C源文件的位置预定义在 __FILE__宏里面，比如

#include <stdio.h>
int main()
{
   // Prints location of C this C code.
   printf("%s",__FILE__);
}

以上打印的输出就是C源程序的位置
下面的程序显示了如何打印源程序自身

// A C program that prints its source code.
#include <stdio.h>
  
int main(void)
{
    // We can append this code to any C program
    // such that it prints its source code.

    char c;

    FILE*fp = fopen(__FILE__,"r");
  
    do
    {
        c = fgetc(fp);
        putchar(c);
    }
    while(c != EOF);
  
    fclose(fp);
  
    return 0;
}


Output :

// A C program that prints its source code.
#include <stdio.h>
 
int main(void)
{
    // We can append this code to any C program
    // such that it prints its source code.

    char c;

    FILE*fp = fopen(__FILE__,"r");
  
    do
    {
        c = fgetc(fp);
        putchar(c);
    }
    while(c != EOF);
  
    fclose(fp);
  
    return 0;
}