13-7.txt

c primer 部分习题答案

PE 13-7
 
/* Programming Exercise 13-7a */
/* code assumes that end-of-line immediately precedes end-of-file */
 
#include <stdio.h>
#include <stdlib.h>
#include <console.h>    /* Macintosh adjustment */
 
int main(int argc, char *argv[])
{
    int ch1, ch2;
    FILE * f1;
    FILE * f2;
    
    argc = ccommand(&argv);   /* Macintosh adjustment */  
 
    if (argc != 3)
    {
        printf("Usage: %s file1 file2\n", argv[0]);
        exit(EXIT_FAILURE);
    }
    if ((f1 = fopen(argv[1], "r")) == NULL)
    {
        printf("Could not open file %s for input\n", argv[1]);    
        exit(EXIT_FAILURE);
    }
    if ((f2 = fopen(argv[2], "r")) == NULL)
    {
        printf("Could not open file %s for input\n", argv[2]);    
        exit(EXIT_FAILURE);
    }
    ch1 = getc(f1);
    ch2 = getc(f2);
    
    while (ch1 != EOF || ch2 != EOF)
    {
        while (ch1 != EOF && ch1 != '\n') /* skipped after EOF reached */
        {
            putchar(ch1);
            ch1 = getc(f1);
        }
        if (ch1 != EOF)
        {
            putchar('\n');
            ch1 = getc(f1);
        }
        while (ch2 != EOF && ch2 != '\n') /* skipped after EOF reached */
        {
            putchar(ch2);
            ch2 = getc(f2);
        }
 
        if (ch2 != EOF)
        {
            putchar('\n');
            ch2 = getc(f2);
        }
    }
        
    if (fclose(f1) != 0)
        printf("Could not close file %s\n", argv[1]);    
    if (fclose(f2) != 0)
        printf("Could not close file %s\n", argv[2]);    
        
    return 0;
}
 
/* Programming Exercise 13-7b */
/* code assumes that end-of-line immediately precedes end-of-file */
 
#include <stdio.h>
#include <stdlib.h>
#include <console.h>    /* Macintosh adjustment */
 
int main(int argc, char *argv[])
{
    int ch1, ch2;
    FILE * f1;
    FILE * f2;
    
    argc = ccommand(&argv);   /* Macintosh adjustment */  
 
    if (argc != 3)
    {
        printf("Usage: %s file1 file2\n", argv[0]);
        exit(EXIT_FAILURE);
    }
    if ((f1 = fopen(argv[1], "r")) == NULL)
    {
        printf("Could not open file %s for input\n", argv[1]);    
        exit(EXIT_FAILURE);
    }
    if ((f2 = fopen(argv[2], "r")) == NULL)
    {
        printf("Could not open file %s for input\n", argv[2]);    
        exit(EXIT_FAILURE);
    }
    ch1 = getc(f1);
    ch2 = getc(f2);
    
    while (ch1 != EOF || ch2 != EOF)
    {
        while (ch1 != EOF && ch1 != '\n') /* skipped after EOF reached */
        {
            putchar(ch1);
            ch1 = getc(f1);
        }
        if (ch1 != EOF)
        {
            if (ch2 == EOF)
                putchar('\n');
            else
                putchar(' ');
            ch1 = getc(f1);
        }
        while (ch2 != EOF && ch2 != '\n') /* skipped after EOF reached */
        {
            putchar(ch2);
            ch2 = getc(f2);
        }
 
        if (ch2 != EOF)
        {
            putchar('\n');
            ch2 = getc(f2);
        }
    }
        
    if (fclose(f1) != 0)
        printf("Could not close file %s\n", argv[1]);    
    if (fclose(f2) != 0)
        printf("Could not close file %s\n", argv[2]);    
        
    return 0;
}