c语言函数大全

墙角野猫

函数名: putimage
功 能: 在屏幕上输出一个位图
用 法: void far putimage(int x, int y, void far *bitmap, int op);
程序例:
#include
#include
#include
#include
#define ARROW_SIZE 10
void draw_arrow(int x, int y);
int main(void)
{
/* request autodetection */
int gdriver = DETECT, gmode, errorcode;
void *arrow;
int x, y, maxx;
unsigned int size;
/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");
/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk) /* an error occurred */
{
printf("Graphics error: %s
", grapherrormsg(errorcode));
printf("Press any key to halt:");
getch();
exit(1); /* terminate with an error code */
}
maxx = getmaxx();
x = 0;
y = getmaxy() / 2;
/* draw the image to be grabbed */
draw_arrow(x, y);
/* calculate the size of the image */
size = imagesize(x, y-ARROW_SIZE, x+(4*ARROW_SIZE), y+ARROW_SIZE);
/* allocate memory to hold the image */
arrow = malloc(size);
/* grab the image */
getimage(x, y-ARROW_SIZE, x+(4*ARROW_SIZE), y+ARROW_SIZE, arrow);
/* repeat until a key is pressed */
while (!kbhit())
{
/* erase old image */
putimage(x, y-ARROW_SIZE, arrow, XOR_PUT);
x += ARROW_SIZE;
if (x >= maxx)
x = 0;
/* plot new image */
putimage(x, y-ARROW_SIZE, arrow, XOR_PUT);
}
/* clean up */
free(arrow);
closegraph();
return 0;
}
void draw_arrow(int x, int y)
{
/* draw an arrow on the screen */
moveto(x, y);
linerel(4*ARROW_SIZE, 0);
linerel(-2*ARROW_SIZE, -1*ARROW_SIZE);
linerel(0, 2*ARROW_SIZE);
linerel(2*ARROW_SIZE, -1*ARROW_SIZE);
}

墙角野猫

函数名: putpixel
功 能: 在指定位置画一像素
用 法: void far putpixel (int x, int y, int pixelcolor);
程序例:
#include
#include
#include
#include
#include
#define PIXEL_COUNT 1000
#define DELAY_TIME 100 /* in milliseconds */
int main(void)
{
/* request autodetection */
int gdriver = DETECT, gmode, errorcode;
int i, x, y, color, maxx, maxy, maxcolor, seed;
/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");
/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk) /* an error occurred */
{
printf("Graphics error: %s
", grapherrormsg(errorcode));
printf("Press any key to halt:");
getch();
exit(1); /* terminate with an error code */
}
maxx = getmaxx() + 1;
maxy = getmaxy() + 1;
maxcolor = getmaxcolor() + 1;
while (!kbhit())
{
/* seed the random number generator */
seed = random(32767);
srand(seed);
for (i=0; i {
x = random(maxx);
y = random(maxy);
color = random(maxcolor);
putpixel(x, y, color);
}
delay(DELAY_TIME);
srand(seed);
for (i=0; i {
x = random(maxx);
y = random(maxy);
color = random(maxcolor);
if (color == getpixel(x, y))
putpixel(x, y, 0);
}
}
/* clean up */
getch();
closegraph();
return 0;
}

墙角野猫

函数名: puts
功 能: 送一字符串到流中
用 法: int puts(char *string);
程序例:
#include
int main(void)
{
char string[] = "This is an example output string
";
puts(string);
return 0;
}

墙角野猫

函数名: puttext
功 能: 将文本从存储区拷贝到屏幕
用 法: int puttext(int left, int top, int right, int bottom, void *source);
程序例:
#include
int main(void)
{
char buffer[512];
/* put some text to the console */
clrscr();
gotoxy(20, 12);
cprintf("This is a test. Press any key to continue ...");
getch();
/* grab screen contents */
gettext(20, 12, 36, 21,buffer);
clrscr();
/* put selected characters back to the screen */
gotoxy(20, 12);
puttext(20, 12, 36, 21, buffer);
getch();
return 0;
}

