C语言 Segfault while using fopen

Question

我正在从以下代码的第二行接收segfault：

FILE *output = NULL;
output = fopen("./output2.txt", "w+");

我不认为这是某种损坏的内存错误，因为当我将W 更改为R时。它在没有segfault的情况下运行。另外，它似乎在segfaults之前就创建了文件。

编辑：事实证明MRBatch是正确的

我所有的代码供参考：

void writeFile(const char *header, int numRows, int numCols, int **grades, const char  *outFile)
{
    printf("writefile successn");
    int i, j;
    FILE *output = NULL;
    output = fopen("./output2.txt", "w+");  // ERROR HERE (I was wrong, keep reading)
    printf("testestestsetsetennn");    //based off the commenters, this code 
                                          //IS reached but is never printed
    fprintf(output, "%s", *header);  //commenters stated error is here
                                     //*header should be header
    fprintf(output, "%d %dn", numRows, numCols); //output the number or rows and columns at the second line
    //output each grades(scores) in the processed 2D array grades
    for(i = 0; i < numRows; i ++ ) {    //loop through all rows
        for( j = 0; j < numCols; j ++ ) //loop through all columns in the i row
        {   
            if( j < numCols - 1 )
                fprintf(output, "%d ", grades[i][j]);
            else
                fprintf(output, "%dn", grades[i][j]);
            //printf(""%d" ", score);
        }
        //printf("n");
    }
    fclose(output); 

}

Answer 1

错误实际上是您fopen之后的第一个fprintf。

fprintf(output, "%s", *header);  //output the same header

%s格式指定器期望char *，您通过了char值（*header），它试图将其解释为地址并引起segfault。