问题描述
#include <stdio.h>
int main(int argc, char** argv) {
int num = 0;
printf("Input: ");
scanf("%d", &num); <<<
printf("%d\n", num);
return 0;
}
scanf(％d"，& num);
Clang-Tidy:"scanf"用于将字符串转换为整数值，但函数不会报告转换错误；考虑改用"strtol"
我用CLion写了一个非常简单的代码，建议我用"strtol"代替"scanf".
I wrote a very simple code with CLion and it recommends me 'strtol' instead of 'scanf'.
但是我只使用整数变量，没有字符串.我不知道为什么会弹出检查消息.
But I'm using only integer variable and there is no strings. I can't figure out why the inspection message pops up.
如何修改此代码?
推荐答案
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <limits.h>
enum { INPUT_SIZE = 30 };
int main () {
char *ptr;
long ret;
char str[INPUT_SIZE];
fgets(str, INPUT_SIZE, stdin);
ret = strtol(str, &ptr, 10);
if( ret == LONG_MAX || ret == LONG_MIN ) {
perror("!! Problem is -> ");
}
else if (ret) {
printf("The number is %ld\n", ret);
}
else {
printf("No number found input is -> %s\n", ptr);
}
return(0);
}
如果未成功，则如果无法进行转换，则 strtol()返回 0 执行.如果正确的值超出可表示的范围值，根据符号， strtol()返回 LONG_MAX 或 LONG_MIN 价值.如果不支持base的值，请 strtol()返回 0 .
If unsuccessful, strtol() returns 0 if no conversion could be performed. If the correct value is outside the range of representable values, strtol() returns LONG_MAX or LONG_MIN, according to the sign of the value. If the value of base is not supported, strtol() returns 0.
如果 strtol()不成功，则将errno设置为以下值之一:
If unsuccessful strtol() sets errno to one of the following values:
错误代码:
EINVAL 不支持base的值.
EINVAL The value of base is not supported.
ERANGE (转换)导致转换溢出.来源: IBM
ERANGE The conversion caused an overflow. Source : IBM
例如，您可以使用 scanf()检查溢出吗?
Can you check overflow using scanf() for example?
Input: 1234 stackoverflow
Output: The number is 1234
Input: 123nowhitespace
Output: The number is 123
Input: number is 123
Output: No number found input is -> number is 123
Input: between123between
Output: No number found input is -> between23between
Input: 9999999999999999999
Output: !! Problem is -> : Result too large
也许是题外话，但 Jonathan Leffler 在他的评论中(在其他主题中)说像错误一样处理警告.
Maybe off-topic but, Jonathan Leffler says in his comments(in another topics) that handle warnings just as errors.
这篇关于CLion建议使用"strtol"代替"scanf"的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！