slist);
1066 newel->string = xstrdup (s);
1071 /* Find the last element. */
1078 /* Prepend S to the list. Unlike slist_append(), this is O(1). */
1081 slist_prepend (slist *l, const char *s)
1083 slist *newel = xnew (slist);
1084 newel->string = xstrdup (s);
1089 /* Destructively reverse L. */
1092 slist_nreverse (slist *l)
1097 slist *next = l->next;
1105 /* Is there a specific entry in the list? */
1107 slist_contains (slist *l, const char *s)
1109 for (; l; l = l->next)
1110 if (!strcmp (l->string, s))
1115 /* Free the whole slist. */
1117 slist_free (slist *l)
1128 /* Sometimes it's useful to create "sets" of strings, i.e. special
1129 hash tables where you want to store strings as keys and merely
1130 query for their existence. Here is a set of utility routines that
1131 makes that transparent. */
1134 string_set_add (struct hash_table *ht, const char *s)
1136 /* First check whether the set element already exists. If it does,
1137 do nothing so that we don't have to free() the old element and
1138 then strdup() a new one. */
1139 if (hash_table_contains (ht, s))
1142 /* We use "1" as value. It provides us a useful and clear arbitrary
1143 value, and it consumes no memory -- the pointers to the same
1144 string "1" will be shared by all the key-value pairs in all `set'
1146 hash_table_put (ht, xstrdup (s), "1");
1149 /* Synonym for hash_table_contains... */
1152 string_set_contains (struct hash_table *ht, const char *s)
1154 return hash_table_contains (ht, s);
1158 string_set_free_mapper (void *key, void *value_ignored, void *arg_ignored)
1165 string_set_free (struct hash_table *ht)
1167 hash_table_map (ht, string_set_free_mapper, NULL);
1168 hash_table_destroy (ht);
1172 free_keys_and_values_mapper (void *key, void *value, void *arg_ignored)
1179 /* Another utility function: call free() on all keys and values of HT. */
1182 free_keys_and_values (struct hash_table *ht)
1184 hash_table_map (ht, free_keys_and_values_mapper, NULL);
1188 /* Engine for legible and legible_large_int; add thousand separators
1189 to numbers printed in strings. */
1192 legible_1 (const char *repr)
1194 static char outbuf[48];
1199 /* Reset the pointers. */
1203 /* Ignore the sign for the purpose of adding thousand
1210 /* How many digits before the first separator? */
1211 mod = strlen (inptr) % 3;
1213 for (i = 0; i < mod; i++)
1214 *outptr++ = inptr[i];
1215 /* Now insert the rest of them, putting separator before every
1217 for (i1 = i, i = 0; inptr[i1]; i++, i1++)
1219 if (i % 3 == 0 && i1 != 0)
1221 *outptr++ = inptr[i1];
1223 /* Zero-terminate the string. */
1228 /* Legible -- return a static pointer to the legibly printed wgint. */
1234 /* Print the number into the buffer. */
1235 number_to_string (inbuf, l);
1236 return legible_1 (inbuf);
1239 /* Write a string representation of LARGE_INT NUMBER into the provided
1240 buffer. The buffer should be able to accept 24 characters,
1241 including the terminating zero.
