C编程读取多行并暂停，直到按下键盘上的任意键

Question

我是 C 编程的新手。我希望我能解释我的问题。我正在尝试开发一个程序来读取 binary 文件并转换为 ASCII 模式。这没有任何问题。但我要做的是询问用户，他/她想要读取多少行(例如 20 行)，然后只显示二进制文件中的 20 行，并要求用户按任意键继续。按任意键后，再次显示该文件的下 20 行，依此类推。

我尝试使用 getch() 和 getchar() 但这只对一行有效。

我的以下代码可能有助于正确解释。请帮我解决这个问题。提前谢谢你。

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

void header(); //Title function declaration

int main(int argc, char *argv[])
{
    FILE *fp; // File pointer declaration
    int i, j;
    unsigned char buffer[17]; // Trying to get value for 16 bites each

    fp = fopen(argv[1], "rb"); 
    if (argc == 1) { // Condition for if user didnt specify file name
        /* Assume that argv[0] is the program name */
        printf("usage: %s, <file_name>", argv[0]);
        return 0;
    }

    if (fp == NULL) { // condition if there is no file 
        fprintf(stderr, "File Open error (%s) , error = %d", argv[1], errno);
        exit(1);
    }

    else
    {
        header(); // Calling function header

        int read = 0;
        int address = 0;
        while ((read = fread(buffer, 1, 16, fp)) > 0)
        {
            printf("%08X", address); 
            printf(" ");
            address += 16;

            for (i = 0; i < read; i++)
            {
                if (i == 8) {
                    if (buffer[i] != NULL)
                        printf("-");
                }
                else {

                    printf(" ");
                }
                printf("%02X", buffer[i]);
            }

            int space = 16 - read;

            if (space != 0) {

                for (int x = 0; x < space; x++) {
                    int y = read + (x - buffer[x]);
                    printf("   ");
                }
            }
            printf("  ");
            for (j = 0; j < read; j++)
            {
                if (buffer[j] == NULL) {
                    printf(".");
                }
                if (isprint(buffer[j])) {
                    printf("%c", buffer[j]);
                    //fflush(stdin);
                }
                else {
                    if (buffer[j] != NULL) {
                        printf(".");
                    }
                }
            }
            printf("\n");

        }

    }
    fclose(fp);

    return 0;
}

void header() {
    printf("ADDRESS  ");

    for (int i = 0X00; i <= 0X0F; i++)
    {
        if (i == 8) {
            printf("-");
        }
        else
        {
            printf(" ");
        }
        printf("%02X", i);
    }
    printf("  0123456789ABCDEF \n");
    printf("----------------------------------------------------------------------------\n");

}

And output should be like Sample

Answer 1

您需要将读取和打印逻辑包围在循环中。

int read = 0;
int address = 0;
int numLines = 0;

printf("How many lines you want to print?");
scanf("%d", &numLines);
do {

       for(int i = 0; i<numLines; i++)
       {
                if ((read = fread(buffer, 1, 16, fp)) > 0)
                {
                      ....... //your printing logic here
                }
       }

       /*Flush input stream in case \n left out*/
       int c;
       while ((c = getchar()) != '\n' && c != EOF) { }

       printf("press Any key to continue\n");
       getchar();
 } while(read>0);