/* $Id: utf-8-case.cpp 93115 2022-01-01 11:31:46Z vboxsync $ */ /** @file * IPRT - UTF-8 Case Sensitivity and Folding, Part 1. */ /* * Copyright (C) 2006-2022 Oracle Corporation * * This file is part of VirtualBox Open Source Edition (OSE), as * available from http://www.virtualbox.org. This file is free software; * you can redistribute it and/or modify it under the terms of the GNU * General Public License (GPL) as published by the Free Software * Foundation, in version 2 as it comes in the "COPYING" file of the * VirtualBox OSE distribution. VirtualBox OSE is distributed in the * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind. * * The contents of this file may alternatively be used under the terms * of the Common Development and Distribution License Version 1.0 * (CDDL) only, as it comes in the "COPYING.CDDL" file of the * VirtualBox OSE distribution, in which case the provisions of the * CDDL are applicable instead of those of the GPL. * * You may elect to license modified versions of this file under the * terms and conditions of either the GPL or the CDDL or both. */ /********************************************************************************************************************************* * Header Files * *********************************************************************************************************************************/ #include #include "internal/iprt.h" #include #include #include #include #include "internal/string.h" /** * Performs a case insensitive string compare between two UTF-8 strings. * * This is a simplified compare, as only the simplified lower/upper case folding * specified by the unicode specs are used. It does not consider character pairs * as they are used in some languages, just simple upper & lower case compares. * * The result is the difference between the mismatching codepoints after they * both have been lower cased. * * If the string encoding is invalid the function will assert (strict builds) * and use RTStrCmp for the remainder of the string. * * @returns < 0 if the first string less than the second string. * @returns 0 if the first string identical to the second string. * @returns > 0 if the first string greater than the second string. * @param psz1 First UTF-8 string. Null is allowed. * @param psz2 Second UTF-8 string. Null is allowed. */ RTDECL(int) RTStrICmp(const char *psz1, const char *psz2) { if (psz1 == psz2) return 0; if (!psz1) return -1; if (!psz2) return 1; const char *pszStart1 = psz1; for (;;) { /* Get the codepoints */ RTUNICP uc1; int rc = RTStrGetCpEx(&psz1, &uc1); if (RT_FAILURE(rc)) { AssertRC(rc); psz1--; break; } RTUNICP uc2; rc = RTStrGetCpEx(&psz2, &uc2); if (RT_FAILURE(rc)) { AssertRC(rc); psz2--; psz1 = RTStrPrevCp(pszStart1, psz1); break; } /* compare */ int iDiff = uc1 - uc2; if (iDiff) { iDiff = RTUniCpToUpper(uc1) != RTUniCpToUpper(uc2); if (iDiff) { iDiff = RTUniCpToLower(uc1) - RTUniCpToLower(uc2); /* lower case diff last! */ if (iDiff) return iDiff; } } /* hit the terminator? */ if (!uc1) return 0; } /* Hit some bad encoding, continue in case sensitive mode. */ return RTStrCmp(psz1, psz2); } RT_EXPORT_SYMBOL(RTStrICmp); /** * Performs a case insensitive string compare between two UTF-8 strings, given a * maximum string length. * * This is a simplified compare, as only the simplified lower/upper case folding * specified by the unicode specs are used. It does not consider character pairs * as they are used in some languages, just simple upper & lower case compares. * * The result is the difference between the mismatching codepoints after they * both have been lower cased. * * If the string encoding is invalid the function will assert (strict builds) * and use RTStrCmp for the remainder of the string. * * @returns < 0 if the first string less than the second string. * @returns 0 if the first string identical to the second string. * @returns > 0 if the first string greater than the second string. * @param psz1 First UTF-8 string. Null is allowed. * @param psz2 Second UTF-8 string. Null is allowed. * @param cchMax Maximum string length */ RTDECL(int) RTStrNICmp(const char *psz1, const char *psz2, size_t cchMax) { if (cchMax == 0) return 0; if (psz1 == psz2) return 0; if (!psz1) return -1; if (!psz2) return 1; for (;;) { /* Get the codepoints */ RTUNICP uc1; size_t cchMax2 = cchMax; int rc = RTStrGetCpNEx(&psz1, &cchMax, &uc1); if (RT_FAILURE(rc)) { AssertRC(rc); psz1--; cchMax++; break; } RTUNICP uc2; rc = RTStrGetCpNEx(&psz2, &cchMax2, &uc2); if (RT_FAILURE(rc)) { AssertRC(rc); psz2--; psz1 -= (cchMax - cchMax2 + 1); /* This can't overflow, can it? */ cchMax = cchMax2 + 1; break; } /* compare */ int iDiff = uc1 - uc2; if (iDiff) { iDiff = RTUniCpToUpper(uc1) != RTUniCpToUpper(uc2); if (iDiff) { iDiff = RTUniCpToLower(uc1) - RTUniCpToLower(uc2); /* lower case diff last! */ if (iDiff) return iDiff; } } /* hit the terminator? */ if (!uc1 || cchMax == 0) return 0; } /* Hit some bad encoding, continue in case insensitive mode. */ return RTStrNCmp(psz1, psz2, cchMax); } RT_EXPORT_SYMBOL(RTStrNICmp); RTDECL(char *) RTStrIStr(const char *pszHaystack, const char *pszNeedle) { /* Any NULL strings means NULL return. (In the RTStrCmp tradition.) */ if (!pszHaystack) return NULL; if (!pszNeedle) return NULL; /* The empty string matches everything. */ if (!*pszNeedle) return (char *)pszHaystack; /* * The search strategy is to pick out the first char of the needle, fold it, * and match it against the haystack code point by code point. When encountering * a matching code point we use RTStrNICmp for the remainder (if any) of the needle. */ const char * const pszNeedleStart = pszNeedle; RTUNICP Cp0; RTStrGetCpEx(&pszNeedle, &Cp0); /* pszNeedle is advanced one code point. */ size_t const cchNeedle = strlen(pszNeedle); size_t const cchNeedleCp0= pszNeedle - pszNeedleStart; RTUNICP const Cp0Lower = RTUniCpToLower(Cp0); RTUNICP const Cp0Upper = RTUniCpToUpper(Cp0); if ( Cp0Lower == Cp0Upper && Cp0Lower == Cp0) { /* Cp0 is not a case sensitive char. */ for (;;) { RTUNICP Cp; RTStrGetCpEx(&pszHaystack, &Cp); if (!Cp) break; if ( Cp == Cp0 && !RTStrNICmp(pszHaystack, pszNeedle, cchNeedle)) return (char *)pszHaystack - cchNeedleCp0; } } else if ( Cp0Lower == Cp0 || Cp0Upper != Cp0) { /* Cp0 is case sensitive */ for (;;) { RTUNICP Cp; RTStrGetCpEx(&pszHaystack, &Cp); if (!Cp) break; if ( ( Cp == Cp0Upper || Cp == Cp0Lower) && !RTStrNICmp(pszHaystack, pszNeedle, cchNeedle)) return (char *)pszHaystack - cchNeedleCp0; } } else { /* Cp0 is case sensitive and folds to two difference chars. (paranoia) */ for (;;) { RTUNICP Cp; RTStrGetCpEx(&pszHaystack, &Cp); if (!Cp) break; if ( ( Cp == Cp0 || Cp == Cp0Upper || Cp == Cp0Lower) && !RTStrNICmp(pszHaystack, pszNeedle, cchNeedle)) return (char *)pszHaystack - cchNeedleCp0; } } return NULL; } RT_EXPORT_SYMBOL(RTStrIStr); RTDECL(char *) RTStrToLower(char *psz) { /* * Loop the code points in the string, converting them one by one. * * ASSUMES that the folded code points have an encoding that is equal or * shorter than the original (this is presently correct). */ const char *pszSrc = psz; char *pszDst = psz; RTUNICP uc; do { int rc = RTStrGetCpEx(&pszSrc, &uc); if (RT_SUCCESS(rc)) { RTUNICP uc2 = RTUniCpToLower(uc); if (RT_LIKELY( uc2 == uc || RTUniCpCalcUtf8Len(uc2) == RTUniCpCalcUtf8Len(uc))) pszDst = RTStrPutCp(pszDst, uc2); else pszDst = RTStrPutCp(pszDst, uc); } else { /* bad encoding, just copy it quietly (uc == RTUNICP_INVALID (!= 0)). */ AssertRC(rc); *pszDst++ = pszSrc[-1]; } Assert((uintptr_t)pszDst <= (uintptr_t)pszSrc); } while (uc != 0); return psz; } RT_EXPORT_SYMBOL(RTStrToLower); RTDECL(char *) RTStrToUpper(char *psz) { /* * Loop the code points in the string, converting them one by one. * * ASSUMES that the folded code points have an encoding that is equal or * shorter than the original (this is presently correct). */ const char *pszSrc = psz; char *pszDst = psz; RTUNICP uc; do { int rc = RTStrGetCpEx(&pszSrc, &uc); if (RT_SUCCESS(rc)) { RTUNICP uc2 = RTUniCpToUpper(uc); if (RT_LIKELY( uc2 == uc || RTUniCpCalcUtf8Len(uc2) == RTUniCpCalcUtf8Len(uc))) pszDst = RTStrPutCp(pszDst, uc2); else pszDst = RTStrPutCp(pszDst, uc); } else { /* bad encoding, just copy it quietly (uc == RTUNICP_INVALID (!= 0)). */ AssertRC(rc); *pszDst++ = pszSrc[-1]; } Assert((uintptr_t)pszDst <= (uintptr_t)pszSrc); } while (uc != 0); return psz; } RT_EXPORT_SYMBOL(RTStrToUpper);