查看: 2061|回复: 1

函数大全(e开头)

字体大小: 正常放大

韩冰

823 主题	3 听众	4048 积分

我的地盘我做主

该用户从未签到

电梯直达

1^#

发表于 2004-10-4 03:01 |只看该作者 |倒序浏览

|招呼Ta 关注Ta

<

align=center>函数大全(e开头)


<

>函数名: ecvt 
功能: 把一个浮点数转换为字符串
用法: char ecvt(double value, int ndigit, int *decpt, int *sign);
程序例: 
<

>#include <STDLIB.H>
#include <STDIO.H>
#include <CONIO.H>
<

>int main(void)
{
char *string;
double value;
int dec, sign;
int ndig = 10; 
<

>clrscr();
value = 9.876;
string = ecvt(value, ndig, &dec, &sign);
printf("string = %s dec = %d \
sign = %d\n", string, dec, sign); 
<

>value = -123.45;
ndig= 15;
string = ecvt(value,ndig,&dec,&sign);
printf("string = %s dec = %d sign = %d\n",
string, dec, sign);

<

>value = 0.6789e5; /* scientific
notation */
ndig = 5;
string = ecvt(value,ndig,&dec,&sign);
printf("string = %s dec = %d\
sign = %d\n", string, dec, sign); 
<

>return 0;
} 


<

>函数名: ellipse 
功能: 画一椭圆
用法: void far ellipse(int x, int y, int stangle, int endangle,
int xradius, int yradius);
程序例: 
<

>#include <GRAPHICS.H>
#include <STDLIB.H>
#include <STDIO.H>
#include <CONIO.H>
<

>int main(void)
{
/* request auto detection */
int gdriver = DETECT, gmode, errorcode;
int midx, midy;
int stangle = 0, endangle = 360;
int xradius = 100, yradius = 50; 
<

>/* initialize graphics, local variables */
initgraph(&gdriver, &gmode, ""); 
<

>/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk)
/* an error occurred */
{
printf("Graphics error: %s\n",
grapherrormsg(errorcode));
printf("

ress any key to halt:");
getch();
exit(1);
/* terminate with an error code */
} 
<

>midx = getmaxx() / 2;
midy = getmaxy() / 2;
setcolor(getmaxcolor()); 
<

>/* draw ellipse */
ellipse(midx, midy, stangle, endangle,
xradius, yradius); 
<

>/* clean up */
getch();
closegraph();
return 0;
} 


<

>函数名: enable 
功能: 开放硬件中断
用法: void enable(void);
程序例: 
<

>/* ** NOTE:
This is an interrupt service routine. You can NOT compile this program
with Test Stack Overflow turned on and get an executable file which will
operate correctly.
*/ 
<

>#include <STDIO.H>
#include <DOS.H>
#include <CONIO.H>
<

>/* The clock tick interrupt */
#define INTR 0X1C 
<

>void interrupt ( *oldhandler)(void); 
<

>int count=0; 
<

>void interrupt handler(void)
{
/*
disable interrupts during the handling of the interrupt
*/
disable();
/* increase the global counter */
count++;
/*
re enable interrupts at the end of the handler
*/
enable();
/* call the old routine */
oldhandler();
} 
<

>int main(void)
{
/* save the old interrupt vector */
oldhandler = getvect(INTR); 
<

>/* install the new interrupt handler */
setvect(INTR, handler); 
<

>/* loop until the counter exceeds 20 */
while (count < 20)
printf("count is %d\n",count); 
<

>/* reset the old interrupt handler */
setvect(INTR, oldhandler); 
<

>return 0;
} 


<

>函数名: eof 
功能: 检测文件结束
用法: int eof(int *handle);
程序例: 
#include <SYS\STAT.H>
#include <STRING.H>
#include <STDIO.H>
#include <FCNTL.H>
#include <IO.H>
int main(void)
{
int handle;
char msg[] = "This is a test";
char ch; 
/* create a file */
handle = open("DUMMY.FIL",
O_CREAT | O_RDWR,
S_IREAD | S_IWRITE); 
/* write some data to the file */
write(handle, msg, strlen(msg)); 
/* seek to the beginning of the file */
lseek(handle, 0L, SEEK_SET); 
/*
reads chars from the file until hit EOF
*/
do
{
read(handle, &ch, 1);
printf("%c", ch);
} while (!eof(handle)); 
close(handle);
return 0;
}