1243 It would be dangerous to use sprintf, because the code wouldn't
1244 work on a machine with gcc-provided long long support, but without
1245 libc support for "%lld". However, such platforms will typically
1246 not have snprintf and will use our version, which does support
1247 "%lld" where long longs are available. */
1250 large_int_to_string (char *buffer, LARGE_INT number)
1252 snprintf (buffer, 24, LARGE_INT_FMT, number);
1255 /* The same as legible(), but works on LARGE_INT. */
1258 legible_large_int (LARGE_INT l)
1261 large_int_to_string (inbuf, l);
1262 return legible_1 (inbuf);
1265 /* Count the digits in an integer number. */
1267 numdigit (wgint number)
1275 while ((number /= 10) > 0)
1280 #define ONE_DIGIT(figure) *p++ = n / (figure) + '0'
1281 #define ONE_DIGIT_ADVANCE(figure) (ONE_DIGIT (figure), n %= (figure))
1283 #define DIGITS_1(figure) ONE_DIGIT (figure)
1284 #define DIGITS_2(figure) ONE_DIGIT_ADVANCE (figure); DIGITS_1 ((figure) / 10)
1285 #define DIGITS_3(figure) ONE_DIGIT_ADVANCE (figure); DIGITS_2 ((figure) / 10)
1286 #define DIGITS_4(figure) ONE_DIGIT_ADVANCE (figure); DIGITS_3 ((figure) / 10)
1287 #define DIGITS_5(figure) ONE_DIGIT_ADVANCE (figure); DIGITS_4 ((figure) / 10)
1288 #define DIGITS_6(figure) ONE_DIGIT_ADVANCE (figure); DIGITS_5 ((figure) / 10)
1289 #define DIGITS_7(figure) ONE_DIGIT_ADVANCE (figure); DIGITS_6 ((figure) / 10)
1290 #define DIGITS_8(figure) ONE_DIGIT_ADVANCE (figure); DIGITS_7 ((figure) / 10)
1291 #define DIGITS_9(figure) ONE_DIGIT_ADVANCE (figure); DIGITS_8 ((figure) / 10)
1292 #define DIGITS_10(figure) ONE_DIGIT_ADVANCE (figure); DIGITS_9 ((figure) / 10)
1294 /* DIGITS_<11-20> are only used on machines with 64-bit numbers. */
1296 #define DIGITS_11(figure) ONE_DIGIT_ADVANCE (figure); DIGITS_10 ((figure) / 10)
1297 #define DIGITS_12(figure) ONE_DIGIT_ADVANCE (figure); DIGITS_11 ((figure) / 10)
1298 #define DIGITS_13(figure) ONE_DIGIT_ADVANCE (figure); DIGITS_12 ((figure) / 10)
1299 #define DIGITS_14(figure) ONE_DIGIT_ADVANCE (figure); DIGITS_13 ((figure) / 10)
1300 #define DIGITS_15(figure) ONE_DIGIT_ADVANCE (figure); DIGITS_14 ((figure) / 10)
1301 #define DIGITS_16(figure) ONE_DIGIT_ADVANCE (figure); DIGITS_15 ((figure) / 10)
1302 #define DIGITS_17(figure) ONE_DIGIT_ADVANCE (figure); DIGITS_16 ((figure) / 10)
1303 #define DIGITS_18(figure) ONE_DIGIT_ADVANCE (figure); DIGITS_17 ((figure) / 10)
1304 #define DIGITS_19(figure) ONE_DIGIT_ADVANCE (figure); DIGITS_18 ((figure) / 10)
1306 /* It is annoying that we have three different syntaxes for 64-bit constants:
1307 - nnnL for 64-bit systems, where they are of type long;
1308 - nnnLL for 32-bit systems that support long long;
1309 - nnnI64 for MS compiler on Windows, which doesn't support long long. */
1312 /* If long is large enough, use long constants. */
1313 # define C10000000000 10000000000L
1314 # define C100000000000 100000000000L
1315 # define C1000000000000 1000000000000L
1316 # define C10000000000000 10000000000000L
1317 # define C100000000000000 100000000000000L
1318 # define C1000000000000000 1000000000000000L
1319 # define C10000000000000000 10000000000000000L
1320 # define C100000000000000000 100000000000000000L
1321 # define C1000000000000000000 1000000000000000000L
1323 # if SIZEOF_LONG_LONG != 0
1324 /* Otherwise, if long long is available, use long long constants. */
1325 # define C10000000000 10000000000LL
1326 # define C100000000000 100000000000LL
1327 # define C1000000000000 1000000000000LL
1328 # define C10000000000000 10000000000000LL
1329 # define C100000000000000 100000000000000LL
1330 # define C1000000000000000 1000000000000000LL
1331 # define C10000000000000000 10000000000000000LL
1332 # define C100000000000000000 100000000000000000LL
1333 # define C1000000000000000000 1000000000000000000LL
1335 # if defined(WINDOWS)
1336 /* Use __int64 constants under Windows. */
