c语言 13-11、13-12
1、13-11
#include <stdio.h> int main(void) { FILE *fp; int i; double b[10]; double a[] = {0.1,1.1,2.1,3.1,4.1,5.1,6.1,7.1,8.1,9.1}; if((fp = fopen("tmp.bin", "wb")) == NULL) printf("\aFile open failed.\n"); else { fwrite(a, sizeof(double), 10, fp); fclose(fp); } if((fp = fopen("tmp.bin", "rb")) == NULL) printf("\aFile open failed.\n"); else { fread(b, sizeof(double), 10, fp); fclose(fp); for(i = 0; i < 10; i++) { printf("b[%d] = %.2f.\n", i, b[i]); } } return 0; }
2、13-12
#include <stdio.h> #include <time.h> void get_data(void) { FILE *fp; int x[6]; if((fp = fopen("time.bin", "rb")) == NULL) printf("\aThe program is running for the first time.\n"); else { fread(x, sizeof(int), 6, fp); printf("The last time the program ran is: %d-%d-%d; %d-%d-%d\n", x[0], x[1], x[2], x[3],x[4],x[5]); fclose(fp); } } void put_data(void) { FILE *fp; time_t current = time(NULL); struct tm *timer = localtime(¤t); int tmp[6] = {timer -> tm_year + 1900, timer -> tm_mon + 1, timer -> tm_mday, timer -> tm_hour, timer -> tm_min, timer -> tm_sec}; if((fp = fopen("time.bin", "wb")) == NULL) printf("\aFile open failed.\n"); else { fwrite(tmp, sizeof(int), 6, fp); fclose(fp); } } int main(void) { get_data(); put_data(); return 0; }