1 #include <stdio.h> 2 #include <stdlib.h> 3 4 int main(void) 5 { 6 FILE *fp; 7 /* char arr[100]; */ 8 9 //write sth to T.txt 10 fp = fopen("T.txt","w"); 11 if(fp == NULL) 12 { 13 puts("File open failed."); 14 exit(EXIT_FAILURE); 15 } 16 fprintf(fp,"%s","How are you doing?\n"); 17 fclose(fp); 18 19 //output T.txt 20 fp = fopen("T.txt","r"); 21 if(fp == NULL) 22 { 23 puts("File open failed."); 24 exit(EXIT_FAILURE); 25 } 26 /* if(fgets(arr,100,fp) != NULL) 27 puts(arr); */ 28 for(;;) 29 { 30 if(feof(fp)) 31 break; 32 putchar(getc(fp)); 33 } 34 fclose(fp); 35 36 return 0; 37 }