path: root/src/common/strlib.c

// Copyright (c) Hercules Dev Team, licensed under GNU GPL.
// See the LICENSE file
// Portions Copyright (c) Athena Dev Teams

#define HERCULES_CORE

#include "strlib.h"

#include "common/cbasetypes.h"
#include "common/malloc.h"
#include "common/showmsg.h"

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>

#define J_MAX_MALLOC_SIZE 65535

struct strlib_interface strlib_s;
struct stringbuf_interface stringbuf_s;
struct sv_interface sv_s;

struct strlib_interface *strlib;
struct stringbuf_interface *StrBuf;
struct sv_interface *sv;

// escapes a string in-place (' -> \' , \ -> \\ , % -> _)
char* jstrescape (char* pt) {
	//copy from here
	char *ptr;
	int i = 0, j = 0;

	//copy string to temporary
	CREATE(ptr, char, J_MAX_MALLOC_SIZE);
	strcpy(ptr,pt);

	while (ptr[i] != '\0') {
		switch (ptr[i]) {
			case '\'':
				pt[j++] = '\\';
				pt[j++] = ptr[i++];
				break;
			case '\\':
				pt[j++] = '\\';
				pt[j++] = ptr[i++];
				break;
			case '%':
				pt[j++] = '_'; i++;
				break;
			default:
				pt[j++] = ptr[i++];
		}
	}
	pt[j++] = '\0';
	aFree(ptr);
	return pt;
}

// escapes a string into a provided buffer
char* jstrescapecpy (char* pt, const char* spt)
{
	//copy from here
	//WARNING: Target string pt should be able to hold strlen(spt)*2, as each time
	//a escape character is found, the target's final length increases! [Skotlex]
	int i =0, j=0;

	if (!spt) {
		//Return an empty string [Skotlex]
		pt[0] = '\0';
		return &pt[0];
	}

	while (spt[i] != '\0') {
		switch (spt[i]) {
			case '\'':
				pt[j++] = '\\';
				pt[j++] = spt[i++];
				break;
			case '\\':
				pt[j++] = '\\';
				pt[j++] = spt[i++];
				break;
			case '%':
				pt[j++] = '_'; i++;
				break;
			default:
				pt[j++] = spt[i++];
		}
	}
	pt[j++] = '\0';
	return &pt[0];
}

// escapes exactly 'size' bytes of a string into a provided buffer
int jmemescapecpy (char* pt, const char* spt, int size)
{
	//copy from here
	int i =0, j=0;

	while (i < size) {
		switch (spt[i]) {
			case '\'':
				pt[j++] = '\\';
				pt[j++] = spt[i++];
				break;
			case '\\':
				pt[j++] = '\\';
				pt[j++] = spt[i++];
				break;
			case '%':
				pt[j++] = '_'; i++;
				break;
			default:
				pt[j++] = spt[i++];
		}
	}
	// copy size is 0 ~ (j-1)
	return j;
}

// Function to suppress control characters in a string.
int strlib_remove_control_chars(char *str)
{
	int i;
	int change = 0;

	for(i = 0; str[i]; i++) {
		if (ISCNTRL(str[i])) {
			str[i] = '_';
			change = 1;
		}
	}

	return change;
}

// Removes characters identified by ISSPACE from the start and end of the string
// NOTE: make sure the string is not const!!
char *strlib_trim(char *str)
{
	size_t start;
	size_t end;

	if( str == NULL )
		return str;

	// get start position
	for( start = 0; str[start] && ISSPACE(str[start]); ++start )
		;
	// get end position
	for( end = strlen(str); start < end && str[end-1] && ISSPACE(str[end-1]); --end )
		;
	// trim
	if( start == end )
		*str = '\0';// empty string
	else
	{// move string with null-terminator
		str[end] = '\0';
		memmove(str,str+start,end-start+1);
	}
	return str;
}

// Converts one or more consecutive occurrences of the delimiters into a single space
// and removes such occurrences from the beginning and end of string
// NOTE: make sure the string is not const!!
char *strlib_normalize_name(char *str, const char *delims)
{
	char* in = str;
	char* out = str;
	int put_space = 0;

	if( str == NULL || delims == NULL )
		return str;

	// trim start of string
	while( *in && strchr(delims,*in) )
		++in;
	while( *in )
	{
		if( put_space )
		{// replace trim characters with a single space
			*out = ' ';
			++out;
		}
		// copy non trim characters
		while( *in && !strchr(delims,*in) )
		{
			*out = *in;
			++out;
			++in;
		}
		// skip trim characters
		while( *in && strchr(delims,*in) )
			++in;
		put_space = 1;
	}
	*out = '\0';
	return str;
}

