函数doc说明文件.doc

stdio.h: I/O functions: getchar() returns the next character typed on the keyboard. putchar() outputs a single character to the screen. printf() as previously described scanf() as previously described string.h: String functions strcat() concatenates a copy of str2 to str1 strcmp() compares two strings strcpy() copys contents of str2 to str1 ctype.h: Character functions isdigit() returns non-0 if arg is digit 0 to 9 isalpha() returns non-0 if arg is a letter of the alphabet isalnum() returns non-0 if arg is a letter or digit islower() returns non-0 if arg is lowercase letter isupper() returns non-0 if arg is uppercase letter time.h: Time and Date functions time() returns current calender time of system difftime() returns difference in secs between two times clock() returns number of system clock cycles since program execution stdlib.h:Miscellaneous functions malloc() provides dynamic memory allocation, covered in future sections rand() as already described previously srand() used to set the starting point for rand()  輸出入函數 輸出/入設備 輸出/入指令設備 緩衝區 緩衝區滿 或EOF 填入緩衝區 暫未輸出入 直接輸出入至設備 緩衝區輸出入, 只有緩衝區滿或EOF符號(如鍵盤需要輸入enter鍵)才可正常輸出入 stdio.h: I/O functions: 緩衝區輸入 scanf() 由輸入緩衝區輸入格式化資料 語法: scanf( “格式字串 %d, ...%c ...等等”, 變數位址, .... ) 範例 Int i ; Int * ip; Ip=(int*) malloc(sizeof(int)); scanf( “%d %d”, i, ip); printf(“%d %d\n”, i,*ip ); getchar()由輸入設備之緩衝區讀得一字元, 若輸入設備為鍵盤, 需要輸入enter鍵才能將鍵盤輸入至緩衝區 語法: 字元變數=getchar(); 範例 char ch; ch=getchar(); char *chp; chp=(int*) malloc(sizeof(int)); *chp =getchar(); printf(“%c %c\n”, ch,*chp ); 非緩衝區輸入 getch(): 由鍵盤取得一字元, 該字元不顯示於營幕 語法: 字元變數=getch(); 範例 char ch; ch =getch(); char *chp; chp=(int*) malloc(sizeof(int)); *chp =getch(); printf(“%d %d\n”, ch,*chp ); getche():由鍵盤取得一字元, 該字元顯示於營幕 語法: 字元變數=getche(); 範例 char