1 /*
2 * 需求描述：分别使用文件IO，标准字符、标准行、标准块IO实现文本文件的拷贝功能
3 * 思考，如果是普通的图片、视频文件，上述拷贝哪些可以用，哪些不可以用
4 * */
5 #include <stdio.h>
6 #include <sys/types.h>
7 #include <sys/stat.h>
8 #include <fcntl.h>
9 #include <unistd.h>
10
11
12
13 /*
14 * 利用文件IO的方式，实现2个文件的拷贝
15 * */
16 int copy_by_fileIO(const char *dest_file_name, const char *src_file_name) {
17 int fd1,fd2;
18 int len;
19
20 //打开文件
21 fd1 = open(src_file_name,O_RDONLY);
22 fd2 = open(dest_file_name,O_WRONLY);
23
24 //获得文件大小，并且将当前位置移到开头
25 len = lseek(fd1, 0, SEEK_END);
26 lseek(fd1,0,SEEK_SET);
27
28 unsigned char buf[len];
29
30 //读取fd1中的内容
31 read(fd1,&buf,len);
32
33 //写入内容到fd2
34 write(fd2,&buf,len);
35
36 //关闭文件
37 close(fd1);
38 close(fd2);
39 }
40
41 /*
42 * 利用标准IO的字符IO，实现2个文件的字节拷贝
43 * */
44 int copy_by_char(const char *dest_file_name, const char *src_file_name) {
45 FILE *fp1,*fp2;
46 int ch;
47
48 fp1 = fopen(src_file_name,"r");
49 fp2 = fopen(dest_file_name,"w");
50
51 ch = fgetc(fp1);
52
53 while(ch != EOF){
54 fputc(ch,fp2);
55 ch = fgetc(fp1);
56 }
57
58 fclose(fp1);
59 fclose(fp2);
60 }
61
62 /*
63 * 利用标准IO的行IO，实现2个文件的按行拷贝
64 * */
65 int copy_by_line(const char *dest_file_name, const char *src_file_name) {
66 FILE *fp1,*fp2;
67 char *res;
68 char buf[1024];
69
70 fp1 = fopen(src_file_name,"r");
71 fp2 = fopen(dest_file_name,"w");
72
73 res = fgets(buf,sizeof(buf),fp1);
74
75 while(res){
76 fputs(buf,fp2);
77 res = fgets(buf,sizeof(buf),fp1);
78 }
79
80 fclose(fp1);
81 fclose(fp2);
82 }
83
84 /*
85 * 利用标准IO的块IO，实现2个文件的块拷贝
86 * */
87 int copy_by_block(const char *dest_file_name, const char *src_file_name) {
88 FILE *fp1,*fp2;
89 char res[3] = {0};
90 int len;
91
92 fp1 = fopen(src_file_name,"r");
93 fp2 = fopen(dest_file_name,"w");
94
95 fseek(fp1,0,SEEK_END);
96 len = ftell(fp1);
97 fseek(fp1,0,SEEK_SET);
98
99 printf("len:%d",len);
100 for(int i=0;i<len;i++) {
101 fread(res, sizeof(char), 1, fp1);
102 fwrite(res, sizeof(char), 1, fp2);
103 }
104 fclose(fp1);
105 fclose(fp2);
106 }
107
108 int main() {
109 char *src_file_path = "./profile";
110 char *dest_file_path = "./test_profile";
111 copy_by_block(dest_file_path,src_file_path);
112 return 0;
113 }