函数名: exec... 
功能: 装入并运行其它程序的函数
用法: int execl(char *pathname, char *arg0, arg1, ..., argn, NULL);
int execle(char *pathname, char *arg0, arg1, ..., argn, NULL,
char *envp[]);
int execlp(char *pathname, char *arg0, arg1, .., NULL);
int execple(char *pathname, char *arg0, arg1, ..., NULL,
char *envp[]);
int execv(char *pathname, char *argv[]);
int execve(char *pathname, char *argv[], char *envp[]);
int execvp(char *pathname, char *argv[]);
int execvpe(char *pathname, char *argv[], char *envp[]);
程序例: 
/* execv example */
#include <PROCESS.H>
#include <STDIO.H>
#include <ERRNO.H>
void main(int argc, char *argv[])
{
int i; 
printf("Command line arguments:\n");
for (i=0; i<ARGC; printf("[%2d] : %s\n", i, argv); - l5 j7 B2 v- { z# I9 K8 P8 T
printf("About to exec child with arg1 arg2 ...\n"); 8 `/ Z( H8 q. U9 a$ h9 l
execv("CHILD.EXE", argv); 
* b6 I7 r: P" dperror("exec error"); 
5 p0 z3 d6 j4 lexit(1);
- d S: i! x. g. ~* i} 5 _+ s& N; K% E

1 I2 n; P/ j3 K# \/ ~
+ Q! l# D+ s2 S$ ?0 W" y4 N1 m' t* E函数名: exit 
7 H; P4 ]* F: v8 {2 r7 }功能: 终止程序
; |4 c8 c- r5 l: p用法: void exit(int status);
1 n/ b6 }, C" |: p0 q! v% S% q程序例: 
. M: \4 u( _$ v" E6 f+ u#include <STDLIB.H>
/ ^1 Q+ _3 }) h5 D3 V0 d: c5 r#include <CONIO.H>) g& o8 S- \1 A8 j' v" Y5 j
#include <STDIO.H>& h( [* |. @1 V9 b9 F
int main(void) $ I: s0 s9 Z' i% d' M, Y/ N
{
; [7 R. }4 \. _: aint status; " L9 B+ j/ ]9 `! M" E
printf("Enter either 1 or 2\n");
! Q. {9 \+ n i! Vstatus = getch(); $ r8 e7 z3 ]8 F" W" g/ m; _
/* Sets DOS errorlevel */
! S7 F- ^7 g( {exit(status - '0'); ) w/ K# |) G# s! K
/* Note: this line is never reached */
$ B0 J( {/ z$ {) L4 Zreturn 0;
! p: B% E7 {- V# N% O R( f) {! J}
 ^7 |# }: d0 D |, a: W# Q& a! m; W) l y* ?, j9 F

) {! Z1 |, [8 H! ?$ m: X. m函数名: exp 
 [4 W5 v" e6 f/ \功能: 指数函数
' l+ v4 a3 o) E# r. @用法: double exp(double x);
# x& J* ?5 p' W. I @0 ~% U1 `程序例: 
4 i1 Y% x4 r% P$ ]% U#include <STDIO.H>0 p2 I( T( G6 ^
#include <MATH.H>! k0 a9 n- n$ O, ?
int main(void)
6 B; {& t+ Z8 V, i, L# p, ]{ 9 P7 N, F2 J3 N4 y& N
double result; 6 z- W ?3 N) O- ^2 l
double x = 4.0; % k) G$ X* |( G7 `2 G: ^. z% v0 p
result = exp(x);
% n3 e. k6 E9 e6 C* \printf("'e' raised to the power \ 5 j! v( W! ^$ i. }/ |2 H
of %lf (e ^ %lf) = %lf\n", 6 T E2 q+ o) }2 m8 z% t
x, x, result); 
* ^ w4 u7 y& y# Q6 _1 hreturn 0;
4 m* \; w% h$ l& Q4 D7 [}
9 R$ m* ]$ }/ }; s1 S% i

