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函数大全(e开头)

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韩冰

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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); 8 c- h! L! l; H% T% a1 D
printf("About to exec child with arg1 arg2 ...\n"); $ H" D+ L; W0 R0 k; w# k
execv("CHILD.EXE", argv); - D& J1 }* g: a: H$ p% Y! j
perror("exec error"); - B4 |* W( }8 m4 j6 S
exit(1); - F0 ]6 h6 q3 s: n6 v" e) Q2 C
}
7 `2 i; [0 W8 M e' Z6 o+ f& y+ g+ o* n" r" l5 l
( {! n: |) Q6 r4 a- I# k T
函数名: exit - A, [$ D0 b/ D+ ~: P
功能: 终止程序
& w8 V/ ~# F) b8 X5 d" K0 x- T& L& I用法: void exit(int status);
8 O T2 R# M }) ]+ @7 k) F程序例: 
+ ]4 Q; j+ j# j1 m9 @) Y1 @' i#include <STDLIB.H>% `- s4 b0 Q6 {% R2 z- a
#include <CONIO.H> b8 g I5 y( q w5 @* j
#include <STDIO.H>
% g9 |6 E7 X6 K7 B# F6 Y% lint main(void) 6 @& y y* }1 K, e! B5 t6 q
{
7 v0 d6 M0 |2 C4 Wint status; 
- z1 B4 u0 Q \( m9 r$ Wprintf("Enter either 1 or 2\n"); " y$ |1 E% l+ @- f$ B+ ?2 {5 @
status = getch();
/ w9 L2 G- |" \! D3 r/* Sets DOS errorlevel */
2 b2 e0 K7 |: f' Z; x! M1 _4 Oexit(status - '0'); 
! _! U$ w: P1 |- t2 h2 C l/* Note: this line is never reached */
3 Y, g, r' t3 B3 ~+ s$ d# ~0 Preturn 0; 2 p. f0 N9 L- H8 a4 I; [+ G
}
- z* T2 r9 d, Q) f3 I1 V' M# v6 `( f6 C. w" G1 i* {8 a1 ^. }

% L: l2 |0 Y" I2 V: r- E函数名: exp 7 g% `) t/ ]+ q6 v4 |- L
功能: 指数函数 3 E1 q( r# `4 K
用法: double exp(double x);
) u! s( N( U# S程序例: ) k& R) T4 X7 s. R" k5 I ~* q
#include <STDIO.H>7 C& x% g+ v/ ?5 n6 e
#include <MATH.H>
+ l E9 N1 o1 K# w8 Vint main(void) % u( H! D/ |* ] v9 U6 f$ v6 o
{
" z8 D6 L' O" _3 r; H7 kdouble result;
5 G5 b; G4 B! Z2 q% E- Idouble x = 4.0; 
6 u r4 x9 m* C1 | Lresult = exp(x); # t9 Y# s& s e) @
printf("'e' raised to the power \
4 D8 L9 L- s! S+ u, X8 vof %lf (e ^ %lf) = %lf\n", 0 [$ i3 U: k0 D( d* A4 W3 W A
x, x, result); 2 G- Q8 {' |, H' V
return 0; % g) h6 ^! L6 f6 A
}2 H' ~( h$ m0 [% A" u( ]' L- y" i! r/ t

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韩冰

823 主题	3 听众	4048 积分

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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;
}