1337 # define C10000000000 10000000000I64
1338 # define C100000000000 100000000000I64
1339 # define C1000000000000 1000000000000I64
1340 # define C10000000000000 10000000000000I64
1341 # define C100000000000000 100000000000000I64
1342 # define C1000000000000000 1000000000000000I64
1343 # define C10000000000000000 10000000000000000I64
1344 # define C100000000000000000 100000000000000000I64
1345 # define C1000000000000000000 1000000000000000000I64
1350 /* SPRINTF_WGINT is used by number_to_string to handle pathological
1351 cases and to portably support strange sizes of wgint. */
1352 #if SIZEOF_LONG >= SIZEOF_WGINT
1353 # define SPRINTF_WGINT(buf, n) sprintf(buf, "%ld", (long) (n))
1355 # if SIZEOF_LONG_LONG >= SIZEOF_WGINT
1356 # define SPRINTF_WGINT(buf, n) sprintf(buf, "%lld", (long long) (n))
1359 # define SPRINTF_WGINT(buf, n) sprintf(buf, "%I64", (__int64) (n))
1364 /* Print NUMBER to BUFFER in base 10. This is equivalent to
1365 `sprintf(buffer, "%lld", (long long) number)', only much faster and
1366 portable to machines without long long.
1368 The speedup may make a difference in programs that frequently
1369 convert numbers to strings. Some implementations of sprintf,
1370 particularly the one in GNU libc, have been known to be extremely
1371 slow when converting integers to strings.
1373 Return the pointer to the location where the terminating zero was
1374 printed. (Equivalent to calling buffer+strlen(buffer) after the
1377 BUFFER should be big enough to accept as many bytes as you expect
1378 the number to take up. On machines with 64-bit longs the maximum
1379 needed size is 24 bytes. That includes the digits needed for the
1380 largest 64-bit number, the `-' sign in case it's negative, and the
1381 terminating '\0'. */
1384 number_to_string (char *buffer, wgint number)
1389 #if (SIZEOF_WGINT != 4) && (SIZEOF_WGINT != 8)
1390 /* We are running in a strange or misconfigured environment. Let
1391 sprintf cope with it. */
1392 SPRINTF_WGINT (buffer, n);
1393 p += strlen (buffer);
1394 #else /* (SIZEOF_WGINT == 4) || (SIZEOF_WGINT == 8) */
1400 /* We cannot print a '-' and assign -n to n because -n would
1401 overflow. Let sprintf deal with this border case. */
1402 SPRINTF_WGINT (buffer, n);
1403 p += strlen (buffer);
1411 if (n < 10) { DIGITS_1 (1); }
1412 else if (n < 100) { DIGITS_2 (10); }
1413 else if (n < 1000) { DIGITS_3 (100); }
1414 else if (n < 10000) { DIGITS_4 (1000); }
1415 else if (n < 100000) { DIGITS_5 (10000); }
1416 else if (n < 1000000) { DIGITS_6 (100000); }
1417 else if (n < 10000000) { DIGITS_7 (1000000); }
1418 else if (n < 100000000) { DIGITS_8 (10000000); }
1419 else if (n < 1000000000) { DIGITS_9 (100000000); }
1420 #if SIZEOF_WGINT == 4
1421 /* wgint is four bytes long: we're done. */
1422 /* ``if (1)'' serves only to preserve editor indentation. */
1423 else if (1) { DIGITS_10 (1000000000); }
1425 /* wgint is 64 bits long -- make sure to process all the digits. */
1426 else if (n < C10000000000) { DIGITS_10 (1000000000); }
1427 else if (n < C100000000000) { DIGITS_11 (C10000000000); }
1428 else if (n < C1000000000000) { DIGITS_12 (C100000000000); }
1429 else if (n < C10000000000000) { DIGITS_13 (C1000000000000); }
1430 else if (n < C100000000000000) { DIGITS_14 (C10000000000000); }
1431 else if (n < C1000000000000000) { DIGITS_15 (C100000000000000); }
1432 else if (n < C10000000000000000) { DIGITS_16 (C1000000000000000); }
1433 else if (n < C100000000000000000) { DIGITS_17 (C10000000000000000); }
1434 else if (n < C1000000000000000000) { DIGITS_18 (C100000000000000000); }
1435 else { DIGITS_19 (C1000000000000000000); }
1439 #endif /* (SIZEOF_WGINT == 4) || (SIZEOF_WGINT == 8) */
1445 #undef ONE_DIGIT_ADVANCE
1469 /* Print NUMBER to a statically allocated string and return a pointer
1470 to the printed representation.
1472 This function is intended to be used in conjunction with printf.
1473 It is hard to portably print wgint values:
1474 a) you cannot use printf("%ld", number) because wgint can be long
1475 long on 32-bit machines with LFS.
1476 b) you cannot use printf("%lld", number) because NUMBER could be
1477 long on 32-bit machines without LFS, or on 64-bit machines,
1478 which do not require LFS. Also, Windows doesn't support %lld.
1479 c) you cannot use printf("%j", (int_max_t) number) because not all
1480 versions of printf support "%j", the most notable being the one
1482 d) you cannot #define WGINT_FMT to the appropriate format and use
1483 printf(WGINT_FMT, number) because that would break translations
1484 for user-visible messages, such as printf("Downloaded: %d
1487 What you should use instead is printf("%s", number_to_static_string
1490 CAVEAT: since the function returns pointers to static data, you
1491 must be careful to copy its result before calling it again.
1492 However, to make it more useful with printf, the function maintains
1493 an internal ring of static buffers to return. That way things like
1494 printf("%s %s", number_to_static_string (num1),
1495 number_to_static_string (num2)) work as expected. Three buffers
1496 are currently used, which means that "%s %s %s" will work, but "%s
1497 %s %s %s" won't. If you need to print more than three wgints,
1498 bump the RING_SIZE (or rethink your message.) */
1501 number_to_static_string (wgint number)
1503 static char ring[RING_SIZE][24];
1505 char *buf = ring[ringpos];
1506 number_to_string (buf, number);
1507 ringpos = (ringpos + 1) % RING_SIZE;
1511 /* Support for timers. */
1513 #undef TIMER_WINDOWS
1514 #undef TIMER_GETTIMEOFDAY
1517 /* Depending on the OS and availability of gettimeofday(), one and
1518 only one of the above constants will be defined. Virtually all
1519 modern Unix systems will define TIMER_GETTIMEOFDAY; Windows will
1520 use TIMER_WINDOWS. TIMER_TIME is a catch-all method for
1521 non-Windows systems without gettimeofday.
1523 #### Perhaps we should also support ftime(), which exists on old
1524 BSD 4.2-influenced systems? (It also existed under MS DOS Borland
1525 C, if memory serves me.) */
1528 # define TIMER_WINDOWS
1529 #else /* not WINDOWS */
1530 # ifdef HAVE_GETTIMEOFDAY
1531 # define TIMER_GETTIMEOFDAY
1535 #endif /* not WINDOWS */
1537 #ifdef TIMER_GETTIMEOFDAY
1538 typedef struct timeval wget_sys_time;
1542 typedef time_t wget_sys_time;
1545 #ifdef TIMER_WINDOWS
1546 typedef ULARGE_INTEGER wget_sys_time;
1550 /* Whether the start time has been initialized. */
1553 /* The starting point in time which, subtracted from the current
1554 time, yields elapsed time. */
1555 wget_sys_time start;
1557 /* The most recent elapsed time, calculated by wtimer_elapsed().
1558 Measured in milliseconds. */
1559 double elapsed_last;
1561 /* Approximately, the time elapsed between the true start of the
1562 measurement and the time represented by START. */
1563 double elapsed_pre_start;
1566 /* Allocate a timer. Calling wtimer_read on the timer will return
1567 zero. It is not legal to call wtimer_update with a freshly
1568 allocated timer -- use wtimer_reset first. */
1571 wtimer_allocate (void)
1573 struct wget_timer *wt = xnew (struct wget_timer);
1578 /* Allocate a new timer and reset it. Return the new timer. */
1583 struct wget_timer *wt = wtimer_allocate ();
1588 /* Free the resources associated with the timer. Its further use is
1592 wtimer_delete (struct wget_timer *wt)
1597 /* Store system time to WST. */
1600 wtimer_sys_set (wget_sys_time *wst)
1602 #ifdef TIMER_GETTIMEOFDAY
1603 gettimeofday (wst, NULL);
1610 #ifdef TIMER_WINDOWS
1611 /* We use GetSystemTime to get the elapsed time. MSDN warns that
1612 system clock adjustments can skew the output of GetSystemTime
1613 when used as a timer and gives preference to GetTickCount and
1614 high-resolution timers. But GetTickCount can overflow, and hires
1615 timers are typically used for profiling, not for regular time
1616 measurement. Since we handle clock skew anyway, we just use
1620 GetSystemTime (&st);
1622 /* As recommended by MSDN, we convert SYSTEMTIME to FILETIME, copy
1623 FILETIME to ULARGE_INTEGER, and use regular 64-bit integer
1624 arithmetic on that. */
1625 SystemTimeToFileTime (&st, &ft);
1626 wst->HighPart = ft.dwHighDateTime;
1627 wst->LowPart = ft.dwLowDateTime;
1631 /* Reset timer WT. This establishes the starting point from which
1632 wtimer_elapsed() will return the number of elapsed milliseconds.
1633 It is allowed to reset a previously used timer.
1635 If a non-zero value is used as START, the timer's values will be
1639 wtimer_reset (struct wget_timer *wt)
1641 /* Set the start time to the current time. */
1642 wtimer_sys_set (&wt->start);
1643 wt->elapsed_last = 0;
1644 wt->elapsed_pre_start = 0;
1645 wt->initialized = 1;
1649 wtimer_sys_diff (wget_sys_time *wst1, wget_sys_time *wst2)
1651 #ifdef TIMER_GETTIMEOFDAY
1652 return ((double)(wst1->tv_sec - wst2->tv_sec) * 1000
1653 + (double)(wst1->tv_usec - wst2->tv_usec) / 1000);
1657 return 1000 * (*wst1 - *wst2);
1661 /* VC++ 6 doesn't support direct cast of uint64 to double. To work
1662 around this, we subtract, then convert to signed, then finally to
1664 return (double)(signed __int64)(wst1->QuadPart - wst2->QuadPart) / 10000;
1668 /* Update the timer's elapsed interval. This function causes the
1669 timer to call gettimeofday (or time(), etc.) to update its idea of
1670 current time. To get the elapsed interval in milliseconds, use
1673 This function handles clock skew, i.e. time that moves backwards is
1677 wtimer_update (struct wget_timer *wt)
1682 assert (wt->initialized != 0);
1684 wtimer_sys_set (&now);
1685 elapsed = wt->elapsed_pre_start + wtimer_sys_diff (&now, &wt->start);
1687 /* Ideally we'd just return the difference between NOW and
1688 wt->start. However, the system timer can be set back, and we
1689 could return a value smaller than when we were last called, even
1690 a negative value. Both of these would confuse the callers, which
1691 expect us to return monotonically nondecreasing values.
1693 Therefore: if ELAPSED is smaller than its previous known value,
1694 we reset wt->start to the current time and effectively start
1695 measuring from this point. But since we don't want the elapsed
1696 value to start from zero, we set elapsed_pre_start to the last
1697 elapsed time and increment all future calculations by that
1700 if (elapsed < wt->elapsed_last)
1703 wt->elapsed_pre_start = wt->elapsed_last;
1704 elapsed = wt->elapsed_last;
1707 wt->elapsed_last = elapsed;
1710 /* Return the elapsed time in milliseconds between the last call to
1711 wtimer_reset and the last call to wtimer_update.
