一般来说，我认为您最好从输入中读取所有内容（当然，在您的缓冲区大小范围内），然后然后验证输入确实是正确的格式.
在您的情况下，您使用 f1f1f 之类的字符串会看到错误，因为您没有读取整个 STDIN 缓冲区。因此，当您再次调用scanf(...) 时，STDIN 内部仍有数据，因此首先读取数据，而不是提示用户输入更多输入。要阅读所有 STDIN，您应该执行以下操作（部分代码从 Paxdiablo 的答案中借用：https://stackoverflow.com/a/4023921/2694511）：
#include <stdio.h>
#include <string.h>
#include <stdlib.h> // Used for strtol
#define OK 0
#define NO_INPUT 1
#define TOO_LONG 2
#define NaN 3 // Not a Number (NaN)
int strIsInt(const char *ptrStr){
// Check if the string starts with a positive or negative sign
if(*ptrStr == '+' || *ptrStr == '-'){
// First character is a sign. Advance pointer position
ptrStr++;
}
// Now make sure the string (or the character after a positive/negative sign) is not null
if(*ptrStr == NULL){
return NaN;
}
while(*ptrStr != NULL){
// Check if the current character is a digit
// isdigit() returns zero for non-digit characters
if(isdigit( *ptrStr ) == 0){
// Not a digit
return NaN;
} // else, we'll increment the pointer and check the next character
ptrStr++;
}
// If we have made it this far, then we know that every character inside of the string is indeed a digit
// As such, we can go ahead and return a success response here
// (A success response, in this case, is any value other than NaN)
return 0;
}
static int getLine (char *prmpt, char *buff, size_t sz) {
int ch, extra;
// Get line with buffer overrun protection.
if (prmpt != NULL) {
printf ("%s", prmpt);
fflush (stdout);
}
if (fgets (buff, sz, stdin) == NULL)
return NO_INPUT;
// If it was too long, there'll be no newline. In that case, we flush
// to end of line so that excess doesn't affect the next call.
// (Per Chux suggestions in the comments, the "buff[0]" condition
// has been added here.)
if (buff[0] && buff[strlen(buff)-1] != '\n') {
extra = 0;
while (((ch = getchar()) != '\n') && (ch != EOF))
extra = 1;
return (extra == 1) ? TOO_LONG : OK;
}
// Otherwise remove newline and give string back to caller.
buff[strlen(buff)-1] = '\0';
return OK;
}
void validate_input(int responseCode, char *prompt, char *buffer, size_t bufferSize){
while( responseCode != OK ||
strIsInt( buffer ) == NaN )
{
printf("Invalid input.\nPlease enter integers only!\n");
fflush(stdout); /* It might be unnecessary to flush here because we'll flush STDOUT in the
getLine function anyway, but it is good practice to flush STDOUT when printing
important information. */
responseCode = getLine(prompt, buffer, bufferSize); // Read entire STDIN
}
// Finally, we know that the input is an integer
}
int main(int argc, char **argv){
char *prompt = "Please Insert X value\n";
int iResponseCode;
char cInputBuffer[100];
int x, y=0;
int *p = &x;
while(y < 5){
iResponseCode = getLine(prompt, cInputBuffer, sizeof(cInputBuffer)); // Read entire STDIN buffer
validate_input(iResponseCode, prompt, cInputBuffer, sizeof(cInputBuffer));
// Once validate_input finishes running, we should have a proper integer in our input buffer!
// Now we'll just convert it from a string to an integer, and store it in the P variable, as you
// were doing in your question.
sscanf(cInputBuffer, "%d", p);
y++;
}
}
作为免责声明/注意：我已经很长时间没有用 C 语言编写了，所以如果这个例子中有任何错误，我提前道歉。我也没有机会在发布之前编译和测试这段代码，因为我现在很着急。