我尝试用-g编译，然后运行gdb来查找导致分段错误的行，但错误消息让我感到困惑。

Program received signal SIGSEGV, Segmentation fault.
__GI_____strtol_l_internal (nptr=0x0, endptr=endptr@entry=0x0, base=base@entry=10, group=group@entry=0, loc=0x7ffff7fb04a0 <_nl_global_locale>)
    at ../stdlib/strtol_l.c:292
292     ../stdlib/strtol_l.c: No such file or directory.

我尝试重新安装gdb以使其再次工作，但失败了。它仍然显示相同的错误消息。我后来自己发现了这个问题，并在下面的代码中标记了它。我只是好奇为什么有时候在调试字符串函数时会发生这样的事情？例如strdup、strtok、strtol等。我是不是缺少了什么要安装的东西？我希望我能彻底解决这个问题。

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

char buff[255];
#define NUM_BUCKETS 32

typedef struct Customer {
    char* email;
    char* name;
    int shoesize;
    char* food;
    struct Customer* next;
} Customer ;

unsigned long hash(char *str) {
    unsigned long hash = 0;
    int c;

    while (*str != '\0') {
        c = *str;
        hash = ((hash << 5) + hash) + (unsigned char)c;
        str++;
    }
    return hash;
}

Customer *add_friend_to_list(char *email, char *name, int shoesize, char *food, Customer *bucket) {
    Customer* customer;

    customer = malloc(sizeof(Customer));
    customer->name = strdup(name);
    customer->food = strdup(food);
    customer->shoesize = shoesize;
    customer->email = strdup(email);
    customer->next = bucket;

    return customer;
}

void add_consumer_to_hashtable(char *name, char *food, char *email, int shoesize, Customer **buckets, size_t num_buckets) {
    size_t which_bucket = hash(name) % num_buckets;
    buckets[which_bucket] = add_friend_to_list(email, name, shoesize, food, buckets[which_bucket]);
}

int main() {
    Customer* buckets[NUM_BUCKETS] = {NULL};
    int ittime = 0;
    FILE *fp = NULL;
    fp = fopen("customers.tsv", "r");
    while (true) {
        fgets(buff, 255, fp);
        if (feof(fp)) {
            break;
        }
        ittime++;
    }
    
    fclose(fp);

    fp = NULL;
    char *email = (char *)malloc(5 * sizeof(char));
    char *name = (char *)malloc(5 * sizeof(char));
    int shoesize;
    char *food = (char *)malloc(5 * sizeof(char));
    const char s[2] = "\t";
 
    fp = fopen("customers.tsv", "r");
    for (int i = 0; i < ittime + 1; i++) {        //This line cause the Segmentation Fault
        fgets(buff, 255, fp);
        char *token;

        token = strtok(buff, s);
        email = token;
        token = strtok(NULL, s);
        name = token;
        token = strtok(NULL, s);
        shoesize = atoi(token);
        token = strtok(NULL, s);
        food = token;
        add_consumer_to_hashtable(name, food, email, shoesize, buckets, NUM_BUCKETS);
    }

    fclose(fp);

    while (true) {
        char *cmd = (char *)malloc(5 * sizeof(char));

        printf("command: ");
        scanf("%s", cmd);
        if (strcmp(cmd, "add") == 0) {
            char *email1 = (char *)malloc(5 * sizeof(char));
            char *name1 = (char *)malloc(5 * sizeof(char));
            int shoesize1;
            char *food1 = (char *)malloc(5 * sizeof(char));

