在 Linux 上运行时，C fgets 函数不起作用

Question

所以我遇到的问题是我相信 fgets 被跳过，但我不确定。我正在使用的代码如下所示:

void createAccount()
{
ignore = fseek(stdin,0,SEEK_END);
printf("Creating A New Account:\n");
FILE *input;
input = fopen("accounts.txt", "a");
if (input == NULL)
{
    printf("Error opening accounts.txt file!\n");
    exit(1);
}
char username[USERNAME_LENGTH];
char password[PASSWORD_LENGTH];
char type[CHOICE_LENGTH];
char age[10];
printf("Username:");
a = fgets(username,USERNAME_LENGTH,stdin);
char *fileOpener = malloc(strlen(username));
if (fileOpener!=NULL) {
    strcpy(fileOpener, username);
}
const size_t end = strlen(fileOpener) - 1;
if (fileOpener[end] == '\n')
    fileOpener[end] = '\0';
ignore = fseek(stdin,0,SEEK_END);
printf("age:");
a = fgets(age,10,stdin);
ignore = fseek(stdin,0,SEEK_END);
printf("Password:");
a = fgets(password,PASSWORD_LENGTH,stdin);
ignore = fseek(stdin,0,SEEK_END);
printf("Account Type:");
a = fgets(type,CHOICE_LENGTH,stdin);
ignore = fseek(stdin,0,SEEK_END);
ignore = fputs(username,input);
ignore = fputs(password,input);
ignore = fputs(type,input);
fclose(input);
FILE *newFile = fopen(fileOpener,"ab+");
char *newAge = malloc(strlen("AGE: " + strlen(age)));
if (newAge!=NULL) {
    strcpy(newAge,"AGE: ");
    strcat(newAge,age);
}
char *newName =malloc(strlen("NAME: " + strlen(username)));
if (newName!=NULL) {
    strcpy(newName,"NAME: ");
    strcat(newName,username);
}
ignore = fputs(newName,newFile);
ignore = fputs(newAge,newFile);
ignore = fputs("MEDICATIONS: ",newFile);
ignore = fputs("\nVITALS: ",newFile);
ignore = fputs("\nHISTORY: ",newFile);
ignore = fputs("\nALLERGIES: ",newFile);
fclose(newFile);
printf("Account made.");
}

它扫描用户输入并将其放入文件中。问题是它从不提示输入用户名，而是直接提示年龄，输出如下所示:

Creating A New Account:
Username:age:(user input)
Password: (user input)
Account Type: (user input)

当它看起来像这样时:

Creating A New Account:
Username:(user input)
age:(user input)
Password:(user input)
Account Type:(user input)

所以看起来用户名的 fgets 被忽略了？它直接进入老化状态，将其打印在同一行上。当我在 mac 上运行这段代码时，它工作正常，但我只在 linux 上遇到这个问题。请帮忙。

Answer 1

void createAccount()
{
fseek(stdin,0,SEEK_END);
printf("Creating A New Account:\n");
FILE *input = fopen("accounts.txt", "a");
if (input == NULL)
{
    printf("Error opening accounts.txt file!\n");
    exit(1);
}
char username[USERNAME_LENGTH];
char password[PASSWORD_LENGTH];
char type[CHOICE_LENGTH];
char age[10];
printf("Username:");
fgets(username,USERNAME_LENGTH,stdin);
char *fileOpener = malloc(strlen(username));
 if (fileOpener == NULL)
{
    printf("cannot allocating the space in malloc!\n");
    exit(1);
}
    strcpy(fileOpener, username);
const size_t end = strlen(fileOpener) - 1;
if (fileOpener[end] == '\n')
    fileOpener[end] = '\0';
fseek(stdin,0,SEEK_END);
printf("age:");
fgets(age,10,stdin);
fseek(stdin,0,SEEK_END);
printf("Password:");
fgets(password,PASSWORD_LENGTH,stdin);
fseek(stdin,0,SEEK_END);
printf("Account Type:");
fgets(type,CHOICE_LENGTH,stdin);
fseek(stdin,0,SEEK_END);
fputs(username,input);
fputs(password,input);
fputs(type,input);
fclose(input);
FILE *newFile = fopen(fileOpener,"ab+");
char *newAge = malloc(strlen("AGE: ") + strlen(age));
if (newAge == NULL) {
   printf("cannot allocating the space in malloc!\n");
    exit(1);
}
 strcpy(newAge,"AGE: ");
    strcat(newAge,age);
char *newName =malloc(strlen("NAME: ") + strlen(username));
if (newName == NULL) {
   printf("cannot allocating the space in malloc!\n");
    exit(1);
}
strcpy(newName,"NAME: ");
    strcat(newName,username);
fputs(newName,newFile);
fputs(newAge,newFile);
fputs("MEDICATIONS: ",newFile);
fputs("\nVITALS: ",newFile);
fputs("\nHISTORY: ",newFile);
fputs("\nALLERGIES: ",newFile);
fclose(newFile);
printf("Account made.");
}

您的代码存在一些问题。

1:如果你不真正使用它们，则不需要编写a =或ignore =。

2:将 malloc(strlen("things"+ strlen(things))) 更改为 `malloc(strlen("things: ") + strlen(things) )

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