C语言的函数!

内财数模协会 · 发表于 2004-5-10 16:30:36

<

>函数名: randbwr
功能: 随机块写
用法: int randbwr(struct fcp *fcbptr, int reccnt);
程序例: <

>#include <process.h>
#include <string.h>
#include <stdio.h>
#include <dos.h> <

>int main(void)
{
char far *save_dta;
char line[80];
char buffer[256] = "RANDBWR test!";
struct fcb blk;
int result; /* get new file name from user */
printf("Enter a file name to create (no path - ie. a:file.dat\n");
gets(line); /* parse the new file name to the dta */
parsfnm(line,&blk,1);
printf("Drive #%d File: %s\n", blk.fcb_drive, blk.fcb_name); /* request DOS services to create file */
if (bdosptr(0x16, &blk, 0) == -1)
{
 perror("Error creating file");
 exit(1);
} /* save old dta and set new dta */
save_dta = getdta();
setdta(buffer); /* write new records */
blk.fcb_recsize = 256;
blk.fcb_random = 0L;
result = randbwr(&blk, 1); if (!result)
 printf("Write OK\n");
else
{
 perror("Disk error");
 exit(1);
} /* request DOS services to close the file */
if (bdosptr(0x10, &blk, 0) == -1)
{
 perror("Error closing file");
 exit(1);
} /* reset the old dta */
setdta(save_dta); return 0;
}

内财数模协会 · 发表于 2004-5-10 16:30:46

<

>函数名: random
功能: 随机数发生器
用法: int random(int num);
程序例: <

>#include <stdlib.h>
#include <stdio.h>
#include <time.h> <

>/* prints a random number in the range 0 to 99 */
int main(void)
{
randomize();
printf("Random number in the 0-99 range: %d\n", random (100));
return 0;
}

内财数模协会 · 发表于 2004-5-10 16:30:55

<

>函数名: randomize
功能: 初始化随机数发生器
用法: void randomize(void);
程序例: <

>#include <stdlib.h>
#include <stdio.h>
#include <time.h> <

>int main(void)
{
int i; randomize();
printf("Ten random numbers from 0 to 99\n\n");
for(i=0; i<10; i++)
printf("%d\n", rand() % 100);
return 0;
}

内财数模协会 · 发表于 2004-5-10 16:31:06

<

>函数名: read
功能: 从文件中读
用法: int read(int handle, void *buf, int nbyte);
程序例: <

>#include <stdio.h>
#include <io.h>
#include <alloc.h>
#include <fcntl.h>
#include <process.h>
#include <sys\stat.h> <

>int main(void)
{
void *buf;
int handle, bytes; buf = malloc(10); /*
Looks for a file in the current directory named TEST.$$$ and attempts
to read 10 bytes from it. To use this example you should create the
file TEST.$$$
*/
if ((handle =
 open("TEST.$$$", O_RDONLY | O_BINARY, S_IWRITE | S_IREAD)) == -1)
{
 printf("Error Opening File\n");
 exit(1);
} if ((bytes = read(handle, buf, 10)) == -1) {
 printf("Read Failed.\n");
 exit(1);
}
else {
 printf("Read: %d bytes read.\n", bytes);
}
return 0;
}

内财数模协会 · 发表于 2004-5-10 16:31:16

<

>函数名: realloc
功能: 重新分配主存
用法: void *realloc(void *ptr, unsigned newsize);
程序例: <

>#include <stdio.h>
#include <alloc.h>
#include <string.h> <

>int main(void)
{
char *str; /* allocate memory for string */
str = malloc(10); /* copy "Hello" into string */
strcpy(str, "Hello"); printf("String is %s\n Address is %p\n", str, str);
str = realloc(str, 20);
printf("String is %s\n New address is %p\n", str, str); /* free memory */
free(str); return 0;
}

内财数模协会 · 发表于 2004-5-10 16:31:27

<

>函数名: rectangle
功能: 画一个矩形
用法: void far rectangle(int left, int top, int right, int bottom);
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 left, top, right, bottom; /* 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();
 exit(1); /* terminate with an error code */
} left = getmaxx() / 2 - 50;
top = getmaxy() / 2 - 50;
right = getmaxx() / 2 + 50;
bottom = getmaxy() / 2 + 50; /* draw a rectangle */
rectangle(left,top,right,bottom); /* clean up */
getch();
closegraph();
return 0;
}

内财数模协会 · 发表于 2004-5-10 16:32:00

<

>函数名: registerbgidriver
功能: 登录已连接进来的图形驱动程序代码
用法: int registerbgidriver(void(*driver)(void));
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; /* register a driver that was added into graphics.lib */
errorcode = registerbgidriver(EGAVGA_driver); /* report any registration errors */
if (errorcode < 0)
{
 printf("Graphics error: %s\n", grapherrormsg(errorcode));
 printf("Press any key to halt:");
 getch();
 exit(1); /* terminate with an error code */
} /* 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();
 exit(1); /* terminate with an error code */
} /* draw a line */
line(0, 0, getmaxx(), getmaxy()); /* clean up */
getch();
closegraph();
return 0;
}

内财数模协会 · 发表于 2004-5-10 16:32:10

<

>函数名: remove
功能: 删除一个文件
用法: int remove(char *filename);
程序例: <

>#include <stdio.h> <

>int main(void)
{
char file[80]; /* prompt for file name to delete */
printf("File to delete: ");
gets(file); /* delete the file */
if (remove(file) == 0)
 printf("Removed %s.\n",file);
else
 perror("remove"); return 0;
}

内财数模协会 · 发表于 2004-5-10 16:32:21

<

>函数名: rename
功能: 重命名文件
用法: int rename(char *oldname, char *newname);
程序例: <

>#include <stdio.h> <

>int main(void)
{
char oldname[80], newname[80]; /* prompt for file to rename and new name */
printf("File to rename: ");
gets(oldname);
printf("New name: ");
gets(newname); /* Rename the file */
if (rename(oldname, newname) == 0)
printf("Renamed %s to %s.\n", oldname, newname);
else
perror("rename"); return 0;
}

内财数模协会 · 发表于 2004-5-10 16:32:34

<

>函数名: restorecrtmode
功能: 将屏幕模式恢复为先前的imitgraph设置
用法: void far restorecrtmode(void);
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 x, y; /* 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();
 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 any key to exit graphics:");
getch(); /* restore system to text mode */
restorecrtmode();
printf("We're now in text mode.\n");
printf("Press any key to return to graphics mode:");
getch(); /* return to graphics mode */
setgraphmode(getgraphmode()); /* output a message */
settextjustify(CENTER_TEXT, CENTER_TEXT);
outtextxy(x, y, "We're back in graphics mode.");
outtextxy(x, y+textheight("W"), "Press any key to halt:"); /* clean up */
getch();
closegraph();
return 0;
}

		自动登录	找回密码
密码			注-册-帐-号