static cell AMX_NATIVE_CALL replace_stringex(AMX *amx, cell *params)
{
int len;
size_t maxlength = (size_t)params[2];
char *text = get_amxstring(amx, params[1], 0, len);
const char *search = get_amxstring(amx, params[3], 1, len);
const char *replace = get_amxstring(amx, params[4], 2, len);
size_t searchLen = (params[5] == -1) ? strlen(search) : (size_t)params[5];
size_t replaceLen = (params[6] == -1) ? strlen(replace) : (size_t)params[6];
bool caseSensitive = params[7] ? true : false;
if (searchLen == 0)
{
LogError(amx, AMX_ERR_NATIVE, "Cannot replace searches of empty strings.");
return -1;
}
char *ptr = UTIL_ReplaceEx(text, maxlength + 1, search, searchLen, replace, replaceLen, caseSensitive); // + EOS
if (ptr == NULL)
{
return -1;
}
set_amxstring(amx, params[1], ptr, maxlength);
return ptr - text;
}
unsigned int UTIL_ReplaceAll(char *subject, size_t maxlength, const char *search, const char *replace)
{
size_t searchLen = strlen(search);
size_t replaceLen = strlen(replace);
char *ptr = subject;
unsigned int total = 0;
while ((ptr = UTIL_ReplaceEx(ptr, maxlength, search, searchLen, replace, replaceLen)) != NULL)
{
total++;
if (*ptr == '\0')
{
break;
}
}
return total;
}
int RegEx::Replace(char *text, size_t textMaxLen, const char *replace, size_t replaceLen, int flags)
{
char *output = text;
/**
* Retrieve all matches and store them in
* mSubStrings list.
*/
if (MatchAll(output) == -1)
{
return -1;
}
size_t subjectLen = strlen(subject);
size_t total = 0;
size_t baseIndex = 0;
size_t diffLength = 0;
char *toReplace = new char[textMaxLen + 1];
char *toSearch = NULL;
/**
* All characters which is not matched are not copied when replacing matches.
* Then original text (output buffer) should be considerated as empty.
*/
if (flags & REGEX_FORMAT_NOCOPY)
{
*output = '\0';
}
else
{
/**
* This is used only when we do replace matches.
*/
toSearch = new char[textMaxLen + 1];
}
/**
* Loop over all matches found.
*/
for (size_t i = 0; i < mMatchesSubs.length(); ++i)
{
char *ptr = toReplace;
size_t browsed = 0;
size_t searchLen = 0;
size_t length = 0;
/**
* Build the replace string as it can contain backreference
* and this needs to be parsed.
*/
for (const char *s = replace, *end = s + replaceLen; s < end && browsed <= textMaxLen; ++s, ++browsed)
{
unsigned int c = *s;
/**
* Supported format specifiers:
*
* $number : Substitutes the substring matched by group number.
* n must be an integer value designating a valid backreference, greater than 0, and of two digits at most.
* ${name} : Substitutes the substring matched by the named group name (a maximum of 32 characters).
* $& : Substitutes a copy of the whole match.
* $` : Substitutes all the text of the input string before the match.
* $' : Substitutes all the text of the input string after the match.
* $+ : Substitutes the last group that was captured.
* $_ : Substitutes the entire input string.
* $$ : Substitutes a literal "$".
*/
if (c == '$' || c == '\\')
{
switch (*++s)
{
case '\0':
{
/**
* End of string.
* Copy one character.
*/
*(ptr + browsed) = c;
break;
}
case '&':
{
/**
* Concatenate retrieved full match sub-string.
* length - 1 to overwrite EOS.
*/
GetSubstring(baseIndex, ptr + browsed, textMaxLen, &length);
browsed += length - 1;
break;
}
case '`':
{
/**
* Concatenate part of original text up to
* first sub-string position.
*/
length = mSubStrings.at(baseIndex).start;
memcpy(ptr + browsed, subject, length);
browsed += length - 1;
break;
}
case '\'':
{
/**
* Concatenate part of original text from
* last sub-string end position to EOS.
*/
length = mSubStrings.at(baseIndex).end;
memcpy(ptr + browsed, subject + length, subjectLen - length);
browsed += (subjectLen - length) - 1;
break;
}
case '+':
{
/**
* Copy the last group that was captured.
*/
GetSubstring(baseIndex + mMatchesSubs.at(i) - 1, ptr + browsed, textMaxLen, &length);
browsed += length - 1;
break;
}
case '_':
{
/**
* Copy the entire input string.
*/
memcpy(ptr + browsed, subject, subjectLen);
browsed += (subjectLen - 1);
break;
}
case '$':
case '\\':
{
/**
* Copy the single character $ or \.
*/
*(ptr + browsed) = c;
break;
}
case '0': case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9':
case '{':
{
/**
* Checking backreference.
* Which can be either $n, ${n} or ${name}.
*/
int backref = -1;
const char *walk = s;
bool inBrace = false;
bool nameCheck = false;
/**
* ${nn}.
* ^
*/
if (*walk == '{')
{
inBrace = true;
++walk;
}
/**
* Valid number.
* $nn or ${nn}
* ^ ^
*/
if (*walk >= '0' && *walk <= '9')
{
backref = *walk - '0';
++walk;
}
else if (inBrace)
{
nameCheck = true;
/**
* Not a valid number.
* Checking as string.
* ${name}
* ^
*/
if (*walk)
{
const char *pch = strchr(walk, '}');
if (pch != NULL)
{
/**
* A named group maximum character is 32 (PCRE).
*/
char name[32];
size_t nameLength = strncopy(name, walk, pch - walk + 1);
int flags, num = 0;
pcre_fullinfo(re, NULL, PCRE_INFO_OPTIONS, &flags);
/**
* If PCRE_DUPNAMES is set, the pcre_copy_named_substring function should be used
* as pcre_get_stringnumber output order is not defined.
*/
if (flags & PCRE_DUPNAMES)
{
memset(ovector, 0, REGEX_MAX_SUBPATTERNS);
/**
* pcre_copy_named_substring needs a vector containing sub-patterns ranges
* for a given match.
*/
for (size_t j = 0; j < mMatchesSubs.at(i); ++j)
{
ovector[2 * j] = mSubStrings.at(baseIndex + j).start;
ovector[2 * j + 1] = mSubStrings.at(baseIndex + j).end;
}
num = pcre_copy_named_substring(re, subject, ovector, mMatchesSubs.at(i), name, ptr + browsed, (int)textMaxLen);
if (num != PCRE_ERROR_NOSUBSTRING)
{
browsed += num - 1;
s = pch;
break;
}
++pch;
}
else
{
/**
* Retrieve sub-pattern index from a give name.
*/
num = pcre_get_stringnumber(re, name);
if (num != PCRE_ERROR_NOSUBSTRING)
{
backref = num;
walk = ++pch;
}
}
if (num == PCRE_ERROR_NOSUBSTRING || num >= (int)mMatchesSubs.at(i))
{
/**
* If a sub-string for a given match is not found, or if > to
* number of sub-patterns we still need to check if this
* group name is a valid one because if so we want to escape it.
* Looking at the name table.
*/
bool found = false;
for (size_t i = 0; i < mSubsNameTable.length(); ++i)
{
if (!mSubsNameTable.at(i).name.compare(name))
{
--browsed;
s = --pch;
found = true;
break;
}
}
if (found)
{
continue;
}
}
}
}
}
if (!nameCheck)
{
/**
* Valid second number.
* $nn or ${nn}
* ^ ^
*/
if (*walk && *walk >= '0' && *walk <= '9')
{
backref = backref * 10 + *walk - '0';
++walk;
}
if (inBrace)
{
/**
* Invalid specifier
* Either hit EOS or missing }.
* ${n or ${nn or ${nx or ${nnx
* ^ ^ ^ ^
*/
if (*walk == '\0' || *walk != '}')
{
backref = -1;
}
else
{
++walk;
}
}
}
length = walk - s;
s = --walk;
/**
* We can't provide a capture number >= to total that pcre_exec has found.
* 0 is implicitly accepted, same behavior as $&.
*/
if (backref >= 0 && backref < mNumSubpatterns)
{
/**
* Valid available index for a given match.
*/
if ((size_t)backref < mMatchesSubs.at(i))
{
/**
* Concatenate retrieved sub-string.
* length - 1 to overwrite EOS.
*/
GetSubstring(baseIndex + backref, ptr + browsed, textMaxLen, &length);
browsed += length - 1;
}
else
{
/**
* Valid unavailable index for a given match.
*/
--browsed;
}
}
else
{
/**
* If we here it means the syntax is valid but sub-pattern doesn't exist.
* So, copy as it is, including $.
*/
memcpy(ptr + browsed, s - length, length + 1);
browsed += length;
}
break;
}
default:
{
/**
* Not a valid format modifier.
* So we copy characters as it is.
*/
*(ptr + browsed) = *s;
break;
}
}
}
else
{
/**
* At this point, direct copy.
*/
*(ptr + browsed) = c;
}
}
*(ptr + browsed) = '\0';
/**
* Concatenate only replace string of each match,
* as we don't want to copy unmatched characters.
*/
if (flags & REGEX_FORMAT_NOCOPY)
{
/**
* We want just the first occurrence.
*/
if (total++ && (flags & REGEX_FORMAT_FIRSTONLY))
{
break;
}
strncat(output, toReplace, textMaxLen + 1);
}
else
{
/**
* Retrieves full string of a given match.
*/
const char *search = GetSubstring(baseIndex, toSearch, textMaxLen, &searchLen);
/**
* We get something to replace, but the sub-pattern to search is empty.
* We insert replacement either a the start end or string.
*/
if (*toReplace && !searchLen)
{
if (output - text > 0)
{
strncat(output, toReplace, textMaxLen);
}
else
{
strncat(toReplace, text, textMaxLen);
strncopy(text, toReplace, strlen(toReplace) + 1);
}
++total;
}
else if ((output = UTIL_ReplaceEx(text + mSubStrings.at(baseIndex).start + diffLength, textMaxLen, search, searchLen, toReplace, browsed, false)) != NULL)
{
/**
* Then we simply do a replace.
* Probably not the most efficient, but this should be at least safe.
* To avoid issue where the function could find a string which is not at the expected index,
* We force the input string to start from index of the full match.
*/
++total;
}
if (total && (flags & REGEX_FORMAT_FIRSTONLY))
{
break;
}
}
/**
* mMatchesSubs is a flat list containing all sub-patterns of all matches.
* A number of sub-patterns can vary per match. So we calculate the position in the list,
* from where the first sub-pattern result of current match starts.
*/
baseIndex += mMatchesSubs.at(i);
diffLength += browsed - searchLen;
}
delete[] toReplace;
if (toSearch != NULL)
{
delete[] toSearch;
}
/**
* Return the number of successful replacements.
*/
return total;
}