return '\0';
}
\f
-/* Return the URL as fine-formed string, with a proper protocol, port
- number, directory and optional user/password. If HIDE is non-zero,
- password will be hidden. The forbidden characters in the URL will
- be cleansed. */
+/* Return the URL as fine-formed string, with a proper protocol,
+ optional port number, directory and optional user/password. If
+ HIDE is non-zero, password will be hidden. The forbidden
+ characters in the URL will be cleansed. */
char *
str_url (const struct urlinfo *u, int hide)
{
{
char *tmp = (char *)xmalloc (strlen (dir) + 3);
/*sprintf (tmp, "%%2F%s", dir + 1);*/
- *tmp = '%';
+ tmp[0] = '%';
tmp[1] = '2';
tmp[2] = 'F';
strcpy (tmp + 3, dir + 1);
return name;
}
-/* Like strlen(), except if `?' is present in the URL and its protocol
- is HTTP, act as if `?' is the end of the string. Needed for the
- correct implementation of `construct' below, at least until we code
- up proper parsing of URLs. */
+/* Like strlen(), but allow the URL to be ended with '?'. */
static int
-urllen_http_hack (const char *url)
+urlpath_length (const char *url)
{
- if ((!strncmp (url, "http://", 7)
- || !strncmp (url, "https://", 7)))
- {
- const char *q = strchr (url, '?');
- if (q)
- return q - url;
- }
+ const char *q = strchr (url, '?');
+ if (q)
+ return q - url;
return strlen (url);
}
+static const char *
+find_last_char (const char *b, const char *e, char c)
+{
+ for (; e > b; e--)
+ if (*e == c)
+ return e;
+ return NULL;
+}
+
/* Construct an absolute URL, given a (possibly) relative one. This
- is more tricky than it might seem, but it works. */
+ gets tricky if you want to cover all the "reasonable" cases, but
+ I'm satisfied with the result. */
static char *
construct (const char *url, const char *sub, int subsize, int no_proto)
{
if (no_proto)
{
- int i;
+ const char *end = url + urlpath_length (url);
if (*sub != '/')
{
- for (i = urllen_http_hack (url); i && url[i] != '/'; i--);
- if (!i || (url[i] == url[i - 1]))
+ /* SUB is a relative URL: we need to replace everything
+ after last slash (possibly empty) with SUB.
+
+ So, if URL is "whatever/foo/bar", and SUB is "qux/xyzzy",
+ our result should be "whatever/foo/qux/xyzzy". */
+ int need_explicit_slash = 0;
+ int span;
+ const char *start_insert;
+ const char *last_slash = find_last_char (url, end, '/'); /* the last slash. */
+ if (!last_slash)
{
- int l = urllen_http_hack (url);
- char *t = (char *)alloca (l + 2);
- memcpy (t, url, l);
- t[l] = '/';
- t[l + 1] = '\0';
- url = t;
- i = l;
+ /* No slash found at all. Append SUB to what we have,
+ but we'll need a slash as a separator.
+
+ Example: if url == "foo" and sub == "qux/xyzzy", then
+ we cannot just append sub to url, because we'd get
+ "fooqux/xyzzy", whereas what we want is
+ "foo/qux/xyzzy".
+
+ To make sure the / gets inserted, we set
+ need_explicit_slash to 1. We also set start_insert
+ to end + 1, so that the length calculations work out
+ correctly for one more (slash) character. Accessing
+ that character is fine, since it will be the
+ delimiter, '\0' or '?'. */
+ /* example: "foo?..." */
+ /* ^ ('?' gets changed to '/') */
+ start_insert = end + 1;
+ need_explicit_slash = 1;
}
- constr = (char *)xmalloc (i + 1 + subsize + 1);
- strncpy (constr, url, i + 1);
- constr[i + 1] = '\0';
- strncat (constr, sub, subsize);
+ else
+ {
+ /* example: "whatever/foo/bar" */
+ /* ^ */
+ start_insert = last_slash + 1;
+ }
+
+ span = start_insert - url;
+ constr = (char *)xmalloc (span + subsize + 1);
+ if (span)
+ memcpy (constr, url, span);
+ if (need_explicit_slash)
+ constr[span - 1] = '/';
+ if (subsize)
+ memcpy (constr + span, sub, subsize);
+ constr[span + subsize] = '\0';
}
else /* *sub == `/' */
{
- int fl;
-
- i = 0;
- do
- {
- for (; url[i] && url[i] != '/'; i++);
- if (!url[i])
- break;
- fl = (url[i] == url[i + 1] && url[i + 1] == '/');
- if (fl)
- i += 2;
- }
- while (fl);
- if (!url[i])
- {
- int l = urllen_http_hack (url);
- char *t = (char *)alloca (l + 2);
- strcpy (t, url);
- t[l] = '/';
- t[l + 1] = '\0';
- url = t;
- }
- constr = (char *)xmalloc (i + 1 + subsize + 1);
- strncpy (constr, url, i);
- constr[i] = '\0';
- strncat (constr + i, sub, subsize);
- constr[i + subsize] = '\0';
- } /* *sub == `/' */
+ /* SUB is an absolute path: we need to replace everything
+ after (and including) the FIRST slash with SUB.
+
+ So, if URL is "http://host/whatever/foo/bar", and SUB is
+ "/qux/xyzzy", our result should be
+ "http://host/qux/xyzzy". */
+ int span;
+ const char *slash, *start_insert;
+ const char *pos = url;
+ int seen_slash_slash = 0;
+ /* We're looking for the first slash, but want to ignore
+ double slash. */
+ again:
+ slash = memchr (pos, '/', end - pos);
+ if (slash && !seen_slash_slash)
+ if (*(slash + 1) == '/')
+ {
+ pos = slash + 2;
+ seen_slash_slash = 1;
+ goto again;
+ }
+
+ /* At this point, SLASH is the location of the first / after
+ "//", or the first slash altogether. START_INSERT is the
+ pointer to the location where SUB will be inserted. When
+ examining the last two examples, keep in mind that SUB
+ begins with '/'. */
+
+ if (!slash && !seen_slash_slash)
+ /* example: "foo" */
+ /* ^ */
+ start_insert = url;
+ else if (!slash && seen_slash_slash)
+ /* example: "http://foo" */
+ /* ^ */
+ start_insert = end;
+ else if (slash && !seen_slash_slash)
+ /* example: "foo/bar" */
+ /* ^ */
+ start_insert = url;
+ else if (slash && seen_slash_slash)
+ /* example: "http://something/" */
+ /* ^ */
+ start_insert = slash;
+
+ span = start_insert - url;
+ constr = (char *)xmalloc (span + subsize + 1);
+ if (span)
+ memcpy (constr, url, span);
+ if (subsize)
+ memcpy (constr + span, sub, subsize);
+ constr[span + subsize] = '\0';
+ }
}
else /* !no_proto */
{
- constr = (char *)xmalloc (subsize + 1);
- strncpy (constr, sub, subsize);
- constr[subsize] = '\0';
+ constr = strdupdelim (sub, sub + subsize);
}
return constr;
}
projects / wget / commitdiff