二进制文件每两个的字节位置交换

（一）.写作缘由：

写这篇博客的目的是是为了方便下次使用或者帮助其他需要的人。在打CTF的时候，偶尔会遇到还原一些文件，笔者遇到的是分析数据流量的时候，提取出了一个未知文件，用二进制编辑器打开，搜所文件头，发现和某个文件头有点相似，但是每两个字节位置颠倒了，于是就想到把每两个字节交换位置，就像下面这种:

（二）.演示及效果:

在命令行执行前后如下图:

（三）.贴上代码:

代码是C写的，有点多不太美观，功能太单一， 也没弄啥模块化，编写环境是windows。

#include #include #include int main(int argc, const char** argv){        //The pointer of input file and output file        FILE *fin;        FILE* fout;                //The file name of input file and output        char* inFile;        char* outFile;        //The pointer of single and double byte type        unsigned short* pDouble = NULL;        unsigned char* pSingle = NULL;        //The memery buffer of header and tail pointer about input file        void* fBuffStart = NULL;        void* fBuffEnd = NULL;        //The size of input file (Byte)        unsigned long fileSize = 0;        //Judge the count of parameter and the file name limit         if(argc != 3 || strlen(argv[1]) > 255 || strlen(argv[2]) > 255)        {                printf("\n[-]Usage: %s infile outfile\n", argv[0]);                printf("[-]Filename limited: 255 Byte\n");                exit(-1);        }        inFile = argv[1];        outFile = argv[2];        //Exception handling        if(!(fin = fopen(inFile, "rb")))        {                printf("Error: open %s failed!\n", inFile);                exit(-1);        }        //Obtain file size        fseek(fin, 0, SEEK_END);        fileSize = ftell(fin);        fseek(fin, 0, SEEK_SET);        //Alloc memery  for input file and read its data to memery        fBuffStart = (unsigned char*)malloc(fileSize);        memset(fBuffStart, 0, fileSize);        fread(fBuffStart, 1, fileSize, fin);        fclose(fin);        //The position of start and end input file memery         fBuffEnd = (unsigned char*)fBuffStart + fileSize;        pDouble = (unsigned short*)fBuffStart;        //Exception handling        if(!(fout = fopen(outFile,"wb")))        {                printf("Error: open %s failed!\n", outFile);                exit(-1);        }        //Exchange position of each two byte        while(pDouble != fBuffEnd)        {                pSingle = pDouble;                fwrite(pSingle+1, 1, 1, fout);                fwrite(pSingle, 1, 1, fout);                pDouble++;        }        fclose(fout);        return 0;}

（四）.若有不足之处，还请斧正。