logprintf (LOG_VERBOSE, "%d-%d\n", to_file_count, to_url_count);
}
-/* Construct and return a link that points from S1's position to S2.
- Both files should be local file names, S1 of the referrering file,
- and S2 of the referred file.
+/* Construct and return a link that points from BASEFILE to LINKFILE.
+ Both files should be local file names, BASEFILE of the referrering
+ file, and LINKFILE of the referred file.
- So, if S1 is "H/index.html" and S2 is "H/images/news.gif", this
- function will return "images/news.gif". On the other hand, if S1
- is "H/ioccc/index.html", and S2 is "H/images/fly.gif", it will
- return "../images/fly.gif".
+ Examples:
- Caveats: S1 should not begin with `/', unless S2 also begins with
- '/'. S1 should not contain things like ".." and such --
- construct_relative ("fly/ioccc/../index.html",
- "fly/images/fly.gif") will fail. (A workaround is to call
- something like path_simplify() on S1). */
+ cr("foo", "bar") -> "bar"
+ cr("A/foo", "A/bar") -> "bar"
+ cr("A/foo", "A/B/bar") -> "B/bar"
+ cr("A/X/foo", "A/Y/bar") -> "../Y/bar"
+ cr("X/", "Y/bar") -> "../Y/bar" (trailing slash does matter in BASE)
+
+ Both files should be absolute or relative, otherwise strange
+ results might ensue. The function makes no special efforts to
+ handle "." and ".." in links, so make sure they're not there
+ (e.g. using path_simplify). */
static char *
-construct_relative (const char *s1, const char *s2)
+construct_relative (const char *basefile, const char *linkfile)
{
- int i, cnt, sepdirs1;
- char *res;
+ char *link;
+ int basedirs;
+ const char *b, *l;
+ int i, start;
+
+ /* First, skip the initial directory components common to both
+ files. */
+ start = 0;
+ for (b = basefile, l = linkfile; *b == *l && *b != '\0'; ++b, ++l)
+ {
+ if (*b == '/')
+ start = (b - basefile) + 1;
+ }
+ basefile += start;
+ linkfile += start;
+
+ /* With common directories out of the way, the situation we have is
+ as follows:
+ b - b1/b2/[...]/bfile
+ l - l1/l2/[...]/lfile
- i = cnt = 0;
- /* Skip the directories common to both strings. */
- while (1)
+ The link we're constructing needs to be:
+ lnk - ../../l1/l2/[...]/lfile
+
+ Where the number of ".."'s equals the number of bN directory
+ components in B. */
+
+ /* Count the directory components in B. */
+ basedirs = 0;
+ for (b = basefile; *b; b++)
{
- while (s1[i] && s2[i]
- && (s1[i] == s2[i])
- && (s1[i] != '/')
- && (s2[i] != '/'))
- ++i;
- if (s1[i] == '/' && s2[i] == '/')
- cnt = ++i;
- else
- break;
+ if (*b == '/')
+ ++basedirs;
}
- for (sepdirs1 = 0; s1[i]; i++)
- if (s1[i] == '/')
- ++sepdirs1;
- /* Now, construct the file as of:
- - ../ repeated sepdirs1 time
- - all the non-mutual directories of S2. */
- res = (char *)xmalloc (3 * sepdirs1 + strlen (s2 + cnt) + 1);
- for (i = 0; i < sepdirs1; i++)
- memcpy (res + 3 * i, "../", 3);
- strcpy (res + 3 * i, s2 + cnt);
- return res;
+
+ /* Construct LINK as explained above. */
+ link = (char *)xmalloc (3 * basedirs + strlen (linkfile) + 1);
+ for (i = 0; i < basedirs; i++)
+ memcpy (link + 3 * i, "../", 3);
+ strcpy (link + 3 * i, linkfile);
+ return link;
}
static void