我正在学习 IT,编程对我来说是新事物。上周我有一个任务要做。我必须编写一个程序,可以将结构(公司员工的个人数据)保存到 file.txt。程序应该能够找到一个特定的人(输入他的名字或姓氏)并删除所有具有用户给定姓氏的人。这些所有任务都应该在不同的功能中。到目前为止我写了这个函数:
void struktura()
{
struct Person
{
char name[30];
char surname[30];
int age;
int height;
int weight;
};
int ile;
int i = 0;
printf("\n");
printf("How many persons would you like add to database (max 10 at once): ");
scanf("%d", &ile);
printf("\n");
if (ile >= 0)
{
printf("You added no one.\n");
}
else
{
struct Person *osoba[10]; //
while (i < ile)
{
osoba[i] = (struct Person*) malloc(sizeof (struct Person));
printf("Give a name: ");
scanf("%s", osoba[i]->name);
printf("Give a surname: ");
scanf("%s", osoba[i]->surname);
printf("Age: ");
scanf("%d", &osoba[i]->age);
printf("Height: ");
scanf("%d", &osoba[i]->height);
printf("Weight: ");
scanf("%d", &osoba[i]->weight);
printf("\n");
i = i + 1;
}
printf("You have added: \n\n");
i = 0;
while (i < ile)
{
printf("%d) Name: %s, Surname: %s, Age: %d years, Height: %d cm, Weight: %d kg.\n", i + 1, osoba[i]->name, osoba[i]->surname, osoba[i]->age, osoba[i]->height, osoba[i]->weight);
i = i + 1;
}
for (i = 0; i < ile; i++)
{
free(osoba[i]);
}
}
}
此外,我有一个代码可以将这些人保存到file.txt。我想将代码(下面)分离到另一个函数,但我不知道如何将结构传递给函数。
FILE *save;
char name[30];
printf("\nWhere to save a database: ");
scanf("%s", name);
save = fopen(name, "a");
if (save == NULL)
{
printf("This file doesn't exist!");
getchar();
exit(1);
}
i = 0;
while (i < ile)
{
fprintf(save, "Name: %s, Surname: %s, Age: %d years, Height: %d cm, Weight: %d kg.\n",osoba[i]->name, osoba[i]->surname, osoba[i]->age, osoba[i]->height, osoba[i]->weight);
i = i + 1;
}
fclose(save);
我写了一个函数,它也打开了 file.txt 的全部内容。我缺少的是:如何找到一个特定的人以及如何删除这些人(我正在考虑打开第二个临时文件并复制原始文件的内容,除了这些包含给定姓名/姓氏的行)(全部在单独的功能中) .你知道我该怎么做吗?我在一些书中寻找它,但找不到任何帮助。
最佳答案
I would like to separate code (below) to another function but I don't know how to pass a structure to function.
在函数之外和之上定义struct Person
,这样它就可以在所有函数中使用。然后你可以把将人员保存到文件的代码放在一个函数中
void save(int ile, struct Person *osoba[ile])
{
…
}
并调用它
save(ile, osoba);
how to find a specific person
您可以使用以下函数,它比查找任务所需的函数稍微复杂一点,但可以重复用于其他目的:
char prformat[] =
"Name: %s, Surname: %s, Age: %d years, Height: %d cm, Weight: %d kg.\n";
char scformat[] =
"Name: %[^,], Surname: %[^,], Age:%d years, Height:%d cm, Weight:%d kg.\n";
// Read the data file "file.txt", look for 'name' or 'surname' (unless NULL),
// and output line(s) to 'out' if or unless they match (depending on 'match')
scan(char *name, char *surname, _Bool match, FILE *out)
{
FILE *fp = fopen("file.txt", "r");
if (!fp) perror("file.txt"), exit(1);
struct Person osoba;
while (fscanf(fp, scformat, osoba.name, osoba.surname,
&osoba.age, &osoba.height, &osoba.weight) == 5
)
if ( name && strcmp(osoba. name, name) == 0 == match
|| surname && strcmp(osoba.surname, surname) == 0 == match
)
if (fprintf(out, prformat, osoba.name, osoba.surname,
osoba.age, osoba.height, osoba.weight)
< 0) perror(""), exit(1);
fclose(fp);
}
调用它
char name[30];
printf("Give a name or surname to find: ");
if (scanf("%29s", name) == 1)
scan(name, name, 1, stdout); // print matching lines to stdout
delete all people whose got a surname given by user … (I was thinking about opening a second temporary file and copy an content of original file except these lines …
你想对了:
printf("Give a surname to delete: ");
if (scanf("%29s", name) == 1)
{
FILE *fp = fopen("file.tmp", "w");
if (!fp) perror("file.tmp"), exit(1);
scan(NULL, name, 0, fp); // print non-matching lines to tempfile
if (fclose(fp) < 0) perror("file.tmp"), exit(1);
remove("file.txt");
if (rename("file.tmp", "file.txt") != 0) perror("file.tmp");
}
关于c - 从 txt 文件中保存、查找和删除结构,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/30164542/