The following function is an efficient way of converting strings from one character set to another. Using an array of 256 characters as a conversion table, the attached function replaces any invalid file name characters in lpszString with an underscore character. Of course, the conversion table can be modified to convert between any type of single-byte character sets. The function does not return any value. Nor does it require any input string buffer, since the character conversion is done in place.

 void ConvertString (char *lpszString) {   // Replaces invalid file name characters with an underscore    unsigned int uLen = strlen (lpszString) ;    // Declare static array and initialize it with your own character conversion table    static char CharacterMapping[256] =     {               // 0x00 0x01 0x02 0x03 0x04 0x05 0x06 0x07 0x08 0x09 0x0A 0x0B 0x0C 0x0D 0x0E 0x0F    /*0x00*/ '_', '_', '_', '_', '_', '_', '_', '_', '_', '_', '_', '_', '_', '_', '_', '_',    /*0x10*/ '_', '_', '_', '_', '_', '_', '_', '_', '_', '_', '_', '_', '_', '_', '_', '_',    /*0x20*/ ' ', '!', '_', '#', '$', '%', '&', ''','(', ')', '_', '+', ',', '-', '.', '_',    /*0x30*/ '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '_', ';', '_', '=', '_', '_',    /*0x40*/ '@', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O',    /*0x50*/ 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', '[', '_', ']', '^', '_',    /*0x60*/ '