//stristr: Case insensitive version of strstr, code taken from
//http://www.daniweb.com/code/snippet313.html, Dave Sinkula
//
const char *strlib_stristr(const char *haystack, const char *needle)
{
	if ( !*needle )
	{
		return haystack;
	}
	for ( ; *haystack; ++haystack )
	{
		if ( TOUPPER(*haystack) == TOUPPER(*needle) )
		{
			// matched starting char -- loop through remaining chars
			const char *h, *n;
			for ( h = haystack, n = needle; *h && *n; ++h, ++n )
			{
				if ( TOUPPER(*h) != TOUPPER(*n) )
				{
					break;
				}
			}
			if ( !*n ) // matched all of 'needle' to null termination
			{
				return haystack; // return the start of the match
			}
		}
	}
	return 0;
}

char* strlib_strtok_r(char *s1, const char *s2, char **lasts)
{
#ifdef __WIN32
	char *ret;

	if (s1 == NULL)
		s1 = *lasts;
	while(*s1 && strchr(s2, *s1))
		++s1;
	if(*s1 == '\0')
		return NULL;
	ret = s1;
	while(*s1 && !strchr(s2, *s1))
		++s1;
	if(*s1)
		*s1++ = '\0';
	*lasts = s1;
	return ret;
#else
	return strtok_r(s1, s2, lasts);
#endif
}

size_t strlib_strnlen(const char *string, size_t maxlen)
{
// TODO: The _MSC_VER check can probably be removed (we no longer support VS
// versions <= 2003, do we?), but this implementation might be still necessary
// for NetBSD 5.x and possibly some Solaris versions.
#if !(defined(WIN32) && defined(_MSC_VER) && _MSC_VER >= 1400) && !defined(HAVE_STRNLEN)
/* Find the length of STRING, but scan at most MAXLEN characters.
 * If no '\0' terminator is found in that many characters, return MAXLEN.
 */
	const char* end = (const char*)memchr(string, '\0', maxlen);
	return end ? (size_t) (end - string) : maxlen;
#else
	return strnlen(string, maxlen);
#endif
}

//----------------------------------------------------
// E-mail check: return 0 (not correct) or 1 (valid).
//----------------------------------------------------
int strlib_e_mail_check(char *email)
{
	char ch;
	char* last_arobas;
	size_t len = strlen(email);

	// athena limits
	if (len < 3 || len > 39)
		return 0;

	// part of RFC limits (official reference of e-mail description)
	if (strchr(email, '@') == NULL || email[len-1] == '@')
		return 0;

	if (email[len-1] == '.')
		return 0;

	last_arobas = strrchr(email, '@');

	if (strstr(last_arobas, "@.") != NULL || strstr(last_arobas, "..") != NULL)
		return 0;

	for(ch = 1; ch < 32; ch++)
		if (strchr(last_arobas, ch) != NULL)
			return 0;

	if (strchr(last_arobas, ' ') != NULL || strchr(last_arobas, ';') != NULL)
		return 0;

	// all correct
	return 1;
}

//--------------------------------------------------
// Return numerical value of a switch configuration
// on/off, yes/no, true/false, number
//--------------------------------------------------
int strlib_config_switch(const char *str) {
	size_t len = strlen(str);
	if ((len == 2 && strcmpi(str, "on") == 0)
	 || (len == 3 && strcmpi(str, "yes") == 0)
	 || (len == 4 && strcmpi(str, "true") == 0)
	// || (len == 3 && strcmpi(str, "oui") == 0) // Uncomment and edit to add your own localized versions
	)
		return 1;

	if ((len == 3 && strcmpi(str, "off") == 0)
	 || (len == 2 && strcmpi(str, "no") == 0)
	 || (len == 5 && strcmpi(str, "false") == 0)
	// || (len == 3 && strcmpi(str, "non") == 0) // Uncomment and edit to add your own localized versions
	)
		return 0;

	return (int)strtol(str, NULL, 0);
}

/// strncpy that always null-terminates the string
char *strlib_safestrncpy(char *dst, const char *src, size_t n)
{
	if( n > 0 )
	{
		char* d = dst;
		const char* s = src;
		d[--n] = '\0';/* null-terminate string */
		for( ; n > 0; --n )
		{
			if( (*d++ = *s++) == '\0' )
			{/* null-pad remaining bytes */
				while( --n > 0 )
					*d++ = '\0';
				break;
			}
		}
	}
	return dst;
}

/// doesn't crash on null pointer
size_t strlib_safestrnlen(const char *string, size_t maxlen)
{
	return ( string != NULL ) ? strnlen(string, maxlen) : 0;
}

/// Works like snprintf, but always null-terminates the buffer.
/// Returns the size of the string (without null-terminator)
/// or -1 if the buffer is too small.
///
/// @param buf Target buffer
/// @param sz Size of the buffer (including null-terminator)
/// @param fmt Format string
/// @param ... Format arguments
/// @return The size of the string or -1 if the buffer is too small
int strlib_safesnprintf(char *buf, size_t sz, const char *fmt, ...) __attribute__((format(printf, 3, 4)));
int strlib_safesnprintf(char *buf, size_t sz, const char *fmt, ...)
{
	va_list ap;
	int ret;

	va_start(ap,fmt);
	ret = vsnprintf(buf, sz, fmt, ap);
	va_end(ap);
	if (ret < 0 || (size_t)ret >= sz) { // overflow
		buf[sz-1] = '\0';// always null-terminate
		return -1;
	}
	return ret;
}

/// Returns the line of the target position in the string.
/// Lines start at 1.
int strlib_strline(const char *str, size_t pos)
{
	const char* target;
	int line;

	if( str == NULL || pos == 0 )
		return 1;

	target = str+pos;
	for( line = 1; ; ++line )
	{
		str = strchr(str, '\n');
		if( str == NULL || target <= str )
			break;// found target line
		++str;// skip newline
	}
	return line;
}

/// Produces the hexadecimal representation of the given input.
/// The output buffer must be at least count*2+1 in size.
/// Returns true on success, false on failure.
///
/// @param output Output string
/// @param input Binary input buffer
/// @param count Number of bytes to convert
bool strlib_bin2hex(char *output, unsigned char *input, size_t count)
{
	char toHex[] = "0123456789abcdef";
	size_t i;

	for( i = 0; i < count; ++i )
	{
		*output++ = toHex[(*input & 0xF0) >> 4];
		*output++ = toHex[(*input & 0x0F) >> 0];
		++input;
	}
	*output = '\0';
	return true;
}

/////////////////////////////////////////////////////////////////////
/// Parses a single field in a delim-separated string.
/// The delimiter after the field is skipped.
///
/// @param svstate Parse state
/// @return 1 if a field was parsed, 0 if already done, -1 on error.
int sv_parse_next(struct s_svstate* svstate)
{
	enum {
		START_OF_FIELD,
		PARSING_FIELD,
		PARSING_C_ESCAPE,
		END_OF_FIELD,
		TERMINATE,
		END
	} state;
	const char* str;
	int len;
	enum e_svopt opt;
	char delim;
	int i;

	if( svstate == NULL )
		return -1;// error

	str = svstate->str;
	len = svstate->len;
	opt = svstate->opt;
	delim = svstate->delim;

	// check opt
	if( delim == '\n' && (opt&(SV_TERMINATE_CRLF|SV_TERMINATE_LF)) )
	{
		ShowError("sv_parse_next: delimiter '\\n' is not compatible with options SV_TERMINATE_LF or SV_TERMINATE_CRLF.\n");
		return -1;// error
	}
	if( delim == '\r' && (opt&(SV_TERMINATE_CRLF|SV_TERMINATE_CR)) )
	{
		ShowError("sv_parse_next: delimiter '\\r' is not compatible with options SV_TERMINATE_CR or SV_TERMINATE_CRLF.\n");
		return -1;// error
	}

	if( svstate->done || str == NULL )
	{
		svstate->done = true;
		return 0;// nothing to parse
	}

#define IS_END() ( i >= len )
#define IS_DELIM() ( str[i] == delim )
#define IS_TERMINATOR() ( \
	((opt&SV_TERMINATE_LF) && str[i] == '\n') || \
	((opt&SV_TERMINATE_CR) && str[i] == '\r') || \
	((opt&SV_TERMINATE_CRLF) && i+1 < len && str[i] == '\r' && str[i+1] == '\n') )
#define IS_C_ESCAPE() ( (opt&SV_ESCAPE_C) && str[i] == '\\' )
#define SET_FIELD_START() svstate->start = i
#define SET_FIELD_END() svstate->end = i

	i = svstate->off;
	state = START_OF_FIELD;
	while( state != END )
	{
		switch( state )
		{
		case START_OF_FIELD:// record start of field and start parsing it
			SET_FIELD_START();
			state = PARSING_FIELD;
			break;

		case PARSING_FIELD:// skip field character
			if( IS_END() || IS_DELIM() || IS_TERMINATOR() )
				state = END_OF_FIELD;
			else if( IS_C_ESCAPE() )
				state = PARSING_C_ESCAPE;
			else
				++i;// normal character
			break;

		case PARSING_C_ESCAPE:// skip escape sequence (validates it too)
			{
				++i;// '\\'
				if( IS_END() )
				{
					ShowError("sv_parse_next: empty escape sequence\n");
					return -1;
				}
				if( str[i] == 'x' )
				{// hex escape
					++i;// 'x'
					if( IS_END() || !ISXDIGIT(str[i]) )
					{
						ShowError("sv_parse_next: \\x with no following hex digits\n");
						return -1;
					}
					do{
						++i;// hex digit
					}while( !IS_END() && ISXDIGIT(str[i]));
				}
				else if( str[i] == '0' || str[i] == '1' || str[i] == '2' )
				{// octal escape
					++i;// octal digit
					if( !IS_END() && str[i] >= '0' && str[i] <= '7' )
						++i;// octal digit
					if( !IS_END() && str[i] >= '0' && str[i] <= '7' )
						++i;// octal digit
				}
				else if( strchr(SV_ESCAPE_C_SUPPORTED, str[i]) )
				{// supported escape character
					++i;
				}
				else
				{
					ShowError("sv_parse_next: unknown escape sequence \\%c\n", str[i]);
					return -1;
				}
				state = PARSING_FIELD;
				break;
			}

		case END_OF_FIELD:// record end of field and stop
			SET_FIELD_END();
			state = END;
			if( IS_END() )
				;// nothing else
			else if( IS_DELIM() )
				++i;// delim
			else if( IS_TERMINATOR() )
				state = TERMINATE;
			break;

		case TERMINATE:
#if 0
			// skip line terminator
			if( (opt&SV_TERMINATE_CRLF) && i+1 < len && str[i] == '\r' && str[i+1] == '\n' )
				i += 2;// CRLF
			else
				++i;// CR or LF
#endif
			svstate->done = true;
			state = END;
			break;
		}
	}
	if( IS_END() )
		svstate->done = true;
	svstate->off = i;

#undef IS_END
#undef IS_DELIM
#undef IS_TERMINATOR
#undef IS_C_ESCAPE
#undef SET_FIELD_START
#undef SET_FIELD_END

	return 1;
}

/// Parses a delim-separated string.
/// Starts parsing at startoff and fills the pos array with position pairs.
/// out_pos[0] and out_pos[1] are the start and end of line.
/// Other position pairs are the start and end of fields.
/// Returns the number of fields found or -1 if an error occurs.
///
/// out_pos can be NULL.
/// If a line terminator is found, the end position is placed there.
/// out_pos[2] and out_pos[3] for the first field, out_pos[4] and out_pos[5]
/// for the seconds field and so on.
/// Unfilled positions are set to -1.
///
/// @param str String to parse
/// @param len Length of the string
/// @param startoff Where to start parsing
/// @param delim Field delimiter
/// @param out_pos Array of resulting positions
/// @param npos Size of the pos array
/// @param opt Options that determine the parsing behavior
/// @return Number of fields found in the string or -1 if an error occurred
int sv_parse(const char* str, int len, int startoff, char delim, int* out_pos, int npos, enum e_svopt opt) {
	struct s_svstate svstate;
	int count;

	// initialize
	if( out_pos == NULL ) npos = 0;
	for( count = 0; count < npos; ++count )
		out_pos[count] = -1;
	svstate.str = str;
	svstate.len = len;
	svstate.off = startoff;
	svstate.opt = opt;
	svstate.delim = delim;
	svstate.done = false;

	// parse
	count = 0;
	if( npos > 0 ) out_pos[0] = startoff;
	while( !svstate.done ) {
		++count;
		if( sv_parse_next(&svstate) <= 0 )
			return -1;// error
		if( npos > count*2 ) out_pos[count*2] = svstate.start;
		if( npos > count*2+1 ) out_pos[count*2+1] = svstate.end;
	}
	if( npos > 1 ) out_pos[1] = svstate.off;
	return count;
}

/// Splits a delim-separated string.
/// WARNING: this function modifies the input string
/// Starts splitting at startoff and fills the out_fields array.
/// out_fields[0] is the start of the next line.
/// Other entries are the start of fields (null-terminated).
/// Returns the number of fields found or -1 if an error occurs.
///
/// out_fields can be NULL.
/// Fields that don't fit in out_fields are not null-terminated.
/// Extra entries in out_fields are filled with the end of the last field (empty string).
///
/// @param str String to parse
/// @param len Length of the string
/// @param startoff Where to start parsing
/// @param delim Field delimiter
/// @param out_fields Array of resulting fields
/// @param nfields Size of the field array
/// @param opt Options that determine the parsing behavior
/// @return Number of fields found in the string or -1 if an error occurred
int sv_split(char* str, int len, int startoff, char delim, char** out_fields, int nfields, enum e_svopt opt) {
	int pos[1024];
	int i;
	int done;
	char* end;
	int ret = sv_parse(str, len, startoff, delim, pos, ARRAYLENGTH(pos), opt);

	if( ret == -1 || out_fields == NULL || nfields <= 0 )
		return ret; // nothing to do

	// next line
	end = str + pos[1];
	if( end[0] == '\0' ) {
		*out_fields = end;
	} else if( (opt&SV_TERMINATE_LF) && end[0] == '\n' ) {
		if( !(opt&SV_KEEP_TERMINATOR) )
			end[0] = '\0';
		*out_fields = end + 1;
	} else if( (opt&SV_TERMINATE_CRLF) && end[0] == '\r' && end[1] == '\n' ) {
		if( !(opt&SV_KEEP_TERMINATOR) )
			end[0] = end[1] = '\0';
		*out_fields = end + 2;
	} else if( (opt&SV_TERMINATE_CR) && end[0] == '\r' ) {
		if( !(opt&SV_KEEP_TERMINATOR) )
			end[0] = '\0';
		*out_fields = end + 1;
	} else {
		ShowError("sv_split: unknown line delimiter 0x02%x.\n", (unsigned char)end[0]);
		return -1;// error
	}
	++out_fields;
	--nfields;

	// fields
	i = 2;
	done = 0;
	while( done < ret && nfields > 0 ) {
		if( i < ARRAYLENGTH(pos) ) { // split field
			*out_fields = str + pos[i];
			end = str + pos[i+1];
			*end = '\0';
			// next field
			i += 2;
			++done;
			++out_fields;
			--nfields;
		} else { // get more fields
			sv_parse(str, len, pos[i-1] + 1, delim, pos, ARRAYLENGTH(pos), opt);
			i = 2;
		}
	}
	// remaining fields
	for( i = 0; i < nfields; ++i )
		out_fields[i] = end;
	return ret;
}

/// Escapes src to out_dest according to the format of the C compiler.
/// Returns the length of the escaped string.
/// out_dest should be len*4+1 in size.
///
/// @param out_dest Destination buffer
/// @param src Source string
/// @param len Length of the source string
/// @param escapes Extra characters to be escaped
/// @return Length of the escaped string
size_t sv_escape_c(char* out_dest, const char* src, size_t len, const char* escapes) {
	size_t i;
	size_t j;

	if( out_dest == NULL )
		return 0;// nothing to do
	if( src == NULL ) { // nothing to escape
		*out_dest = 0;
		return 0;
	}
	if( escapes == NULL )
		escapes = "";

	for( i = 0, j = 0; i < len; ++i ) {
		switch( src[i] ) {
			case '\0':// octal 0
				out_dest[j++] = '\\';
				out_dest[j++] = '0';
				out_dest[j++] = '0';
				out_dest[j++] = '0';
				break;
			case '\r':// carriage return
				out_dest[j++] = '\\';
				out_dest[j++] = 'r';
				break;
			case '\n':// line feed
				out_dest[j++] = '\\';
				out_dest[j++] = 'n';
				break;
			case '\\':// escape character
				out_dest[j++] = '\\';
				out_dest[j++] = '\\';
				break;
			default:
				if( strchr(escapes,src[i]) ) {// escape
					out_dest[j++] = '\\';
					switch( src[i] ) {
						case '\a': out_dest[j++] = 'a'; break;
						case '\b': out_dest[j++] = 'b'; break;
						case '\t': out_dest[j++] = 't'; break;
						case '\v': out_dest[j++] = 'v'; break;
						case '\f': out_dest[j++] = 'f'; break;
						case '\?': out_dest[j++] = '?'; break;
						default:// to octal
							out_dest[j++] = '0'+((char)(((unsigned char)src[i]&0700)>>6));
							out_dest[j++] = '0'+((char)(((unsigned char)src[i]&0070)>>3));
							out_dest[j++] = '0'+((char)(((unsigned char)src[i]&0007)   ));
							break;
					}
				}
				else
					out_dest[j++] = src[i];
				break;
		}
	}
	out_dest[j] = 0;
	return j;
}

/// Unescapes src to out_dest according to the format of the C compiler.
/// Returns the length of the unescaped string.
/// out_dest should be len+1 in size and can be the same buffer as src.
///
/// @param out_dest Destination buffer
/// @param src Source string
/// @param len Length of the source string
/// @return Length of the escaped string
size_t sv_unescape_c(char* out_dest, const char* src, size_t len) {
	static unsigned char low2hex[256] = {
		0,  0,  0,  0,  0,  0,  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,// 0x0?
		0,  0,  0,  0,  0,  0,  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,// 0x1?
		0,  0,  0,  0,  0,  0,  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,// 0x2?
		0,  1,  2,  3,  4,  5,  6, 7, 8, 9, 0, 0, 0, 0, 0, 0,// 0x3?
		0, 10, 11, 12, 13, 14, 15, 0, 0, 0, 0, 0, 0, 0, 0, 0,// 0x4?
		0,  0,  0,  0,  0,  0,  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,// 0x5?
		0, 10, 11, 12, 13, 14, 15, 0, 0, 0, 0, 0, 0, 0, 0, 0,// 0x6?
		0,  0,  0,  0,  0,  0,  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,// 0x7?
		0,  0,  0,  0,  0,  0,  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,// 0x8?
		0,  0,  0,  0,  0,  0,  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,// 0x9?
		0,  0,  0,  0,  0,  0,  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,// 0xA?
		0,  0,  0,  0,  0,  0,  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,// 0xB?
		0,  0,  0,  0,  0,  0,  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,// 0xC?
		0,  0,  0,  0,  0,  0,  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,// 0xD?
		0,  0,  0,  0,  0,  0,  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,// 0xE?
		0,  0,  0,  0,  0,  0,  0, 0, 0, 0, 0, 0, 0, 0, 0, 0 // 0xF?
	};
	size_t i;
	size_t j;

	for( i = 0, j = 0; i < len; ) {
		if( src[i] == '\\' ) {
			++i;// '\\'
			if( i >= len )
				ShowWarning("sv_unescape_c: empty escape sequence\n");
			else if( src[i] == 'x' ) {// hex escape sequence
				unsigned char c = 0;
				unsigned char inrange = 1;

				++i;// 'x'
				if( i >= len || !ISXDIGIT(src[i]) ) {
					ShowWarning("sv_unescape_c: \\x with no following hex digits\n");
					continue;
				}
				do {
					if( c > 0x0F && inrange ) {
						ShowWarning("sv_unescape_c: hex escape sequence out of range\n");
						inrange = 0;
					}
					c = (c<<4)|low2hex[(unsigned char)src[i]];// hex digit
					++i;
				} while( i < len && ISXDIGIT(src[i]) );
				out_dest[j++] = (char)c;
			} else if( src[i] == '0' || src[i] == '1' || src[i] == '2' || src[i] == '3' ) {// octal escape sequence (255=0377)
				unsigned char c = src[i]-'0';
				++i;// '0', '1', '2' or '3'
				if( i < len && src[i] >= '0' && src[i] <= '7' ) {
					c = (c<<3)|(src[i]-'0');
					++i;// octal digit
				}
				if( i < len && src[i] >= '0' && src[i] <= '7' ) {
					c = (c<<3)|(src[i]-'0');
					++i;// octal digit
				}
				out_dest[j++] = (char)c;
			} else { // other escape sequence
				if( strchr(SV_ESCAPE_C_SUPPORTED, src[i]) == NULL )
					ShowWarning("sv_unescape_c: unknown escape sequence \\%c\n", src[i]);
				switch( src[i] ) {
					case 'a': out_dest[j++] = '\a'; break;
					case 'b': out_dest[j++] = '\b'; break;
					case 't': out_dest[j++] = '\t'; break;
					case 'n': out_dest[j++] = '\n'; break;
					case 'v': out_dest[j++] = '\v'; break;
					case 'f': out_dest[j++] = '\f'; break;
					case 'r': out_dest[j++] = '\r'; break;
					case '?': out_dest[j++] = '\?'; break;
					default: out_dest[j++] = src[i]; break;
				}
				++i;// escaped character
			}
		} else
			out_dest[j++] = src[i++];// normal character
	}
	out_dest[j] = 0;
	return j;
}

/// Skips a C escape sequence (starting with '\\').
const char* skip_escaped_c(const char* p) {
	if( p && *p == '\\' ) {
		++p;
		switch( *p ) {
			case 'x':// hexadecimal
				++p;
				while( ISXDIGIT(*p) )
					++p;
				break;
			case '0':
			case '1':
			case '2':
			case '3':// octal
				++p;
				if( *p >= '0' && *p <= '7' )
					++p;
				if( *p >= '0' && *p <= '7' )
					++p;
				break;
			default:
				if( *p && strchr(SV_ESCAPE_C_SUPPORTED, *p) )
					++p;
		}
	}
	return p;
}

/// Opens and parses a file containing delim-separated columns, feeding them to the specified callback function row by row.
/// Tracks the progress of the operation (current line number, number of successfully processed rows).
/// Returns 'true' if it was able to process the specified file, or 'false' if it could not be read.
///
/// @param directory Directory
/// @param filename File to process
/// @param delim Field delimiter
/// @param mincols Minimum number of columns of a valid row
/// @param maxcols Maximum number of columns of a valid row
/// @param parseproc User-supplied row processing function
/// @return true on success, false if file could not be opened
bool sv_readdb(const char* directory, const char* filename, char delim, int mincols, int maxcols, int maxrows, bool (*parseproc)(char* fields[], int columns, int current)) {
	FILE* fp;
	int lines = 0;
	int entries = 0;
	char** fields; // buffer for fields ([0] is reserved)
	int columns, fields_length;
	char path[1024], line[1024];

	snprintf(path, sizeof(path), "%s/%s", directory, filename);

	// open file
	if( (fp = fopen(path, "r")) == NULL ) {
		ShowError("sv_readdb: can't read %s\n", path);
		return false;
	}

	// allocate enough memory for the maximum requested amount of columns plus the reserved one
	fields_length = maxcols+1;
	fields = (char**)aMalloc(fields_length*sizeof(char*));

	// process rows one by one
	while( fgets(line, sizeof(line), fp) ) {
		char *match;
		lines++;

		if ((match = strstr(line, "//") ) != NULL) {
			// strip comments
			match[0] = 0;
		}

		//TODO: strip trailing whitespace
		if( line[0] == '\0' || line[0] == '\n' || line[0] == '\r')
			continue;

		columns = sv_split(line, (int)strlen(line), 0, delim, fields, fields_length, (e_svopt)(SV_TERMINATE_LF|SV_TERMINATE_CRLF));

		if( columns < mincols ) {
			ShowError("sv_readdb: Insufficient columns in line %d of \"%s\" (found %d, need at least %d).\n", lines, path, columns, mincols);
			continue; // not enough columns
		}
		if( columns > maxcols ) {
			ShowError("sv_readdb: Too many columns in line %d of \"%s\" (found %d, maximum is %d).\n", lines, path, columns, maxcols );
			continue; // too many columns
		}
		if( entries == maxrows ) {
			ShowError("sv_readdb: Reached the maximum allowed number of entries (%d) when parsing file \"%s\".\n", maxrows, path);
			break;
		}

		// parse this row
		if( !parseproc(fields+1, columns, entries) ) {
			ShowError("sv_readdb: Could not process contents of line %d of \"%s\".\n", lines, path);
			continue; // invalid row contents
		}

		// success!
		entries++;
	}

	aFree(fields);
	fclose(fp);
	ShowStatus("Done reading '"CL_WHITE"%d"CL_RESET"' entries in '"CL_WHITE"%s"CL_RESET"'.\n", entries, path);

	return true;
}

/////////////////////////////////////////////////////////////////////
// StringBuf - dynamic string
//
// @author MouseJstr (original)

/// Allocates a StringBuf
StringBuf* StringBuf_Malloc(void)  {
	StringBuf* self;
	CREATE(self, StringBuf, 1);
	StrBuf->Init(self);
	return self;
}

/// Initializes a previously allocated StringBuf
void StringBuf_Init(StringBuf* self) {
	self->max_ = 1024;
	self->ptr_ = self->buf_ = (char*)aMalloc(self->max_ + 1);
}

/// Appends the result of printf to the StringBuf
int StringBuf_Printf(StringBuf *self, const char *fmt, ...) __attribute__((format(printf, 2, 3)));
int StringBuf_Printf(StringBuf *self, const char *fmt, ...) {
	int len;
	va_list ap;

	va_start(ap, fmt);
	len = StrBuf->Vprintf(self, fmt, ap);
	va_end(ap);

	return len;
}

/// Appends the result of vprintf to the StringBuf
int StringBuf_Vprintf(StringBuf* self, const char* fmt, va_list ap) {
	for(;;) {
		va_list apcopy;
		int n, off;
		/* Try to print in the allocated space. */
		size_t size = self->max_ - (self->ptr_ - self->buf_);
		va_copy(apcopy, ap);
		n = vsnprintf(self->ptr_, size, fmt, apcopy);
		va_end(apcopy);
		/* If that worked, return the length. */
		if( n > -1 && (size_t)n < size ) {
			self->ptr_ += n;
			return (int)(self->ptr_ - self->buf_);
		}
		/* Else try again with more space. */
		self->max_ *= 2; // twice the old size
		off = (int)(self->ptr_ - self->buf_);
		self->buf_ = (char*)aRealloc(self->buf_, self->max_ + 1);
		self->ptr_ = self->buf_ + off;
	}
}