            printf("email address? ");
            scanf("%s", email1);
            printf("name? ");
            scanf(" %[^\n]", name1);
            printf("shoe size? ");
            scanf("%d", &shoesize1);
            printf("favorite food? ");
            scanf("%s", food1);
            add_consumer_to_hashtable(name1, food1, email1, shoesize1, buckets, NUM_BUCKETS);
            free(name1);
            free(food1);
            free(email1);
        } else if (strcmp(cmd, "lookup") == 0) {
            char *Email = (char *)malloc(5 * sizeof(char));
            printf("email address? ");
            scanf("%s", Email);
            bool exist = false;
            for (int i = 0; i < 32; i++) {
                Customer *cus = buckets[i];
                if (buckets[i] == NULL) {
                    continue;
                }
                while ((cus != NULL)) {
                    if (cus->shoesize == EOF) {
                        break;
                    }
                    if (strcmp(cus->email, Email) == 0) {
                        printf("email: %s\n", cus->email);
                        printf("name: %s\n", cus->name);
                        printf("shoesize: %d\n", cus->shoesize);
                        printf("food: %s\n", cus->food);
                        exist = true;
                        break;
                    }
                    if (cus->next != NULL) {
                        cus = cus->next;
                    } else {
                        break;
                    }
                }
            }
            if (exist == false) {
                printf("user not found!\n");
            }
        } else if (strcmp(cmd, "delete") == 0) {
            char *Email = (char *)malloc(5 * sizeof(char));
            printf("email address? ");
            scanf("%s", Email);
            bool exist = false;
            for (int i = 0; i < 32; i++) {
                Customer *cus = buckets[i];
                if (buckets[i] == NULL) {
                    continue;
                }
                while ((cus != NULL)) {
                    if (cus->shoesize == EOF) {
                        break;
                    }
                    if (strcmp(cus->email, Email) == 0) {
                        free(cus->email);
                        free(cus->food);
                        free(cus->name);
                        free(cus);
                        cus->shoesize = EOF;
                        cus = NULL;
                        exist = true;
                        break;
                    }
                    if (cus->next != NULL) {
                        cus = cus->next;
                    } else {
                        break;
                    }
                }
            }
            if (exist == false) {
                printf("user not found!\n");
            }
        } else if (strcmp(cmd, "list") == 0) {
            for (int i = 0; i < 32; i++) {
                Customer *cus = buckets[i];
                if (buckets[i] == NULL) {
                    continue;
                }
                while ((cus != NULL) && ((cus->shoesize) != EOF)) {
                    printf("email: %s\n", cus->email);
                    printf("name: %s\n", cus->name);
                    printf("shoesize: %d\n", cus->shoesize);
                    printf("food: %s\n", cus->food);
                    if (cus->next != NULL) {
                        cus = cus->next;
                        printf("\n");
                    } else {
                        break;
                    }
                }
            }
        } else if (strcmp(cmd, "quit") == 0) {
            break;
        } else if (strcmp(cmd, "save") == 0) {
            fp = fopen("customers.tsv", "w");
            for (int i = 0; i < 32; i++) {
                Customer *cus = buckets[i];
                if (buckets[i] == NULL) {
                    continue;
                }
                while ((cus != NULL) && ((cus->shoesize) != EOF)) {
                    fprintf(fp, "%s\t%s\t%d\t%s", cus->email, cus->name, cus->shoesize, cus->food);
                    if (cus->next != NULL) {
                        cus = cus->next;
                        fprintf(fp, "\n");
                    } else {
                        break;
                    }
                }
            }
            fclose(fp);
        } else {
            printf("unknown command\n");
        }
    }
    for (int i = 0; i < 32; i++) {
        Customer *tmp;
        Customer *cus = buckets[i];
        if (cus == NULL) {
            continue;
        }
        if (cus->next != NULL) {
            tmp = cus;
            cus = cus->next;
        } else {
            break;
        }
        while ((tmp != NULL)) {
            if (tmp->shoesize != EOF) {
                free(tmp->email);
                free(tmp->food);
                free(tmp->name);
                free(tmp);
            }
            cus->shoesize = EOF;
            cus = NULL;
        }
        if (tmp != NULL) {
            free(tmp);
        }
        if (cus != NULL) {
            free(cus);
        }
    }

    return 0;
}