Question

我们说我有一个名为＆＃34; ____。srt＆＃34; ，___可以是任何东西。我试图通过添加＆＃39; 1＆＃39;来改变它的名字。，所以它看起来像这样＆＃34; ____ 1.srt＆＃34;。

使用CMD，argv [1]。

从参数中读取文件

void main(int argc,char* argv[]){   
char* pt; 
pt = strstr(argv[1],".srt\0"); // checks if end of input-string is .srt
    if( pt == NULL)
    {
        fprintf(stdout,"Invalid input.\nInput file must be inputfile.srt\n");
        fprintf(stdout,"Program will now exit\n");
        return; 
    }
    strcpy(pt,'1'); 
    strcat(argv[1],".srt");

    fprintf(stdout,"%s file was created.\n",argv[1]);  }

这似乎不起作用。有人可以找出问题吗？我很感激任何帮助。谢谢

Answer 1

经过几次修改后，您的代码看起来像这样，我希望它有效。在你的代码中，你没有正确处理字符串。

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

int main(int argc,char* argv[]){
    char* pt;
    int flag;
    pt = strstr(argv[1],".srt\0"); // checks if end of input-string is .srt
    if( pt == NULL)
    {
        fprintf(stdout,"Invalid input.\nInput file must be inputfile.srt\n");
        fprintf(stdout,"Program will now exit\n");
        return 0;
    }

    pt = (char*)malloc(sizeof(argv[1] + 1)); // filename length + number or additional digits
                                             // Needed for using strncpy function
    strncpy(pt, argv[1], strlen(argv[1]) - 4); // copying filename except the .srt extention.
    strcat(pt, "1.srt"); //using pt for new filename
    flag = rename(argv[1], pt);

    if (flag == 0) // rename returns 0 on success
        fprintf(stdout,"New file name: %s\n", pt);
    else
        fprintf(stdout,"An error occurred\n");
}

使用命令提示符

1 个答案: