Question

我需要创建一个将文件编码为base64的函数，并返回读取的字符数。所以问题是当我遇到像ÿ这样的特殊字符时，我的当前代码会遇到问题，那么解决它的最简单方法是什么？

static void encodeblock( unsigned char *in, unsigned char *out, int len )
{
    out[0] = encoding[ (int)(in[0] >> 2) ];
    out[1] = encoding[ (int)(((in[0] & 0x03) << 4) | ((in[1] & 0xf0) >> 4)) ];
    out[2] = (len > 1 ? encoding[ (int)(((in[1] & 0x0f) << 2) | ((in[2] & 0xc0) >> 6)) ] : '=');
    out[3] = (len > 2 ? encoding[ (int)(in[2] & 0x3f) ] : '=');
}

int to_base64(const char *dst_file, const char *src_file)
{
    unsigned char in[3];
        unsigned char out[4];
    int i, len, blocksout = 0;
    int count = 0;

    FILE *infile;
    infile = fopen(src_file,"r");
    if(infile==NULL){
        return -1;
    }
    FILE *outfile;
    outfile = fopen(dst_file,"w");
    if(outfile==NULL){
        return -1;
    }

        *in =  0;
        *out = 0;
    while( feof( infile ) == 0 ) {
        len = 0;
        for( i = 0; i < 3; i++ ) {
            in[i] = fgetc(infile);


            if(feof(infile) == 0 ) {
                len++;
                count+=1;
            }
            else {
                in[i] = 0;
            }
        }
        if( len > 0 ) {
            encodeblock( in, out, len );
            for( i = 0; i < 4; i++ ) {
                putc( out[i], outfile );


            }
            blocksout++;
        }
        if( blocksout >= (64/4) || feof( infile ) != 0 ) {
            if( blocksout > 0 ) {
                fprintf( outfile, "\n" );
            }
            blocksout = 0;
        }
    }
        fclose(infile);
        fclose(outfile);
    return( count );
}

Answer 1

以二进制格式打开文件并访问

C编程base64编码特殊字符

1 个答案: