如何在ubuntu中使用C語言在.dat文件中追加數據？

Question

這裏是在即時得到錯誤代碼....

for (i=0; i<portcount; i++) 
{ 
    printf("%f ", ccds[i]/100000); 
    fp=fopen("/administrator/IDS/et.dat", "a"); 
    //fprintf(fp, "er");   
    fprintf(fp, "%d ", (int)ccds[i]/100000); 
    fclose(fp); 
} 

Answer 1

您應該檢查該文件實際上是打開成功，而且很可能也把文件打開/關閉外循環：

fp = fopen("/administrator/IDS/et.dat", "a"); 
if (fp == NULL)    // always check for success when opening a file 
{ 
    perror("fopen failed"); 
} 
else 
{ 
    for (i = 0; i < portcount; i++) 
    { 
     fprintf(fp, "%d ", (int)ccds[i]/100000); 
    } 
    fclose(fp); 
}