#include <stdio.h> #include <errno.h> #include <string.h> extern int errno ; int main () { FILE * pf; int errnum; pf = fopen ("unexist.txt", "rb"); if (pf == NULL) { errnum = errno; fprintf(stderr, "错误号: %d ", errno); perror("通过 perror 输出错误"); fprintf(stderr, "打开文件错误: %s ", strerror( errnum )); } else { fclose (pf); } return 0; }
#include <stdio.h> #include <stdlib.h> main() { int dividend = 20; int divisor = 0; int quotient; if( divisor == 0){ fprintf(stderr, "除数为 0 退出运行... "); exit(-1); } quotient = dividend / divisor; fprintf(stderr, "quotient 变量的值为 : %d ", quotient ); exit(0); }
#include <stdio.h> #include <stdlib.h> main() { int dividend = 20; int divisor = 5; int quotient; if( divisor == 0){ fprintf(stderr, "除数为 0 退出运行... "); exit(EXIT_FAILURE); } quotient = dividend / divisor; fprintf(stderr, "quotient 变量的值为: %d ", quotient ); exit(EXIT_SUCCESS); }