c primer plus 习题答案(6)

p376.7

A方案

 1 #include<stdio.h>

 2 #include<stdlib.h>

 3 #define LEN 40

 4 void rank(FILE *, FILE *);

 5 int main(void)

 6 {

 7     FILE *fp, *fc;

 8     int ch, bp;

 9     char file1[LEN], file2[LEN];

10 

11     puts("enter file1 name");

12     if((fp=fopen(gets(file1), "r"))==NULL){

13         fputs("can't open", stdout);

14         exit(1);

15     }

16 

17     puts("enter file2 name");

18     if((fc=fopen(gets(file2), "r"))==NULL){

19         fputs("can't open", stdout);

20         exit(2);

21     }

22 

23     rank(fp, fc);

24     if((fclose(fp)!=0)||(fclose(fc)!=0))

25         puts("error in closing files");

26 

27     system("pause");

28     return 0;

29 }

30 

31 void rank(FILE *fp, FILE *fc)

32 {

33     int ch, bp;

34     while(1){

35         while(((ch=getc(fp))!='\n')&&ch!=EOF)

36             putc(ch, stdout);

37         if(ch=='\n')

38             putc(ch, stdout);

39         while(((bp=getc(fc))!='\n')&&bp!=EOF)

40             putc(bp, stdout);

41         if(ch=='\n')

42             putc(bp, stdout);

43         if((ch==EOF)&&(bp==EOF))

44             break;

45     }

46 }

B方案

 1 #include<stdio.h>

 2 #include<stdlib.h>

 3 #define LEN 40

 4 void rank(FILE *, FILE *);

 5 int main(void)

 6 {

 7     FILE *fp, *fc;

 8     int ch, bp;

 9     char file1[LEN], file2[LEN];

10 

11     puts("enter file1 name");

12     if((fp=fopen(gets(file1), "r"))==NULL){

13         fputs("can't open", stdout);

14         exit(1);

15     }

16 

17     puts("enter file2 name");

18     if((fc=fopen(gets(file2), "r"))==NULL){

19         fputs("can't open", stdout);

20         exit(2);

21     }

22 

23     rank(fp, fc);

24     if((fclose(fp)!=0)||(fclose(fc)!=0))

25         puts("error in closing files");

26 

27     system("pause");

28     return 0;

29 }

30 

31 void rank(FILE *fp, FILE *fc)

32 {

33     int ch, bp;

34     while(1){

35         while(((ch=getc(fp))!='\n')&&ch!=EOF)

36             putc(ch, stdout);

37         while(((bp=getc(fc))!='\n')&&bp!=EOF)

38             putc(bp, stdout);

39         if((bp=='\n')||(ch=='\n'))

40             printf("\n");

41         if((ch==EOF)&&(bp==EOF))

42             break;

43     }

44 }

p376.8

 1 #include<stdio.h>

 2 #include<stdlib.h>

 3 #define LEN 40

 4 int main(int argc, char *argv[])

 5 {

 6     FILE *fp, *fc, *fd[LEN];

 7     char name1[LEN], name2[LEN];

 8     int ch, bp, count[2]={0}, i, num[LEN]={0};

 9     if(argc==2){

10         puts("enter file1 name");

11         if((fp=fopen(gets(name1), "r"))==NULL)

12             fputs("can't open", stderr);

13         puts("enter file1 name");

14         if((fc=fopen(gets(name2), "r"))==NULL)

15             fputs("can't open", stderr);

16 

17         while((ch=getc(fp))!=EOF)

18             if(ch==argv[1][0])

19                 count[0]++;

20         while((bp=getc(fc))!=EOF)

21             if(bp==argv[1][0])

22                 count[1]++;

23         

24         printf("%s has %d %c\n", name1, count[0], *argv[1]);

25         printf("%s has %d %c\n", name2, count[1], *argv[1]);

26     }

27 

28     for(i=2; i<argc; i++){

29         if((fd[i]=fopen(argv[i], "r"))==NULL){

30             fputs("can't open\n", stderr);

31             continue;

32         }

33         while((ch=getc(fd[i]))!=EOF)

34             if(ch==*argv[1])

35                 num[i]++;

36         printf("%s has %d %c\n", argv[i], num[i], *argv[1]);

37     }

38 

39     system("pause");

40     return 0;

41 }

p376.10

 1 #include<stdio.h>

 2 #include<stdlib.h>

 3 #define LEN 40

 4 int main(void)

 5 {

 6     FILE *fp;

 7     char name[LEN];

 8     long offset;

 9     int ch;

10 

11     puts("enter the file name");

12     if((fp=fopen(gets(name), "r"))==NULL){

13         fprintf(stderr, "can't open\n");

14         exit(1);

15     }

16     puts("enter an offset of file(q to quit)");

17     while(scanf("%ld", &offset)==1){

18         fseek(fp, offset, SEEK_SET);

19         while(((ch=getc(fp))!='\n')&&ch!=EOF&&ch!='\r')

20             fprintf(stdout, "%c", ch);

21         if(ch==EOF)

22             exit;

23         printf("\n");

24         puts("enter an offset of file(q to quit)");

25     }

26 

27     fclose(fp);

28     system("pause");

29     return 0;

30 }