1713 A typical use of the timer interface would be:
1715 struct wtimer *timer = wtimer_new ();
1716 ... do something that takes a while ...
1718 double msecs = wtimer_read (); */
1721 wtimer_read (const struct wget_timer *wt)
1723 return wt->elapsed_last;
1726 /* Return the assessed granularity of the timer implementation, in
1727 milliseconds. This is used by code that tries to substitute a
1728 better value for timers that have returned zero. */
1731 wtimer_granularity (void)
1733 #ifdef TIMER_GETTIMEOFDAY
1734 /* Granularity of gettimeofday varies wildly between architectures.
1735 However, it appears that on modern machines it tends to be better
1736 than 1ms. Assume 100 usecs. (Perhaps the configure process
1737 could actually measure this?) */
1745 #ifdef TIMER_WINDOWS
1746 /* According to MSDN, GetSystemTime returns a broken-down time
1747 structure the smallest member of which are milliseconds. */
1752 /* This should probably be at a better place, but it doesn't really
1753 fit into html-parse.c. */
1755 /* The function returns the pointer to the malloc-ed quoted version of
1756 string s. It will recognize and quote numeric and special graphic
1757 entities, as per RFC1866:
1765 No other entities are recognized or replaced. */
1767 html_quote_string (const char *s)
1773 /* Pass through the string, and count the new size. */
1774 for (i = 0; *s; s++, i++)
1777 i += 4; /* `amp;' */
1778 else if (*s == '<' || *s == '>')
1779 i += 3; /* `lt;' and `gt;' */
1780 else if (*s == '\"')
1781 i += 5; /* `quot;' */
1785 res = (char *)xmalloc (i + 1);
1787 for (p = res; *s; s++)
1800 *p++ = (*s == '<' ? 'l' : 'g');
1827 /* Determine the width of the terminal we're running on. If that's
1828 not possible, return 0. */
1831 determine_screen_width (void)
1833 /* If there's a way to get the terminal size using POSIX
1834 tcgetattr(), somebody please tell me. */
1839 if (opt.lfilename != NULL)
1842 fd = fileno (stderr);
1843 if (ioctl (fd, TIOCGWINSZ, &wsz) < 0)
1844 return 0; /* most likely ENOTTY */
1847 #else /* not TIOCGWINSZ */
1849 CONSOLE_SCREEN_BUFFER_INFO csbi;
1850 if (!GetConsoleScreenBufferInfo (GetStdHandle (STD_ERROR_HANDLE), &csbi))
1852 return csbi.dwSize.X;
1853 # else /* neither WINDOWS nor TIOCGWINSZ */
1855 #endif /* neither WINDOWS nor TIOCGWINSZ */
1856 #endif /* not TIOCGWINSZ */
1859 /* Return a random number between 0 and MAX-1, inclusive.
1861 If MAX is greater than the value of RAND_MAX+1 on the system, the
1862 returned value will be in the range [0, RAND_MAX]. This may be
1863 fixed in a future release.
1865 The random number generator is seeded automatically the first time
1868 This uses rand() for portability. It has been suggested that
1869 random() offers better randomness, but this is not required for
1870 Wget, so I chose to go for simplicity and use rand
1873 DO NOT use this for cryptographic purposes. It is only meant to be
1874 used in situations where quality of the random numbers returned
1875 doesn't really matter. */
1878 random_number (int max)
1886 srand (time (NULL));
1891 /* On systems that don't define RAND_MAX, assume it to be 2**15 - 1,
1892 and enforce that assumption by masking other bits. */
1894 # define RAND_MAX 32767
1898 /* This is equivalent to rand() % max, but uses the high-order bits
1899 for better randomness on architecture where rand() is implemented
1900 using a simple congruential generator. */
1902 bounded = (double)max * rnd / (RAND_MAX + 1.0);
1903 return (int)bounded;
1906 /* Return a random uniformly distributed floating point number in the
1907 [0, 1) range. The precision of returned numbers is 9 digits.
