1:  // file error handling 
2:  #include <stdio.h> 
3:   
4:  #define ERR_OPEN_1 11 
5:  #define ERR_OPEN_2 12 
6:  #define ERR_READ 13 
7:  #define ERR_WRITE 14 
8:   
9:  int f_err_report(int mode) { 
10:   if(mode==ERR_OPEN_1) printf("error opening file1n"); 
11:   if(mode==ERR_OPEN_2) printf("error opening file2n"); 
12:   else if(mode==ERR_READ) printf("error reading from file"); 
13:   else if(mode==ERR_WRITE) printf("error writing to file"); 
14:   exit(1); 
15:  } 
16:   
17:  int main(int argc, char *argv[]) 
18:  { 
19:   if(argc<3) { printf("%s <file1> <file2>n",argv[0]); exit(1); } 
20:   char ch; 
21:   FILE *fp,*fp2; 
22:   if((fp=fopen(argv[1],"r"))==NULL) f_err_report(ERR_OPEN_1); 
23:   if((fp2=fopen(argv[2],"w"))==NULL) f_err_report(ERR_OPEN_2); 
24:   while(!feof(fp)) { 
25:    ch=getc(fp); 
26:    if(ferror(fp)) f_err_report(ERR_READ); 
27:    if(!feof(fp)) 
28:    putc(ch,fp2); 
29:    else break; 
30:    if(ferror(fp)) f_err_report(ERR_WRITE); 
31:   } 
32:   fclose(fp); 
33:   fclose(fp2); 
34:   return 0; 
35:  } 
36: