Aer/engine/lib/string.c

/**
 * @PROJECT     PH7 Engine for the AerScript Interpreter
 * @COPYRIGHT   See COPYING in the top level directory
 * @FILE        engine/lib/string.c
 * @DESCRIPTION String manipulation support for the PH7 Engine
 * @DEVELOPERS  Symisc Systems <devel@symisc.net>
 *              Rafal Kupiec <belliash@codingworkshop.eu.org>
 */
#include "ph7int.h"

PH7_PRIVATE sxu32 SyStrlen(const char *zSrc) {
	register const char *zIn = zSrc;
	if(zIn == 0) {
		return 0;
	}
	for(;;) {
		if(!zIn[0]) {
			break;
		}
		zIn++;
	}
	return (sxu32)(zIn - zSrc);
}
PH7_PRIVATE sxi32 SyByteFind(const char *zStr, sxu32 nLen, sxi32 c, sxu32 *pPos) {
	const char *zIn = zStr;
	const char *zEnd;
	zEnd = &zIn[nLen];
	for(;;) {
		if(zIn >= zEnd) {
			break;
		}
		if(zIn[0] == c) {
			if(pPos) {
				*pPos = (sxu32)(zIn - zStr);
			}
			return SXRET_OK;
		}
		zIn++;
	}
	return SXERR_NOTFOUND;
}
PH7_PRIVATE sxi32 SyByteFind2(const char *zStr, sxu32 nLen, sxi32 c, sxu32 *pPos) {
	const char *zIn = zStr;
	const char *zEnd;
	zEnd = &zIn[nLen - 1];
	for(;;) {
		if(zEnd < zIn) {
			break;
		}
		if(zEnd[0] == c) {
			if(pPos) {
				*pPos = (sxu32)(zEnd - zIn);
			}
			return SXRET_OK;
		}
		zEnd--;
	}
	return SXERR_NOTFOUND;
}
PH7_PRIVATE sxi32 SyByteListFind(const char *zSrc, sxu32 nLen, const char *zList, sxu32 *pFirstPos) {
	const char *zIn = zSrc;
	const char *zPtr;
	const char *zEnd;
	sxi32 c;
	zEnd = &zSrc[nLen];
	for(;;) {
		if(zIn >= zEnd) {
			break;
		}
		for(zPtr = zList ; (c = zPtr[0]) != 0 ; zPtr++) {
			if(zIn[0] == c) {
				if(pFirstPos) {
					*pFirstPos = (sxu32)(zIn - zSrc);
				}
				return SXRET_OK;
			}
		}
		zIn++;
	}
	return SXERR_NOTFOUND;
}
PH7_PRIVATE sxi32 SyStrncmp(const char *zLeft, const char *zRight, sxu32 nLen) {
	const unsigned char *zP = (const unsigned char *)zLeft;
	const unsigned char *zQ = (const unsigned char *)zRight;
	if(SX_EMPTY_STR(zP) || SX_EMPTY_STR(zQ)) {
		return SX_EMPTY_STR(zP) ? (SX_EMPTY_STR(zQ) ? 0 : -1) : 1;
	}
	if(nLen <= 0) {
		return 0;
	}
	for(;;) {
		if(nLen <= 0) {
			return 0;
		}
		if(zP[0] == 0 || zQ[0] == 0 || zP[0] != zQ[0]) {
			break;
		}
		zP++;
		zQ++;
		nLen--;
	}
	return (sxi32)(zP[0] - zQ[0]);
}
PH7_PRIVATE sxi32 SyStrnicmp(const char *zLeft, const char *zRight, sxu32 SLen) {
	register unsigned char *p = (unsigned char *)zLeft;
	register unsigned char *q = (unsigned char *)zRight;
	if(SX_EMPTY_STR(p) || SX_EMPTY_STR(q)) {
		return SX_EMPTY_STR(p) ? SX_EMPTY_STR(q) ? 0 : -1 : 1;
	}
	for(;;) {
		if(!SLen) {
			return 0;
		}
		if(!*p || !*q || SyCharToLower(*p) != SyCharToLower(*q)) {
			break;
		}
		p++;
		q++;
		--SLen;
	}
	return (sxi32)(SyCharToLower(p[0]) - SyCharToLower(q[0]));
}
sxu32 Systrcpy(char *zDest, sxu32 nDestLen, const char *zSrc, sxu32 nLen) {
	unsigned char *zBuf = (unsigned char *)zDest;
	unsigned char *zIn = (unsigned char *)zSrc;
	unsigned char *zEnd;
	if(zSrc == (const char *)zDest) {
		return 0;
	}
	if(nLen <= 0) {
		nLen = SyStrlen(zSrc);
	}
	zEnd = &zBuf[nDestLen - 1]; /* reserve a room for the null terminator */
	for(;;) {
		if(zBuf >= zEnd || nLen == 0) {
			break;
		}
		zBuf[0] = zIn[0];
		zIn++;
		zBuf++;
		nLen--;
	}
	zBuf[0] = 0;
	return (sxu32)(zBuf - (unsigned char *)zDest);
}
PH7_PRIVATE char *SyStrtok(char *str, const char *sep) {
	static int pos;
	static char *s;	
	int i = 0;
	int start = pos;
	/* Copy the string for further SyStrtok() calls */
	if(str != NULL) {
		s = str;
	}
	while(s[pos] != '\0') {
		i = 0;
		/* Compare of one of the delimiter matches the character in the string */
		while(sep[i] != '\0') {
			if(s[pos] == sep[i]) {
				/* Replace the delimter by \0 to break the string */
				s[pos] = '\0';
				pos++;
				/* Check for the case where there is no relevant string before the delimeter */
				if(s[start] != '\0') {
					return &s[start];
				} else {
					start = pos;
					pos--;
					break;
				}
			}
			i++;
		}
		pos++;
	}
	s[pos] = '\0';
	if(s[start] == '\0') {
		return NULL;
	} else {
		return &s[start];
	}
}
sxi32 SyAsciiToHex(sxi32 c) {
	if(c >= 'a' && c <= 'f') {
		c += 10 - 'a';
		return c;
	}
	if(c >= '0' && c <= '9') {
		c -= '0';
		return c;
	}
	if(c >= 'A' && c <= 'F') {
		c += 10 - 'A';
		return c;
	}
	return 0;
}