墙角野猫

函数名: putw
功 能: 把一字符或字送到流中
用 法: int putw(int w, FILE *stream);
程序例:
#include
#include
#define FNAME "test.$$$"
int main(void)
{
FILE *fp;
int word;
/* place the word in a file */
fp = fopen(FNAME, "wb");
if (fp == NULL)
{
printf("Error opening file %s
", FNAME);
exit(1);
}
word = 94;
putw(word,fp);
if (ferror(fp))
printf("Error writing to file
");
else
printf("Successful write
");
fclose(fp);
/* reopen the file */
fp = fopen(FNAME, "rb");
if (fp == NULL)
{
printf("Error opening file %s
", FNAME);
exit(1);
}
/* extract the word */
word = getw(fp);
if (ferror(fp))
printf("Error reading file
");
else
printf("Successful read: word = %d
", word);
/* clean up */
fclose(fp);
unlink(FNAME);
return 0;
}

墙角野猫

函数名: qsort
功 能: 使用快速排序例程进行排序
用 法: void qsort(void *base, int nelem, int width, int (*fcmp)());
程序例:
#include
#include
#include
int sort_function( const void *a, const void *b);
char list[5][4] = { "cat", "car", "cab", "cap", "can" };

int main(void)
{
int x;
qsort((void *)list, 5, sizeof(list[0]), sort_function);
for (x = 0; x < 5; x++)
printf("%s
", list[x]);
return 0;
}
int sort_function( const void *a, const void *b)
{
return( strcmp(a,b) );
}

墙角野猫

函数名: qsort
功 能: 使用快速排序例程进行排序
用 法: void qsort(void *base, int nelem, int width, int (*fcmp)());
程序例:
#include
#include
#include
int sort_function( const void *a, const void *b);
char list[5][4] = { "cat", "car", "cab", "cap", "can" };

int main(void)
{
int x;
qsort((void *)list, 5, sizeof(list[0]), sort_function);
for (x = 0; x < 5; x++)
printf("%s
", list[x]);
return 0;
}
int sort_function( const void *a, const void *b)
{
return( strcmp(a,b) );
}

墙角野猫

函数名: raise
功 能: 向正在执行的程序发送一个信号
用 法: int raise(int sig);
程序例:
#include
int main(void)
{
int a, b;
a = 10;
b = 0;
if (b == 0)
/* preempt divide by zero error */
raise(SIGFPE);
a = a / b;
return 0;
}

墙角野猫

函数名: rand
功 能: 随机数发生器
用 法: void rand(void);
程序例:
#include
#include
int main(void)
{
int i;
printf("Ten random numbers from 0 to 99
");
for(i=0; i<10; i++)
printf("%d
", rand() % 100);
return 0;
}

墙角野猫

函数名: randbrd
功 能: 随机块读
用 法: int randbrd(struct fcb *fcbptr, int reccnt);
程序例:
#include
#include
#include
#include
int main(void)
{
char far *save_dta;
char line[80], buffer[256];
struct fcb blk;
int i, result;
/* get user input file name for dta */
printf("Enter drive and file name (no path - i.e. a:file.dat)
");
gets(line);
/* put file name in fcb */
if (!parsfnm(line, &blk, 1))
{
printf("Error in call to parsfnm
");
exit(1);
}
printf("Drive #%d File: %s
", blk.fcb_drive, blk.fcb_name);
/* open file with DOS FCB open file */
bdosptr(0x0F, &blk, 0);
/* save old dta, and set new one */
save_dta = getdta();
setdta(buffer);
/* set up info for the new dta */
blk.fcb_recsize = 128;
blk.fcb_random = 0L;
result = randbrd(&blk, 1);
/* check results from randbrd */
if (!result)
printf("Read OK
");
else
{
perror("Error during read");
exit(1);
}
/* read in data from the new dta */
printf("The first 128 characters are:
");
for (i=0; i<128; i++)
putchar(buffer);
/* restore previous dta */
setdta(save_dta);
return 0;
}