逻辑覆盖法是设计白盒测试用例主要方法之一，通过对程序逻辑结构遍历实现程序覆盖。针对以下由C语言编写程序，按要求回答问题。
阅读下列说明，回答问题。 【说明】 逻辑覆盖法是设计白盒测试用例主要方法之一，通过对程序逻辑结构遍历实现程序覆盖。针对以下由C语言编写程序，按要求回答问题。 int XOR(char * filename, unsignedlong key){ FILE * input = NULL , *output =NULL; //i char * outfilename = NULL; int len = strlen(filename); unsigned char buffer; if( (filename[len-2] == '.')&& (filename[len-1] == 'c') ) { //2,3 outfilename = new char[len+1]; //4 strcpy(outfilename, filename); outfilename[len-2] = '\0'; } else{ //5 outfilename = new char[len+5]; strcpy(outfilename, filename); strncat(outfilename,".c",2); } input =fopen(filename,"rb"); if( input == NULL) { //6 cout ＜＜ "Error opening file " ＜＜ filename ＜＜ endl; //7 delete [] outfilename; outfilename = NULL; return 1; } output =fopen(outfilename,"wb"); if( output == NULL ) { //8 cout ＜＜ "Error creating output file " ＜＜ outfilename ＜＜ endl; //9 delete [] outfilename; outfilename = NULL; return 1; } while( ! feof(input) ) { //10 if(fread(&buffer,sizeof(unsigned char),1,input) != 1 ) { //11 if( ! feof(input) ) { //12 delete [] outfilename; //13 outfilename = NULL; fclose(input); fclose(output); return 1; } } else{ //14 buffer ^= key; fwrite(&buffer,sizeof(unsigned char),1,output); } } fclose(input); //15 fclose(output); delete [] outfilename; return 0; }
请给出问题2中控制流图线性无关路径。
线性无关路径：
1．1-2-5-6-7 2．1-2-3-5-6-7 3．1-2-3-4-6-7 4．1-2-5-6-8-9 5．1-2-5-6-8-10-15 6．1-2-5-6-8-10-11-14-10... 7．1-2-5-6-8-10-11-12-10... 8．1-2-5-6-8-10-11-12-13
【解析】
本问题考查白盒测试用例设计方法：基本路径法。涉及知识点包括：根据控制流图和环路复杂度给出线性无关路径。线性无关路径是指包含一组以前没有处理语句或条件路径。从控制流图上来看，一条线性无关路径是至少包含一条在其他线性无关路径中从未有过边路径。程序环路复杂度等于线性无关路径条数，所以本题中应该有8条线性无关路径。
