cpl_string.cpp

mitab,读取MapInfo的地图文件

 *
 * @param pszValue the string should be tested.
 * 
 * @return TRUE or FALSE.
 */

int CSLTestBoolean( const char *pszValue )
{
    if( EQUAL(pszValue,"NO")
        || EQUAL(pszValue,"FALSE") 
        || EQUAL(pszValue,"OFF") 
        || EQUAL(pszValue,"0") )
        return FALSE;
    else
        return TRUE;
}

/**********************************************************************
 *                       CSLFetchBoolean()
 *
 * Check for boolean key value.
 *
 * In a StringList of "Name=Value" pairs, look to see if there is a key
 * with the given name, and if it can be interpreted as being TRUE.  If
 * the key appears without any "=Value" portion it will be considered true. 
 * If the value is NO, FALSE or 0 it will be considered FALSE otherwise
 * if the key appears in the list it will be considered TRUE.  If the key
 * doesn't appear at all, the indicated default value will be returned. 
 * 
 * @param papszStrList the string list to search.
 * @param pszKey the key value to look for (case insensitive).
 * @param bDefault the value to return if the key isn't found at all. 
 * 
 * @return TRUE or FALSE 
 **********************************************************************/

int CSLFetchBoolean( char **papszStrList, const char *pszKey, int bDefault )

{
    const char *pszValue;

    if( CSLFindString( papszStrList, pszKey ) != -1 )
        return TRUE;

    pszValue = CSLFetchNameValue(papszStrList, pszKey );
    if( pszValue == NULL )
        return bDefault;
    else 
        return CSLTestBoolean( pszValue );
}

/**********************************************************************
 *                       CSLFetchNameValue()
 *
 * In a StringList of "Name=Value" pairs, look for the
 * first value associated with the specified name.  The search is not
 * case sensitive.
 * ("Name:Value" pairs are also supported for backward compatibility
 * with older stuff.)
 * 
 * Returns a reference to the value in the StringList that the caller
 * should not attempt to free.
 *
 * Returns NULL if the name is not found.
 **********************************************************************/
const char *CSLFetchNameValue(char **papszStrList, const char *pszName)
{
    size_t nLen;

    if (papszStrList == NULL || pszName == NULL)
        return NULL;

    nLen = strlen(pszName);
    while(*papszStrList != NULL)
    {
        if (EQUALN(*papszStrList, pszName, nLen)
            && ( (*papszStrList)[nLen] == '=' || 
                 (*papszStrList)[nLen] == ':' ) )
        {
            return (*papszStrList)+nLen+1;
        }
        papszStrList++;
    }
    return NULL;
}

/**********************************************************************
 *                       CPLParseNameValue()
 **********************************************************************/

/**
 * Parse NAME=VALUE string into name and value components.
 *
 * Note that if ppszKey is non-NULL, the key (or name) portion will be
 * allocated using VSIMalloc(), and returned in that pointer.  It is the
 * applications responsibility to free this string, but the application should
 * not modify or free the returned value portion. 
 *
 * This function also support "NAME:VALUE" strings and will strip white
 * space from around the delimeter when forming name and value strings.
 *
 * Eventually CSLFetchNameValue() and friends may be modified to use 
 * CPLParseNameValue(). 
 * 
 * @param pszNameValue string in "NAME=VALUE" format. 
 * @param ppszKey optional pointer though which to return the name
 * portion. 
 * @return the value portion (pointing into original string). 
 */

const char *CPLParseNameValue(const char *pszNameValue, char **ppszKey )

{
    int  i;
    const char *pszValue;

    for( i = 0; pszNameValue[i] != '\0'; i++ )
    {
        if( pszNameValue[i] == '=' || pszNameValue[i] == ':' )
        {
            pszValue = pszNameValue + i + 1;
            while( *pszValue == ' ' || *pszValue == '\t' )
                pszValue++;

            if( ppszKey != NULL )
            {
                *ppszKey = (char *) CPLMalloc(i+1);
                strncpy( *ppszKey, pszNameValue, i );
                (*ppszKey)[i] = '\0';
                while( i > 0 && 
                       ( (*ppszKey)[i] == ' ' || (*ppszKey)[i] == '\t') )
                {
                    (*ppszKey)[i] = '\0';
                    i--;
                }
            }

            return pszValue;
        }
    }

    return NULL;
}

/**********************************************************************
 *                       CSLFetchNameValueMultiple()
 *
 * In a StringList of "Name=Value" pairs, look for all the
 * values with the specified name.  The search is not case
 * sensitive.
 * ("Name:Value" pairs are also supported for backward compatibility
 * with older stuff.)
 * 
 * Returns stringlist with one entry for each occurence of the
 * specified name.  The stringlist should eventually be destroyed
 * by calling CSLDestroy().
 *
 * Returns NULL if the name is not found.
 **********************************************************************/
char **CSLFetchNameValueMultiple(char **papszStrList, const char *pszName)
{
    size_t nLen;
    char **papszValues = NULL;

    if (papszStrList == NULL || pszName == NULL)
        return NULL;

    nLen = strlen(pszName);
    while(*papszStrList != NULL)
    {
        if (EQUALN(*papszStrList, pszName, nLen)
            && ( (*papszStrList)[nLen] == '=' || 
                 (*papszStrList)[nLen] == ':' ) )
        {
            papszValues = CSLAddString(papszValues, 
                                          (*papszStrList)+nLen+1);
        }
        papszStrList++;
    }

    return papszValues;
}


/**********************************************************************
 *                       CSLAddNameValue()
 *
 * Add a new entry to a StringList of "Name=Value" pairs,
 * ("Name:Value" pairs are also supported for backward compatibility
 * with older stuff.)
 * 
 * This function does not check if a "Name=Value" pair already exists
 * for that name and can generate multiple entryes for the same name.
 * Use CSLSetNameValue() if you want each name to have only one value.
 *
 * Returns the modified stringlist.
 **********************************************************************/
char **CSLAddNameValue(char **papszStrList, 
                    const char *pszName, const char *pszValue)
{
    char *pszLine;

    if (pszName == NULL || pszValue==NULL)
        return papszStrList;

    pszLine = (char *) CPLMalloc(strlen(pszName)+strlen(pszValue)+2);
    sprintf( pszLine, "%s=%s", pszName, pszValue );
    papszStrList = CSLAddString(papszStrList, pszLine);
    CPLFree( pszLine );

    return papszStrList;
}

/************************************************************************/
/*                          CSLSetNameValue()                           */
/************************************************************************/

/**
 * Assign value to name in StringList.
 *
 * Set the value for a given name in a StringList of "Name=Value" pairs
 * ("Name:Value" pairs are also supported for backward compatibility
 * with older stuff.)
 * 
 * If there is already a value for that name in the list then the value
 * is changed, otherwise a new "Name=Value" pair is added.
 *
 * @param papszList the original list, the modified version is returned.
 * @param pszName the name to be assigned a value.  This should be a well
 * formed token (no spaces or very special characters). 
 * @param pszValue the value to assign to the name.  This should not contain
 * any newlines (CR or LF) but is otherwise pretty much unconstrained.  If
 * NULL any corresponding value will be removed.
 *
 * @return modified stringlist.
 */

char **CSLSetNameValue(char **papszList, 
                       const char *pszName, const char *pszValue)
{
    char **papszPtr;
    size_t nLen;

    if (pszName == NULL )
        return papszList;

    nLen = strlen(pszName);
    papszPtr = papszList;
    while(papszPtr && *papszPtr != NULL)
    {
        if (EQUALN(*papszPtr, pszName, nLen)
            && ( (*papszPtr)[nLen] == '=' || 
                 (*papszPtr)[nLen] == ':' ) )
        {
            /* Found it!  
             * Change the value... make sure to keep the ':' or '='
             */
            char cSep;
            cSep = (*papszPtr)[nLen];

            CPLFree(*papszPtr);

            /* 
             * If the value is NULL, remove this entry completely/
             */
            if( pszValue == NULL )
            {
                while( papszPtr[1] != NULL )
                {
                    *papszPtr = papszPtr[1];
                    papszPtr++;
                }
                *papszPtr = NULL;
            }

            /*
             * Otherwise replace with new value.
             */
            else
            {
                *papszPtr = (char *) CPLMalloc(strlen(pszName)+strlen(pszValue)+2);
                sprintf( *papszPtr, "%s%c%s", pszName, cSep, pszValue );
            }
            return papszList;
        }
        papszPtr++;
    }

    if( pszValue == NULL )
        return papszList;

