C “什么是”呢;分段故障(堆芯倾倒)“;为什么它会在我的输出中返回?
我试图用一个对fgets的调用来替换包含重复getchar调用的循环 当我尝试键入输入时,我得到了分段错误(核心转储),我不知道这是什么,也不知道为什么会得到它 启动器代码C “什么是”呢;分段故障(堆芯倾倒)“;为什么它会在我的输出中返回?,c,fgets,getchar,strlen,C,Fgets,Getchar,Strlen,我试图用一个对fgets的调用来替换包含重复getchar调用的循环 当我尝试键入输入时,我得到了分段错误(核心转储),我不知道这是什么,也不知道为什么会得到它 启动器代码 /* Example: analysis of text */ #include <stdio.h> #include <string.h> #define MAX 1000 /* The maximum number of characters in a line of input */ ma
/* Example: analysis of text */
#include <stdio.h>
#include <string.h>
#define MAX 1000 /* The maximum number of characters in a line of input */
main()
{
char text[MAX], c;
int i;
int lowercase, uppercase, digits, other;
int length;
puts("Type some text (then ENTER):");
/* Save typed characters in text[]: */
// In ex1.c, please implement the following loop with fgets() and use strlen() to compute the length of the string
//
for (i = 0; i < MAX; i++)
{
text[i] = getchar();
if (text[i] == '\n')
break;
}
length = i;
/* Analyse contents of text[]: */
for (i = lowercase = uppercase = digits = other = 0; i < MAX; i++)
{
c = text[i];
if (c >= 'a' && c <= 'z')
lowercase++;
else if (c >= 'A' && c <= 'Z')
uppercase++;
else if (c >= '0' && c <= '9')
digits++;
else
{
if (c == '\n')
break;
other++;
}
}
puts("\nYou typed:");
printf("A string with %d characters\n", length);
printf("\t%d lower case letters\n", lowercase);
printf("\t%d upper case letters\n", uppercase);
printf("\t%d digits\n", digits);
printf("\t%d others\n", other);
}
/* Example: analysis of text */
#include <stdio.h>
#include <string.h>
#define MAX 1000 /* The maximum number of characters in a line of input */
main()
{
char text[MAX], c;
int i;
int lowercase, uppercase, digits, other;
int length;
puts("Type some text (then ENTER):");
/* Save typed characters in text[]: */
// In ex1.c, please implement the following loop with fgets() and use strlen() to compute the length of the string
//
c = fgets(text, MAX, stdin);
length = strlen(c);
/* Analyse contents of text[]: */
for (i = lowercase = uppercase = digits = other = 0; i < MAX; i++)
{
c = text[i];
if (c >= 'a' && c <= 'z')
lowercase++;
else if (c >= 'A' && c <= 'Z')
uppercase++;
else if (c >= '0' && c <= '9')
digits++;
else
{
if (c == '\n')
break;
other++;
}
}
puts("\nYou typed:");
printf("A string with %d characters\n", length);
printf("\t%d lower case letters\n", lowercase);
printf("\t%d upper case letters\n", uppercase);
printf("\t%d digits\n", digits);
printf("\t%d others\n", other);
}
我的代码
/* Example: analysis of text */
#include <stdio.h>
#include <string.h>
#define MAX 1000 /* The maximum number of characters in a line of input */
main()
{
char text[MAX], c;
int i;
int lowercase, uppercase, digits, other;
int length;
puts("Type some text (then ENTER):");
/* Save typed characters in text[]: */
// In ex1.c, please implement the following loop with fgets() and use strlen() to compute the length of the string
//
for (i = 0; i < MAX; i++)
{
text[i] = getchar();
if (text[i] == '\n')
break;
}
length = i;
/* Analyse contents of text[]: */
for (i = lowercase = uppercase = digits = other = 0; i < MAX; i++)
{
c = text[i];
if (c >= 'a' && c <= 'z')
lowercase++;
else if (c >= 'A' && c <= 'Z')
uppercase++;
else if (c >= '0' && c <= '9')
digits++;
else
{
if (c == '\n')
break;
other++;
}
}
puts("\nYou typed:");
printf("A string with %d characters\n", length);
printf("\t%d lower case letters\n", lowercase);
printf("\t%d upper case letters\n", uppercase);
printf("\t%d digits\n", digits);
printf("\t%d others\n", other);
}
/* Example: analysis of text */
#include <stdio.h>
#include <string.h>
#define MAX 1000 /* The maximum number of characters in a line of input */
main()
{
char text[MAX], c;
int i;
int lowercase, uppercase, digits, other;
int length;
puts("Type some text (then ENTER):");
/* Save typed characters in text[]: */
// In ex1.c, please implement the following loop with fgets() and use strlen() to compute the length of the string
//
c = fgets(text, MAX, stdin);
length = strlen(c);
/* Analyse contents of text[]: */
for (i = lowercase = uppercase = digits = other = 0; i < MAX; i++)
{
c = text[i];
if (c >= 'a' && c <= 'z')
lowercase++;
else if (c >= 'A' && c <= 'Z')
uppercase++;
else if (c >= '0' && c <= '9')
digits++;
else
{
if (c == '\n')
break;
other++;
}
}
puts("\nYou typed:");
printf("A string with %d characters\n", length);
printf("\t%d lower case letters\n", lowercase);
printf("\t%d upper case letters\n", uppercase);
printf("\t%d digits\n", digits);
printf("\t%d others\n", other);
}
非常感谢您的帮助。我也是C语言的新手,所以请尽可能简单地解释一下
改变
长度=strlen(c)代码>至length=strlen(文本)代码>修复了它。谢谢大家!您的错误或至少其中一个错误出现在以下行中:
char text[MAX], c;
// ...
c = fgets(text, MAX, stdin);
length = strlen(c);
fgets
的返回值是指向字符的指针,但您将其存储在字符中,然后尝试将字符值传递给需要指向字符指针的函数。由于char
只有8位宽(在您要编译的任何机器上),指针需要32或64位,因此大部分位丢失,结果是指针无效。如果幸运的话,这将导致程序因分段错误而崩溃
这段代码实际上根本不应该编译。如果您至少没有收到一条警告,说明c
无法保存指向char
的指针,则需要启用更多警告标志。(在gcc
或clang
上,我通常使用-std=c99-Wall-Wextra-Wpedantic-Wconversion
进行编译)然后,至少在学习该语言时,将收到的任何警告视为程序中的错误。更好的是,添加-Werror
(或编译器的等效项),使编译器以这种方式处理它们
最简单的解决方法是消除c
而改为写
fgets( text, MAX, stdin );
length = strlen(text);
问题应该是独立的(参见)。不要发布代码链接,也不要发布代码图像。这意味着您的程序正在尝试读取或写入一个不存在的内存位置。您的代码甚至不应该编译char
和char*
是两种截然不同的类型。打开所有编译器警告,永远不要忽略它们文本将被\0
而不是\n
终止@Stavr00fgets()
读取一行并在其中保留换行符,除非该行长于MAX