C语言 命令行传参进行 异或 加密/解密

【说明】

    对指定文件中的内容或传入的文本参数进行异或加密/解密，并将加密/解密后的结果保存到文档。可以指定进行异或加密/解密时要使用的私钥。

【命令行示例】

    [root@localhost]$ ./magicTransfer xCode 64x

    这条命令的含义是如果当前目录下存在 64.txt 这个文本，则对该文本进行解密并将解密结果保存到 64x.txt 文本中；如果不存在 64.txt 文件，则从 a.txt 文件中读取要加密的内容进行加密，并将加密结果保存到 64.txt 文件中。

【源码】

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

char *pTextOrigin = NULL;

unsigned char magicTransfer(char *_src, const char _ops, FILE *_dest)
{
    unsigned char ret = 0;
    while(*_src != '\0'){
        ret += fprintf(_dest, "%c", ((*_src) ^ _ops));
        //printf("%c---%c\n", *_src, ((*_src) ^ _ops));
        ++_src;
    }
    return ret;
}

unsigned long readNcount(FILE *_src)
{
    char cReadFile;
    unsigned long ulCountWord = 0;    
    while(EOF != fscanf(_src, "%c", &cReadFile)){
        //printf("%c", cReadFile);
        ++ulCountWord;
    }
    //printf("\nulCountWord is: %d\nsizeof(char) is: %d\n", ulCountWord, sizeof(char));
    pTextOrigin = (char *)malloc((size_t)ulCountWord);
    //printf("pTextOrigin is: %x\n", pTextOrigin);  
    return ulCountWord;
}

void work(FILE *_pfSrcFile, char *_pstrDestFileName, char _ops)
{
    unsigned long nmemb = 0;
    FILE *pf = NULL;
    nmemb = readNcount(_pfSrcFile);
    //printf("pFile position is: %ld\n", ftell(pFile));
    fseek(_pfSrcFile, 0, SEEK_SET);
    //printf("pFile position is: %ld\n", ftell(pFile));
    //printf("pTextOrigin is: %x\n", pTextOrigin); 
    printf("Bytes read: %d\n", fread(pTextOrigin, sizeof(char), (size_t)nmemb, _pfSrcFile));
    //printf("File context is: %s\n", pTextOrigin);
    if (NULL != (pf = fopen(_pstrDestFileName, "wb+"))){     // 进行转换并保存到文件xxx.txt 中
        printf("character been transfered: %d\n", magicTransfer(pTextOrigin, _ops, pf));
    }
    free(pTextOrigin);
    fclose(pf);
}

int main(char argc, char **argv)
{
    //printf("Num of args: %d\n", argc);
    //printf("argv[0] is: %s\n", argv[0]);
    char cOperator = 0;
    char *cEnd; 
    FILE *pFile = NULL;
    FILE *pFileDest = NULL;
    unsigned long nmemb = 0;
    char strFilename[10] = "";

    if(argc == 3){
        if(!strcmp(argv[1], "xCode")){      // 必须以xCode参数开始
            if(argv[2]){
                cOperator = strtol(argv[2], &cEnd, 10);
                //printf("NUM is: %d\ncEnd is: %c\n", cOperator, *cEnd);
                sprintf(strFilename, "%d.txt", cOperator);
                if(*cEnd == 'x'){               // 操作数必须以x字符结尾                    
                    if(NULL == (pFileDest = fopen(strFilename, "rb"))){    // 文件xxx.txt 不存在
                        printf("Open file %s error! Searching for a.txt ...\n", strFilename);
                        if(NULL == (pFile = fopen("a.txt", "rb"))){        // 则打开文件a.txt
                            printf("Open file a.txt error!\n");
                        }else{
                            work(pFile, strFilename, cOperator);
                            fclose(pFile);
                        }
                    }else{      // 文件xxx.txt 存在
                        work(pFileDest, strcat(argv[2], ".txt"), cOperator);
                        fclose(pFileDest);
                    }
                }else{
                    printf("Hello, Magic !\n"); 
                }
            }else{
                printf("Hello, Magic !\n");
            }
        }else{
            printf("Hello, Magic !\n");
        }
    }else{
        printf("Hello, Magic !\n");
    }
    return 0;
}