在getchar（）函数之后，Scanf（）失败。 [英] Scanf() fails after getchar() function.

问题描述

我正在尝试编写一个程序，当用户将每个字符输入控制台时，我可以动态增加字符指针的大小。这是我尝试这个概念的程序:(一个动态分配的字符串）

I am trying to write a program where I could dynamically increase the size of a character pointer as the user enters each character into the console. Here is the program where I am attempting this concept: (A dynamically allocated string)

#include<stdio.h>
#include<conio.h>
#include<stdlib.h>
#include<string.h>

struct Structure
{
	char *buf;
	int intvar1, intvar2;
};

char *getdt()
{
	char *chr = (char*)malloc(1);
	int i = 0;
	char ch = getchar();
	while (ch != '\n')
	{
		chr[i] = ch;
		ch = getchar();
		chr = (char *)realloc(chr, (++i) + 1);
	}
	chr[i] = '\0';

	return chr;
}

void main()
{

	int elmts = 0, i = 0;
	Structure * strt;
	scanf("%d", &elmts);

	strt = (Structure*)malloc(sizeof(Structure)*elmts);

	for (i = 0; i < elmts; i++)
	{
		strt[i].buf = getdt();
		scanf("%d", &strt[i].intvar1);
		scanf("%d", &strt[i].intvar2);

	}

	for (i = 0; i < elmts; i++)
	{
		printf("%s %d %f", strt[i].buf, strt[i].intvar1, strt[i].intvar2);
	}


	free(strt);
	getch();

}

[ getdt（）函数应该从用户那里得到一个字符串。]



唯一的问题是使用以下片段：

[The getdt() function is supposed to get a string from the user.]

The only trouble is with the following fragment:

strt[i].buf = getdt();
		scanf("%d", &strt[i].intvar1);
		scanf("%d", &strt[i].intvar2);

我可以在<$ c $正确检索字符串c> strt [i] .buf = getdt（），但是连续的scanf（）跳过并直接进入下面的for循环。



经过一番研究后，我怀疑组合getchar（）和scanf（）将是罪魁祸首。但我真的不明白导致故障的原因。


可以建议更正吗？



我尝试过：



这就是我的尝试：

where I am able to retrieve a string properly at strt[i].buf = getdt(), but the successive scanf() 's skips and goes directly to the for-loop beneath.

After some researching I suspect the combination getchar() and scanf() would be the culprit. But I really dont understand what causes the malfunction.

Could any corrections be suggested ?

What I have tried:

This is what I have tried:

for (i = 0; i < n; i++)
{
strt[i].buf = getdt();
char tmp[10],tmp1[10], *tp,*tq;
getss(tmp);
strt[i].intvar1 = strtol(tmp,&tp,10);
gets(tmp1)
strt[i].intvar2 = strtol(tmp1,&tq,10)
}

这些努力都是徒劳的。

These efforts were simply in vain.

推荐答案

为什么要为自己复杂化？使用获取，_getws [ ^ ]读取字符串。这是 scanf 的常见问题，它与其他控制台字符输入调用无关; 获取应该避免这个问题，因为它会清除输入缓冲区。

Why complicate things for yourself? Use gets, _getws[^] to read a string. This is a common problem with scanf, it does not fir well with other console character input calls; gets should avoid this problem as it clears the input buffer.

这篇关于在getchar（）函数之后，Scanf（）失败。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IT屋！