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c - 不能只释放一个动态分配的元素

问题描述

所以基本上我有一个功能，它是一个大学结构并用学生填充它。这一切都有效！当大学返回主大学时，所有值都存储在主大学内。
然后，当我尝试释放它（主要）时，它braude.students[2].name由于某种原因而出错，没有其他原因。
例外是：CtrlsValidHeapPointer(block)。
为什么它会释放所有其他动态分配的名称，而不是这个？

university getStudentInfo(FILE * file) // Definition of the getStudentInfo function
{ // This function reads student information from a file
  // and updates a university with this information using a pointer
    int i = 1, j;
    char name[99]; // A temporary name to hold the student's name.
    university tempUni; // A temporary university to hold values
    Stud * temp = (Stud*)malloc(sizeof(Stud)); // Allocating memory
                                              //  for an array of students

    if (temp == NULL) // In case there wasn't enough space 
        Error_Msg("Couldn't allocate enough memory.");

    while (getInfo(file, name, &temp[i - 1]) == 8)
    // Using getInfo==8, because in each row, there are 8 variables to scan
    {
        temp[i - 1].name = (char*)malloc(sizeof(char)*strlen(name) + 1);
        // Allocating memory for the current element's name.

        if (temp[i - 1].name == NULL) // In case there wasn't enough space, terminate
            Error_Msg("Couldn't allocate enough memory.");
        strcpy(temp[i - 1].name, name);
        // If there was, copy the name from "name" to the current student's name.

        i++; // Increase i by one to have space in memory for one more student
        temp = (Stud*)realloc(temp, i * sizeof(Stud));
        // Realloc temp, to make more space for one more student.

        if (temp == NULL) // In case there wasn't enough space, terminate.
            Error_Msg("Couldn't allocate enough memory.");
    }

    tempUni.students = (Stud*)malloc(sizeof(temp));
    // Allocating memory for students of the university, with the size of temp

    if (tempUni.students == NULL)
        // In case there wasn't enough space, terminate.
        Error_Msg("Couldn't allocate enough memory.");

    tempUni.students->marks[5] = '\0'; // Making the last mark in the string \0
    tempUni.students = temp; // Let the temporary university array of students be temp 
    tempUni.studentCount = i - 1; // How many students
    return tempUni; // Update the pointed university to have the same values as tempUni
}

但是当我在 main 中释放动态分配的内存时，就像这样： 

free(braude.students[0].name);
    free(braude.students[1].name);
            free(braude.students[2].name); // Crashes here???
            free(braude.students[3].name);
            free(braude.students);

标签： cmemoryerror-handling

解决方案

这条线

tempUni.students = (Stud*)malloc(sizeof(temp));

只为一个指针分配内存。代码不容易理解，但也许应该是

tempUni.students = malloc(i * sizeof(Stud));

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