c - C 中的段错误(代码转储)错误

Question

我试图运行此代码，它显示“段错误(代码已转储)”，我如何修复我的代码以使此错误消失。这是我的代码，所以如果有人可以帮助我，那就太棒了!我该如何修复无效的搜索

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

struct _data {
    char *name;
    long number;
};
int SCAN(FILE *(*stream)){
    int count = 0;
    char line[256];
    while (fgets(line, sizeof(line), *stream)) {
        count++;
    }
    return count;
}
struct _data*  BlackBoxLOAD(FILE **stream, int size){
    struct _data* BlackBox = (struct _data*)malloc(sizeof(struct _data)*size);
    int count = 0;
    char line[256];
    while (fgets(line, sizeof(line), *stream)) {
        char* token = strtok(line, " ");
        struct _data* temp = (struct _data*)malloc(sizeof(struct _data));
        temp->name = token;
        token = strtok(NULL, " ");
        temp->number = atoi(token);
        BlackBox[count] = *temp;
        count++;
    }
    return BlackBox;
}
void SEARCH(struct _data *BlackBox, char *string, int size){
    int i = 0;
    for (i = 0; i<size; i++){
        if (strcmp(BlackBox[i].name, string) == 0)
            return i;
    }
    return -1;
}
void FREE(struct _data *BlackBox, int size){
    free(BlackBox);
    return;
}
int main(int argc, char **argv) {
    int i = 0, size = 0;
    FILE *stream = fopen("hw5.data", "r");
    int noOfLines = SCAN(&stream);
    size = noOfLines;
    struct _data *BlackBox = BlackBoxLOAD(&stream, size);
    fclose(stream);
    for (i = 1; i<argc; i++){
        if (argv[i] == "") {
            printf("*******************************************");
            printf("* You must include a name to search for. *");
            printf("*******************************************");
        }
        int pos = SEARCH(BlackBox, argv[i], size);
        if (pos == -1) {
            printf("*******************************************");
            printf("The name was NOT found.");
            printf("*******************************************");
        }
        else{
            printf("*******************************************");
            printf("The name was found at the %d entry.", pos);
            printf("*******************************************");
        }
    }
    FREE(BlackBox, size);
}

Answer 1

这段代码中有太多错误，但这是最明显的:

    char* token = strtok(line, " ");
    struct _data* temp = (struct _data*)malloc(sizeof(struct _data)*1000);
    temp->name = token;

您将 temp->name 设置为 token 的值。但是 token 指向 line，它正在被修改，并且很快就会不复存在，因为您在即将消失的堆栈上创建了它。

您无法保存指向要重用的内存块的指针。