    /* The name does not exist yet... create a new entry
     */
    return CSLAddNameValue(papszList, pszName, pszValue);
}

/************************************************************************/
/*                      CSLSetNameValueSeparator()                      */
/************************************************************************/

/**
 * Replace the default separator (":" or "=") with the passed separator
 * in the given name/value list. 
 *
 * Note that if a separator other than ":" or "=" is used, the resulting
 * list will not be manipulatable by the CSL name/value functions any more.
 *
 * The CPLParseNameValue() function is used to break the existing lines, 
 * and it also strips white space from around the existing delimiter, thus
 * the old separator, and any white space will be replaced by the new
 * separator.  For formatting purposes it may be desireable to include some
 * white space in the new separator.  eg. ": " or " = ".
 * 
 * @param papszList the list to update.  Component strings may be freed
 * but the list array will remain at the same location.
 *
 * @param pszSeparator the new separator string to insert.  
 *
 */

void CSLSetNameValueSeparator( char ** papszList, const char *pszSeparator )

{
    int         nLines = CSLCount(papszList), iLine;

    for( iLine = 0; iLine < nLines; iLine++ )
    {
        char        *pszKey = NULL;
        const char  *pszValue;
        char        *pszNewLine;

        pszValue = CPLParseNameValue( papszList[iLine], &pszKey );
        if( pszValue == NULL || pszKey == NULL )
            continue;
        
        pszNewLine = (char *) CPLMalloc( strlen(pszValue) + strlen(pszKey)
                                         + strlen(pszSeparator) + 1 );
        strcpy( pszNewLine, pszKey );
        strcat( pszNewLine, pszSeparator );
        strcat( pszNewLine, pszValue );
        CPLFree( papszList[iLine] );
        papszList[iLine] = pszNewLine;
        CPLFree( pszKey );
    }
}

/************************************************************************/
/*                          CPLEscapeString()                           */
/************************************************************************/

/**
 * Apply escaping to string to preserve special characters.
 *
 * This function will "escape" a variety of special characters
 * to make the string suitable to embed within a string constant
 * or to write within a text stream but in a form that can be
 * reconstitued to it's original form.  The escaping will even preserve
 * zero bytes allowing preservation of raw binary data.
 *
 * CPLES_BackslashQuotable(0): This scheme turns a binary string into 
 * a form suitable to be placed within double quotes as a string constant.
 * The backslash, quote, '\0' and newline characters are all escaped in 
 * the usual C style. 
 *
 * CPLES_XML(1): This scheme converts the '<', '<' and '&' characters into
 * their XML/HTML equivelent (&gt;, &lt; and &amp;) making a string safe
 * to embed as CDATA within an XML element.  The '\0' is not escaped and 
 * should not be included in the input.
 *
 * CPLES_URL(2): Everything except alphanumerics and the underscore are 
 * converted to a percent followed by a two digit hex encoding of the character
 * (leading zero supplied if needed).  This is the mechanism used for encoding
 * values to be passed in URLs.
 *
 * CPLES_SQL(3): All single quotes are replaced with two single quotes.  
 * Suitable for use when constructing literal values for SQL commands where
 * the literal will be enclosed in single quotes.
 *
 * CPLES_CSV(4): If the values contains commas, double quotes, or newlines it 
 * placed in double quotes, and double quotes in the value are doubled.
 * Suitable for use when constructing field values for .csv files.  Note that
 * CPLUnescapeString() currently does not support this format, only 
 * CPLEscapeString().  See cpl_csv.cpp for csv parsing support.
 *
 * @param pszInput the string to escape.  
 * @param nLength The number of bytes of data to preserve.  If this is -1
 * the strlen(pszString) function will be used to compute the length.
 * @param nScheme the encoding scheme to use.  
 *
 * @return an escaped, zero terminated string that should be freed with 
 * CPLFree() when no longer needed.
 */

char *CPLEscapeString( const char *pszInput, int nLength, 
                       int nScheme )

{
    char        *pszOutput;
    char        *pszShortOutput;

    if( nLength == -1 )