Question

我的目标很简单。要求用户提供包含大写/小写字母，数字和标点符号的简单文本文件。然后取出文件，打开它，扫描每个上述元素，保持每个元素的计数。最后，输出每个的总数（即包含的大写字母总数，小写字母总数，总数字和总标点符号）。

不幸的是，我的问题并非如此简单。我真的很困惑C（如在概念和语法中）将输入文件传递给fgetc之类的函数然后测试它以增加计数器的方式。我的程序崩溃了，为什么我的想法很低落。我想我最初的问题是，它为什么会崩溃？我的代码如下;

#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>


int main()
{
    char Character = 0;
    int words = 0;
    int upper_case = 0;
    int lower_case = 0;
    int punctuation = 0;
    int digits = 0;
    int entered_words = 0;
    char user_filename[100];
    char user_filecontent[100];



    printf("Enter the filename of the file containing text and/or digits:\n");
    printf("(hit the Enter key when done)\n");
    gets(user_filename);

    FILE *fp;
    fp = fopen (user_filename, "r");


    if (fp == NULL)
    {
        printf("\nError, Unable to open the file for reading\n");
    }


    while((fp = fgetc(fp)) != EOF)
    {


            while((Character=fgetc(fp)) != '\n');
            {

                if (isalnum (Character))
                {
                    if (!entered_words)
                    {
                        entered_words = 1;
                        words++;
                    }
                }


                else
                {
                    if (entered_words)
                    {
                        entered_words = 0;
                    }
                }


                if (isupper(Character))
                {
                    upper_case++;
                }


                else if (islower(Character))
                {
                    lower_case++;
                }


                else if (isdigit(Character))
                {
                    digits++;
                }


                else if (ispunct(Character))
                {
                    punctuation++;
                }

            }

    fclose(fp);
    }

    printf("Total number of words is %d.\n", words);
    printf("Total number of digits are %d.\n", digits);
    printf("Total number of uppercase letters is %d.\n", upper_case);
    printf("Total number of lowercase letters is %d.\n", lower_case);
    printf("Total number of punctuation characters is %d.\n", punctuation);

return 0;
}

Answer 1

#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>


int main()
{
    char Character = 0;
    int words = 0;
    int upper_case = 0;
    int lower_case = 0;
    int punctuation = 0;
    int digits = 0;
    int entered_words = 0;
    char user_filename[100];
    char user_filecontent[100];



    printf("Enter the filename of the file containing text and/or digits:\n");
    printf("(hit the Enter key when done)\n");
    gets(user_filename);

    FILE *fp;
    fp = fopen (user_filename, "r");


    if (fp == NULL)
    {
        printf("\nError, Unable to open the file for reading\n");
    }


    while((Character = fgetc(fp)) != EOF)
    {

                if (isalnum (Character))
                {
                    if (!entered_words)
                    {
                        entered_words = 1;
                        words++;
                    }
                }


                else
                {
                    if (entered_words)
                    {
                        entered_words = 0;
                    }
                }


                if (isupper(Character))
                {
                    upper_case++;
                }


                else if (islower(Character))
                {
                    lower_case++;
                }


                else if (isdigit(Character))
                {
                    digits++;
                }


                else if (ispunct(Character))
                {
                    punctuation++;
                }
    }

    fclose(fp);

    printf("Total number of words is %d.\n", words);
    printf("Total number of digits are %d.\n", digits);
    printf("Total number of uppercase letters is %d.\n", upper_case);
    printf("Total number of lowercase letters is %d.\n", lower_case);
    printf("Total number of punctuation characters is %d.\n", punctuation);

return 0;
}

我删除了内部while循环并将fclose函数调用移到循环外部。

Answer 2

您正在考试时FILE *fp fgetc分配while((fp = fgetc(fp)) != EOF)的结果：

fp

这可能是导致崩溃的原因。调用fopen后，FILE *是文件的句柄，之后您只需将其传递给fgetc的函数，例如fclose和{{ 1}}。

此外，您正在调用fgetc两次：一次在while测试中，然后在另一个while测试中紧随其后。即使您修复了fp问题，也会以这种方式丢失字符。你为什么需要内循环？

Answer 3

man fgetc告诉

fgetc（）从流中读取下一个字符并将其作为一个返回 unsigned char转换为int，或EOF在文件末尾或错误。

您必须使用int变量来存储此结果

如何输入文件并使用它来计算大写/小写字母，数字和标点符号？

3 个答案: