1、函数大全(a 开头)函数名: abort 功 能: 异常终止一个进程 用 法: void abort(void); 程序例: #include #include int main(void) printf(“Calling abort()n“); abort(); return 0; /* This is never reached */ 函数名: abs 功 能: 求整数的绝对值 用 法: int abs(int i); 程序例: #include #include int main(void) int number = -1234; printf(“number: %d absolute
2、value: %dn“, number, abs(number); return 0; 函数名: absread, abswirte 功 能: 绝对磁盘扇区读、写数据 用 法: int absread(int drive, int nsects, int sectno, void *buffer); int abswrite(int drive, int nsects, in tsectno, void *buffer); 程序例: /* absread example */ #include #include #include #include int main(void) int i, s
3、trt, ch_out, sector; char buf512; printf(“Insert a diskette into drive A and press any keyn“); getch(); sector = 0; if (absread(0, 1, sector, exit(1); printf(“Read OKn“); strt = 3; for (i=0; i -1) write(handle, buf, strlen(buf); /* close the file */ close(handle); else printf(“Error opening filen“);
4、 return 0; 函数名: clock 功 能: 确定处理器时间 用 法: clock_t clock(void); 程序例: #include #include #include int main(void) clock_t start, end; start = clock(); delay(2000); end = clock(); printf(“The time was: %fn“, (end - start) / CLK_TCK); return 0; 函数名: closegraph 功 能: 关闭图形系统 用 法: void far closegraph(void); 程序例
5、: #include #include #include #include int main(void) /* request auto detection */ int gdriver = DETECT, gmode, errorcode; int x, y; /* initialize graphics mode */ initgraph( /* read result of initialization */ errorcode = graphresult(); if (errorcode != grOk) /* an error occurred */ printf(“Graphics
6、 error: %sn“, grapherrormsg(errorcode); printf(“Press any key to halt:“); getch(); exit(1); /* terminate with an error code */ x = getmaxx() / 2; y = getmaxy() / 2; /* output a message */ settextjustify(CENTER_TEXT, CENTER_TEXT); outtextxy(x, y, “Press a key to close the graphics system:“); /* wait
7、for a key */ getch(); /* closes down the graphics system */ closegraph(); printf(“Were now back in text mode.n“); printf(“Press any key to halt:“); getch(); return 0; 函数名: clreol 功 能: 在文本窗口中清除字符到行末 用 法: void clreol(void); 程序例: #include int main(void) clrscr(); cprintf(“The function CLREOL clears all
8、 characters from thern“); cprintf(“cursor position to the end of the line within thern“); cprintf(“current text window, without moving the cursor.rn“); cprintf(“Press any key to continue . . .“); gotoxy(14, 4); getch(); clreol(); getch(); return 0; 函数名: clrscr 功 能: 清除文本模式窗口 用 法: void clrscr(void); 程
9、序例: #include int main(void) int i; clrscr(); for (i = 0; i 20; i+) cprintf(“%drn“, i); cprintf(“rnPress any key to clear screen“); getch(); clrscr(); cprintf(“The screen has been cleared!“); getch(); return 0; 函数名: coreleft 功 能: 返回未使用内存的大小 用 法: unsigned coreleft(void); 程序例: #include #include int mai
10、n(void) printf(“The difference between the highest allocated block andn“); printf(“the top of the heap is: %lu bytesn“, (unsigned long) coreleft(); return 0; 函数名: cos 功 能: 余弦函数 用 法: double cos(double x); 程序例: #include #include int main(void) double result; double x = 0.5; result = cos(x); printf(“Th
11、e cosine of %lf is %lfn“, x, result); return 0; 函数名: cosh 功 能: 双曲余弦函数 用 法: dluble cosh(double x); 程序例: #include #include int main(void) double result; double x = 0.5; result = cosh(x); printf(“The hyperboic cosine of %lf is %lfn“, x, result); return 0; 函数名: country 功 能: 返回与国家有关的信息 用 法: struct COUNTR
12、Y *country(int countrycode, struct country *country); 程序例: #include #include #define USA 0 int main(void) struct COUNTRY country_info; country(USA, printf(“The currency symbol for the USA is: %sn“, country_info.co_curr); return 0; 函数名: cprintf 功 能: 送格式化输出至屏幕 用 法: int cprintf(const char *format, argu
13、ment, .); 程序例: #include int main(void) /* clear the screen */ clrscr(); /* create a text window */ window(10, 10, 80, 25); /* output some text in the window */ cprintf(“Hello worldrn“); /* wait for a key */ getch(); return 0; 函数名: cputs 功 能: 写字符到屏幕 用 法: void cputs(const char *string); 程序例: #include
14、int main(void) /* clear the screen */ clrscr(); /* create a text window */ window(10, 10, 80, 25); /* output some text in the window */ cputs(“This is within the windowrn“); /* wait for a key */ getch(); return 0; 函数名: _creat creat 功 能: 创建一个新文件或重写一个已存在的文件 用 法: int creat (const char *filename, int pe
15、rmiss); 程序例: #include #include #include #include int main(void) int handle; char buf11 = “0123456789“; /* change the default file mode from text to binary */ _fmode = O_BINARY; /* create a binary file for reading and writing */ handle = creat(“DUMMY.FIL“, S_IREAD | S_IWRITE); /* write 10 bytes to th
16、e file */ write(handle, buf, strlen(buf); /* close the file */ close(handle); return 0; 函数名: creatnew 功 能: 创建一个新文件 用 法: int creatnew(const char *filename, int attrib); 程序例: #include #include #include #include #include int main(void) int handle; char buf11 = “0123456789“; /* attempt to create a file
17、that doesnt already exist */ handle = creatnew(“DUMMY.FIL“, 0); if (handle = -1) printf(“DUMMY.FIL already exists.n“); else printf(“DUMMY.FIL successfully created.n“); write(handle, buf, strlen(buf); close(handle); return 0; 函数名: creattemp 功 能: 创建一个新文件或重写一个已存在的文件 用 法: int creattemp(const char *filen
18、ame, int attrib); 程序例: #include #include #include int main(void) int handle; char pathname128; strcpy(pathname, “); /* create a unique file in the root directory */ handle = creattemp(pathname, 0); printf(“%s was the unique file created.n“, pathname); close(handle); return 0; 函数名: cscanf 功 能: 从控制台执行
19、格式化输入 用 法: int cscanf(char *format,argument, .); 程序例: #include int main(void) char string80; /* clear the screen */ clrscr(); /* Prompt the user for input */ cprintf(“Enter a string with no spaces:“); /* read the input */ cscanf(“%s“, string); /* display what was read */ cprintf(“rnThe string entere
20、d is: %s“, string); return 0; 函数名: ctime 功 能: 把日期和时间转换为字符串 用 法: char *ctime(const time_t *time); 程序例: #include #include int main(void) time_t t; time( printf(“Todays date and time: %sn“, ctime( return 0; 函数名: ctrlbrk 功 能: 设置 Ctrl-Break 处理程序 用 法: void ctrlbrk(*fptr)(void); 程序例: #include #include #def
21、ine ABORT 0 int c_break(void) printf(“Control-Break pressed. Program aborting .n“); return (ABORT); int main(void) ctrlbrk(c_break); for(;) printf(“Looping. Press to quit:n“); return 0; 函数大全(d 开头)函数名: delay 功 能: 将程序的执行暂停一段时间 (毫秒) 用 法: void delay(unsigned milliseconds); 程序例: /* Emits a 440-Hz tone for 500 milliseconds */ #include