1909 Modify this to use erand48() where available! */
1914 /* We can't rely on any specific value of RAND_MAX, but I'm pretty
1915 sure it's greater than 1000. */
1916 int rnd1 = random_number (1000);
1917 int rnd2 = random_number (1000);
1918 int rnd3 = random_number (1000);
1919 return rnd1 / 1000.0 + rnd2 / 1000000.0 + rnd3 / 1000000000.0;
1923 /* A debugging function for checking whether an MD5 library works. */
1925 #include "gen-md5.h"
1928 debug_test_md5 (char *buf)
1930 unsigned char raw[16];
1931 static char res[33];
1935 ALLOCA_MD5_CONTEXT (ctx);
1938 gen_md5_update ((unsigned char *)buf, strlen (buf), ctx);
1939 gen_md5_finish (ctx, raw);
1946 *p2++ = XNUM_TO_digit (*p1 >> 4);
1947 *p2++ = XNUM_TO_digit (*p1 & 0xf);
1956 /* Implementation of run_with_timeout, a generic timeout-forcing
1957 routine for systems with Unix-like signal handling. */
1959 #ifdef USE_SIGNAL_TIMEOUT
1960 # ifdef HAVE_SIGSETJMP
1961 # define SETJMP(env) sigsetjmp (env, 1)
1963 static sigjmp_buf run_with_timeout_env;
1966 abort_run_with_timeout (int sig)
1968 assert (sig == SIGALRM);
1969 siglongjmp (run_with_timeout_env, -1);
1971 # else /* not HAVE_SIGSETJMP */
1972 # define SETJMP(env) setjmp (env)
1974 static jmp_buf run_with_timeout_env;
1977 abort_run_with_timeout (int sig)
1979 assert (sig == SIGALRM);
1980 /* We don't have siglongjmp to preserve the set of blocked signals;
1981 if we longjumped out of the handler at this point, SIGALRM would
1982 remain blocked. We must unblock it manually. */
1983 int mask = siggetmask ();
1984 mask &= ~sigmask (SIGALRM);
1987 /* Now it's safe to longjump. */
1988 longjmp (run_with_timeout_env, -1);
1990 # endif /* not HAVE_SIGSETJMP */
1992 /* Arrange for SIGALRM to be delivered in TIMEOUT seconds. This uses
1993 setitimer where available, alarm otherwise.
1995 TIMEOUT should be non-zero. If the timeout value is so small that
1996 it would be rounded to zero, it is rounded to the least legal value
1997 instead (1us for setitimer, 1s for alarm). That ensures that
1998 SIGALRM will be delivered in all cases. */
2001 alarm_set (double timeout)
2004 /* Use the modern itimer interface. */
2005 struct itimerval itv;
2007 itv.it_value.tv_sec = (long) timeout;
2008 itv.it_value.tv_usec = 1000000L * (timeout - (long)timeout);
2009 if (itv.it_value.tv_sec == 0 && itv.it_value.tv_usec == 0)
2010 /* Ensure that we wait for at least the minimum interval.
2011 Specifying zero would mean "wait forever". */
2012 itv.it_value.tv_usec = 1;
2013 setitimer (ITIMER_REAL, &itv, NULL);
2014 #else /* not ITIMER_REAL */
2015 /* Use the old alarm() interface. */
2016 int secs = (int) timeout;
2018 /* Round TIMEOUTs smaller than 1 to 1, not to zero. This is
2019 because alarm(0) means "never deliver the alarm", i.e. "wait
2020 forever", which is not what someone who specifies a 0.5s
2021 timeout would expect. */
2024 #endif /* not ITIMER_REAL */
2027 /* Cancel the alarm set with alarm_set. */
2033 struct itimerval disable;
2035 setitimer (ITIMER_REAL, &disable, NULL);
2036 #else /* not ITIMER_REAL */
2038 #endif /* not ITIMER_REAL */
2041 /* Call FUN(ARG), but don't allow it to run for more than TIMEOUT
2042 seconds. Returns non-zero if the function was interrupted with a
2043 timeout, zero otherwise.
2045 This works by setting up SIGALRM to be delivered in TIMEOUT seconds
2046 using setitimer() or alarm(). The timeout is enforced by
2047 longjumping out of the SIGALRM handler. This has several
2048 advantages compared to the traditional approach of relying on
2049 signals causing system calls to exit with EINTR:
2051 * The callback function is *forcibly* interrupted after the
2052 timeout expires, (almost) regardless of what it was doing and
2053 whether it was in a syscall. For example, a calculation that
2054 takes a long time is interrupted as reliably as an IO
2057 * It works with both SYSV and BSD signals because it doesn't
2058 depend on the default setting of SA_RESTART.
2060 * It doesn't special handler setup beyond a simple call to
2061 signal(). (It does use sigsetjmp/siglongjmp, but they're
2064 The only downside is that, if FUN allocates internal resources that
2065 are normally freed prior to exit from the functions, they will be
2066 lost in case of timeout. */
2069 run_with_timeout (double timeout, void (*fun) (void *), void *arg)
2079 signal (SIGALRM, abort_run_with_timeout);
2080 if (SETJMP (run_with_timeout_env) != 0)
2082 /* Longjumped out of FUN with a timeout. */
2083 signal (SIGALRM, SIG_DFL);
2086 alarm_set (timeout);
2089 /* Preserve errno in case alarm() or signal() modifies it. */
2090 saved_errno = errno;
2092 signal (SIGALRM, SIG_DFL);
2093 errno = saved_errno;
2098 #else /* not USE_SIGNAL_TIMEOUT */
2101 /* A stub version of run_with_timeout that just calls FUN(ARG). Don't
2102 define it under Windows, because Windows has its own version of
2103 run_with_timeout that uses threads. */
2106 run_with_timeout (double timeout, void (*fun) (void *), void *arg)
2111 #endif /* not WINDOWS */
2112 #endif /* not USE_SIGNAL_TIMEOUT */
2116 /* Sleep the specified amount of seconds. On machines without
2117 nanosleep(), this may sleep shorter if interrupted by signals. */
2120 xsleep (double seconds)
2122 #ifdef HAVE_NANOSLEEP
2123 /* nanosleep is the preferred interface because it offers high
2124 accuracy and, more importantly, because it allows us to reliably
2125 restart after having been interrupted by a signal such as
2127 struct timespec sleep, remaining;
2128 sleep.tv_sec = (long) seconds;
2129 sleep.tv_nsec = 1000000000L * (seconds - (long) seconds);
2130 while (nanosleep (&sleep, &remaining) < 0 && errno == EINTR)
2131 /* If nanosleep has been interrupted by a signal, adjust the
2132 sleeping period and return to sleep. */
2134 #else /* not HAVE_NANOSLEEP */
2136 /* If usleep is available, use it in preference to select. */
2139 /* On some systems, usleep cannot handle values larger than
2140 1,000,000. If the period is larger than that, use sleep
2141 first, then add usleep for subsecond accuracy. */
2143 seconds -= (long) seconds;
2145 usleep (seconds * 1000000L);
2146 #else /* not HAVE_USLEEP */
2148 struct timeval sleep;
2149 sleep.tv_sec = (long) seconds;
2150 sleep.tv_usec = 1000000L * (seconds - (long) seconds);
2151 select (0, NULL, NULL, NULL, &sleep);
2152 /* If select returns -1 and errno is EINTR, it means we were
2153 interrupted by a signal. But without knowing how long we've
2154 actually slept, we can't return to sleep. Using gettimeofday to
2155 track sleeps is slow and unreliable due to clock skew. */
2156 #else /* not HAVE_SELECT */
2158 #endif /* not HAVE_SELECT */
2159 #endif /* not HAVE_USLEEP */
2160 #endif /* not HAVE_NANOSLEEP */
2163 #endif /* not WINDOWS */