如何在C中将命令行写入文件

Question

I'm having issues with writing this command line to a file and it's suppose to output to the screen. To me, my code looks like it should work but I'm at a complete loss (this is my first time programming in C)

Print one line describing your program

Open the first parameter as a file for writing. If no parameter is provided, write to the stdout handle

Using a loop, save the contents of the array of string pointers passed as a parameter to the main function into the file open for writing. This is usually the variable named argv.

int main(int argc, char *argv[])
{
    FILE *fp;
    int i;
    printf("Output supplying 'multiple arguments' to this program");

    fp = fopen(argv[1], "w"); //Write to file
    if(fp==NULL)
    {
           fp = stdout;
    }

    for(i=0;i<argc;i++)
    {
           fprintf(fp, argv[i]);
    }

    printf("The number of arguments printed %d", argc);

    return 0;

Any help provided would be greatly appreciated!

Answer 1

Don't ever use dynamic format strings in C. This opens you up to an extensive set of bugs, several of them security-sensitive. Instead, pass a format string that indicates your intent, like so:

for(i=0;i<argc;i++)
{
       fprintf(fp, "%s\n", argv[i]);
}