[C]File merge

// 두개의 파일을 읽어서 하나의 파일로 합치는 코드 

01: /*
02:  *      description : 두 개의 파일을 읽어서 merge
03:  */
04: 
05: 
06: #include <stdio.h>
07: 
08: #define FILEREAD 4096   // buffer size define
09: 
10: void main(void)
11: {
12: 
13:         FILE *fpR1, *fpR2, *fpW;
14:         char buff[FILEREAD];
15:         int len;
16: 
17:         // first file read
18:         fpR1 = fopen("C:\\test.exe","rb");
19:         if(fpR1 == NULL)
20:         {
21:                 perror("first file read fail");
22:                 return;
23:         }
24: 
25:         // second file read
26:         fpR2 = fopen("C:\\test2.exe","rb");
27:         if(fpR2 == NULL)
28:         {
29:                 perror("second file read fail");
30:                 fcloseall();
31:                 return;
32:         }
33: 
34:         // new file write
35:         fpW = fopen("C:\\merged.exe","w+b");
36:         if(fpW == NULL)
37:         {
38:                 perror("write fail");
39:                 fcloseall();
40:                 return;
41:         }
42: 
43:         // get the EOF of first file and write the new file
44:         while(!feof(fpR1))
45:         {
46:                 len = fread(buff,1,FILEREAD,fpR1);
47: 
48:                 if(ferror(fpR1))
49:                 {
50:                         perror("read fail first file");
51:                         fcloseall();
52:                         return;
53:                 }
54: 
55:                 // write first file
56:                 if(len > 0)
57:                 {
58:                         fwrite(buff,1,len,fpW);
59:                         if(ferror(fpW))
60:                         {
61:                                 perror("write fail first file");
62:                                 fcloseall();
63:                                 return;
64:                         }
65:                 }
66:         }
67: 
68: 
69:         // get the EOF of second file and write the new file
70:         while(!feof(fpR2))
71:         {
72:                 len = fread(buff,1,FILEREAD,fpR2);
73: 
74:                 if(ferror(fpR2))
75:                 {
76:                         perror("read fail second file");
77:                         fcloseall();
78:                         return;
79:                 }
80:                 
81:                 // write second file
82:                 if(len > 0)
83:                 {
84:                         fwrite(buff,1,len,fpW);
85:                         if(ferror(fpW))
86:                         {
87:                                 perror("write fail second file");
88:                                 fcloseall();
89:                                 return;
90:                         }
91:                 }
92:         }
93: 
94:         fcloseall();
95: 
96:         puts("file merged!");
97: }