无法读取写在 C 文件上的行

Question

我一直在开发这个项目，其中每个进程在被 fork 后都会将其信息写入一个文件，供父级读取。我还为家长编写了一个小片段来阅读这个文件，但每次我运行这段代码时它都不起作用。相反，当我以下列格式手动写入文件时:

• 567 |一个 |乙 | 20
• 568 |否 |一个 | 2
• 569 | Z |乙 | 12

我可以正常阅读，但是当我运行这段代码时:

  #include "header.h"


  struct Individui {
       pid_t pid;
       char tipo[50];
       char nome[50];
       unsigned long genoma;
  };


int main(int argc, char *argv[]) {

    Individuo individuo;
    srand(getpid());

    int min = 2;
    int max = atoi(argv[2]);
    int diff = max - min;
    int r;
    r = rand() % (diff + 1) + min;

    char randomletter = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"[rand() % 26];

    individuo.pid = getpid();
    strcpy( individuo.tipo, argv[0]);
    strcpy( individuo.nome, &randomletter);
    individuo.genoma = r;

    FILE *f = fopen("dati.txt", "a");
    if (f == NULL)
    {
        printf("Error opening file!\n");
        exit(1);
    }

    fprintf(f, "%d | %s | %s | %lu\r", individuo.pid, individuo.nome, individuo.tipo, individuo.genoma);

    fclose(f);

    return 0;
}

然后用这段代码读取文件，它不起作用:

int main(){
    char name[4], type[4];
    int pids[4];
    unsigned long genome[4];
    int i = 0;

    FILE * file = fopen("dati.txt", "r"); // "r" = read
    while(fscanf(file, "%d | %c | %c | %ld\n", &pids[i], &name[i], &type[i], &genome[i]) != EOF){
        i++;
    }

    printf ("%d %c %c %lu\n", pids[0], name[0], type[0], genome[0]);
    printf ("%d %c %c %lu\n", pids[1], name[1], type[1], genome[1]);
    printf ("%d %c %c %lu\n", pids[2], name[2], type[2], genome[2]);
}

据我了解，我写的流程代码行很长，读取文件的代码不支持。我是 C 的新手，所以我真的不知道我错在哪里，我希望有人能提供帮助。

Answer 1

错误修复作者:

char randomletter[2];
randomletter[0] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"[rand() % 26];
randomletter[1] = '\0';

strcpy( individuo.nome, randomletter);

fprintf(f, "%d | %s | %s | %lu\n",
    individuo.pid, individuo.nome, individuo.tipo, individuo.genoma);

错误修正读者:

void read() {
    char name[4][50], type[4][50];
    int pids[4];
    unsigned long genome[4];

    FILE * file = fopen("dati.txt", "r"); // "r" = read
    for (int i = 0; i < 4; i++) {
        if (fscanf(file, "%d | %s | %s | %lu", &pids[i], name[i], type[i], &genome[i]) != 4)
            break;

        printf ("%d %s %s %lu\n", pids[i], name[i], type[i], genome[i]);
    }
}