zan

转播0 淘帖0 分享0 收藏0 支持0 反对0 微信

使用道具举报

韩冰

823 主题	3 听众	4048 积分

我的地盘我做主

该用户从未签到

2^#

发表于 2004-10-4 03:02 |只看该作者 |招呼Ta 关注Ta

<

align=center>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 <DOS.H><

>int main(void)
{
sound(440);
delay(500);
nosound(); <

>return 0;
}

<

>函数名: delline 
功能: 在文本窗口中删去一行
用法: void delline(void);
程序例: <

>#include <CONIO.H><

>int main(void)
{
clrscr();
cprintf("The function DELLINE deletes \
the line containing the\r\n");
cprintf("cursor and moves all lines \
below it one line up.\r\n");
cprintf("DELLINE operates within the \
currently active text\r\n");
cprintf("window. Press any key to \
continue . . .");
gotoxy(1,2); /* Move the cursor to the
second line and first column */
getch(); <

>delline();
getch(); <

>return 0;
} 
<

>函数名: detectgraph 
功能: 通过检测硬件确定图形驱动程序和模式
用法: void far detectgraph(int far *graphdriver, int far *graphmode);
程序例: <

>#include <GRAPHICS.H>
#include <STDLIB.H>
#include <STDIO.H>
#include <CONIO.H><

>/* names of the various cards supported */
char *dname[] = { "requests detection",
"a CGA",
"an MCGA",
"an EGA",
"a 64K EGA",
"a monochrome EGA",
"an IBM 8514",
"a Hercules monochrome",
"an AT&T 6300 PC",
"a VGA",
"an IBM 3270 PC"
}; <

>int main(void)
{
/* returns detected hardware info. */
int gdriver, gmode, errorcode; <

>/* detect graphics hardware available */
detectgraph(&gdriver, &gmode); <

>/* read result of detectgraph call */
errorcode = graphresult();
if (errorcode != grOk) /* an error
occurred */
{
printf("Graphics error: %s\n", \
grapherrormsg(errorcode));
printf("

ress any key to halt:");
getch();
exit(1); /* terminate with an error
code */
} <

>/* display the information detected */
clrscr();
printf("You have %s video display \
card.\n", dname[gdriver]);
printf("

ress any key to halt:");
getch();
return 0;
} 

<

>函数名: difftime 
功能: 计算两个时刻之间的时间差
用法: double difftime(time_t time2, time_t time1);
程序例: <

>#include <TIME.H>
#include <STDIO.H>
#include <DOS.H>
#include <CONIO.H><

>int main(void)
{
time_t first, second; <

>clrscr();
first = time(NULL); /* Gets system
time */
delay(2000); /* Waits 2 secs */
second = time(NULL); /* Gets system time
again */ <

>printf("The difference is: %f \
seconds\n",difftime(second,first));
getch(); <

>return 0;
}

<

>函数名: disable 
功能: 屏蔽中断
用法: void disable(void);
程序例: <

>/***NOTE: This is an interrupt service
routine. You cannot compile this program
with Test Stack Overflow turned on and
get an executable file that operates
correctly. */ <

>#include <STDIO.H>
#include <DOS.H>
#include <CONIO.H><

>#define INTR 0X1C /* The clock tick
interrupt */ <

>void interrupt ( *oldhandler)(void); <

>int count=0; void interrupt handler(void)
{
/* disable interrupts during the handling of
the interrupt */
disable();
/* increase the global counter */
count++;
/* reenable interrupts at the end of the
handler */
enable();
/* call the old routine */
oldhandler();
} int main(void)
{
/* save the old interrupt vector */
oldhandler = getvect(INTR); /* install the new interrupt handler */
setvect(INTR, handler); /* loop until the counter exceeds 20 */
while (count < 20)
printf("count is %d\n",count); /* reset the old interrupt handler */
setvect(INTR, oldhandler); return 0;
} 函数名: div 
功能: 将两个整数相除, 返回商和余数
用法: div_t (int number, int denom);
程序例: #include <STDLIB.H>
#include <STDIO.H>div_t x; int main(void)
{
x = div(10,3);
printf("10 div 3 = %d remainder %d\n", x.quot, x.rem); return 0;
}

函数名: dosexterr 
功能: 获取扩展DOS错误信息
用法: int dosexterr(struct DOSERR *dblkp);
程序例: #include <STDIO.H>
#include <DOS.H>int main(void)
{
FILE *fp;
struct DOSERROR info; fp = fopen("perror.dat","r");
if (!fp) perror("Unable to open file for
reading");
dosexterr(&info); printf("Extended DOS error \
information:\n");
printf(" Extended error: \
%d\n",info.exterror);
printf(" Class: \
%x\n",info.class);
printf(" Action: \
%x\n",info.action);
printf(" Error Locus: \
%x\n",info.locus); return 0;
} 

函数名: dostounix 
功能: 转换日期和时间为UNIX时间格式
用法: long dostounix(struct date *dateptr, struct time *timeptr);
程序例: #include <TIME.H>
#include <STDDEF.H>
#include <DOS.H>
#include <STDIO.H>int main(void)
{
time_t t;
struct time d_time;
struct date d_date;
struct tm *local; getdate(&d_date);
gettime(&d_time); t = dostounix(&d_date, &d_time);
local = localtime(&t);
printf("Time and Date: %s\n", \
asctime(local)); return 0;
} 

函数名: drawpoly 
功能: 画多边形
用法: void far drawpoly(int numpoints, int far *polypoints);
程序例: #include <GRAPHICS.H>
#include <STDLIB.H>
#include <STDIO.H>
#include <CONIO.H>int main(void)
{
/* request auto detection */
int gdriver = DETECT, gmode, errorcode;
int maxx, maxy; /* our polygon array */
int poly[10]; /* initialize graphics and local
variables */
initgraph(&gdriver, &gmode, ""); /* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk)
/* an error occurred */
{
printf("Graphics error: %s\n", \
grapherrormsg(errorcode));
printf("Press any key to halt:");
getch();
/* terminate with an error code */
exit(1);
} maxx = getmaxx();
maxy = getmaxy(); poly[0] = 20; /* 1st vertext */
poly[1] = maxy / 2; poly[2] = maxx - 20; /* 2nd */
poly[3] = 20; poly[4] = maxx - 50; /* 3rd */
poly[5] = maxy - 20; poly[6] = maxx / 2; /* 4th */
poly[7] = maxy / 2;
/*
drawpoly doesn't automatically close
the polygon, so we close it.
*/
poly[8] = poly[0];
poly[9] = poly[1]; /* draw the polygon */
drawpoly(5, poly); /* clean up */
getch();
closegraph();
return 0;
}

函数名: dup 
功能: 复制一个文件句柄
用法: int dup(int handle);
程序例: #include <STRING.H>
#include <STDIO.H>
#include <CONIO.H>
#include <IO.H>void flush(FILE *stream); int main(void)
{
FILE *fp;
char msg[] = "This is a test"; /* create a file */
fp = fopen("DUMMY.FIL", "w"); /* write some data to the file */
fwrite(msg, strlen(msg), 1, fp); clrscr();
printf("Press any key to flush \
DUMMY.FIL:");
getch(); /* flush the data to DUMMY.FIL without
closing it */
flush(fp); printf("\nFile was flushed, Press any \
key to quit:");
getch();
return 0;
} void flush(FILE *stream)
{
int duphandle; /* flush TC's internal buffer */
fflush(stream); /* make a duplicate file handle */
duphandle = dup(fileno(stream)); /* close the duplicate handle to flush the
DOS buffer */
close(duphandle);
}

函数名: dup2 
功能: 复制文件句柄
用法: int dup2(int oldhandle, int newhandle);
程序例: #include <SYS\STAT.H>
#include <STRING.H>
#include <FCNTL.H>
#include <IO.H>int main(void)
{
#define STDOUT 1 int nul, oldstdout;
char msg[] = "This is a test"; /* create a file */
nul = open("DUMMY.FIL", O_CREAT | O_RDWR,
S_IREAD | S_IWRITE); /* create a duplicate handle for standard
output */
oldstdout = dup(STDOUT);
/*
redirect standard output to DUMMY.FIL
by duplicating the file handle onto the
file handle for standard output.
*/
dup2(nul, STDOUT); /* close the handle for DUMMY.FIL */
close(nul); /* will be redirected into DUMMY.FIL */
write(STDOUT, msg, strlen(msg)); /* restore original standard output
handle */
dup2(oldstdout, STDOUT); /* close duplicate handle for STDOUT */
close(oldstdout); return 0;
}