/// Appends the contents of another StringBuf to the StringBuf
int StringBuf_Append(StringBuf* self, const StringBuf* sbuf) {
	size_t available = self->max_ - (self->ptr_ - self->buf_);
	size_t needed = sbuf->ptr_ - sbuf->buf_;

	if( needed >= available ) {
		size_t off = (self->ptr_ - self->buf_);
		self->max_ += needed;
		self->buf_ = (char*)aRealloc(self->buf_, self->max_ + 1);
		self->ptr_ = self->buf_ + off;
	}

	memcpy(self->ptr_, sbuf->buf_, needed);
	self->ptr_ += needed;
	return (int)(self->ptr_ - self->buf_);
}

// Appends str to the StringBuf
int StringBuf_AppendStr(StringBuf* self, const char* str)  {
	size_t available = self->max_ - (self->ptr_ - self->buf_);
	size_t needed = strlen(str);

	if( needed >= available ) {
		// not enough space, expand the buffer (minimum expansion = 1024)
		size_t off = (self->ptr_ - self->buf_);
		self->max_ += max(needed, 1024);
		self->buf_ = (char*)aRealloc(self->buf_, self->max_ + 1);
		self->ptr_ = self->buf_ + off;
	}

	memcpy(self->ptr_, str, needed);
	self->ptr_ += needed;
	return (int)(self->ptr_ - self->buf_);
}

// Returns the length of the data in the Stringbuf
int StringBuf_Length(StringBuf* self)  {
	return (int)(self->ptr_ - self->buf_);
}

/// Returns the data in the StringBuf
char* StringBuf_Value(StringBuf* self)  {
	*self->ptr_ = '\0';
	return self->buf_;
}

/// Clears the contents of the StringBuf
void StringBuf_Clear(StringBuf* self)  {
	self->ptr_ = self->buf_;
}

/// Destroys the StringBuf
void StringBuf_Destroy(StringBuf* self) {
	aFree(self->buf_);
	self->ptr_ = self->buf_ = 0;
	self->max_ = 0;
}

// Frees a StringBuf returned by StringBuf_Malloc
void StringBuf_Free(StringBuf* self)  {
	StrBuf->Destroy(self);
	aFree(self);
}
void strlib_defaults(void) {
	/* connect */
	strlib = &strlib_s;
	StrBuf = &stringbuf_s;
	sv = &sv_s;
	/* link~u! */
	strlib->jstrescape = jstrescape;
	strlib->jstrescapecpy = jstrescapecpy;
	strlib->jmemescapecpy = jmemescapecpy;
	strlib->remove_control_chars_ = strlib_remove_control_chars;
	strlib->trim_ = strlib_trim;
	strlib->normalize_name_ = strlib_normalize_name;
	strlib->stristr_ = strlib_stristr;

#if !(defined(WIN32) && defined(_MSC_VER) && _MSC_VER >= 1400) && !defined(HAVE_STRNLEN)
	strlib->strnlen_ = strlib_strnlen;
#else
	strlib->strnlen_ = NULL;
#endif

#ifdef WIN32
	strlib->strtok_r_ = strlib_strtok_r;
#else
	strlib->strtok_r_ = NULL;
#endif

	strlib->e_mail_check_ = strlib_e_mail_check;
	strlib->config_switch_ = strlib_config_switch;
	strlib->safestrncpy_ = strlib_safestrncpy;
	strlib->safestrnlen_ = strlib_safestrnlen;
	strlib->safesnprintf_ = strlib_safesnprintf;
	strlib->strline_ = strlib_strline;
	strlib->bin2hex_ = strlib_bin2hex;

	StrBuf->Malloc = StringBuf_Malloc;
	StrBuf->Init = StringBuf_Init;
	StrBuf->Printf = StringBuf_Printf;
	StrBuf->Vprintf = StringBuf_Vprintf;
	StrBuf->Append = StringBuf_Append;
	StrBuf->AppendStr = StringBuf_AppendStr;
	StrBuf->Length = StringBuf_Length;
	StrBuf->Value = StringBuf_Value;
	StrBuf->Clear = StringBuf_Clear;
	StrBuf->Destroy = StringBuf_Destroy;
	StrBuf->Free = StringBuf_Free;

	sv->parse_next = sv_parse_next;
	sv->parse = sv_parse;
	sv->split = sv_split;
	sv->escape_c = sv_escape_c;
	sv->unescape_c = sv_unescape_c;
	sv->skip_escaped_c = skip_escaped_c;
	sv->readdb = sv_readdb;
}