函数名: sbrk
功 能: 改变数据段空间位置
用 法: char *sbrk(int incr);
程序例:
#include <stdio.h>
#include <alloc.h>
int main(void)
{
printf("Changing allocation with sbrk()\n");
printf("Before sbrk() call: %lu bytes free\n",
(unsigned long) coreleft());
sbrk(1000);
printf(" After sbrk() call: %lu bytes free\n",
(unsigned long) coreleft());
return 0;
}
函数名: scanf
功 能: 执行格式化输入
用 法: int scanf(char *format[,argument,...]);
程序例:
#include <stdio.h>
#include <conio.h>
int main(void)
{
char label[20];
char name[20];
int entries = 0;
int loop, age;
double salary;
struct Entry_struct
{
char name[20];
int age;
float salary;
} entry[20];
/* Input a label as a string of characters restricting to 20 characters */
printf("\n\nPlease enter a label for the chart: ");
scanf("%20s", label);
fflush(stdin); /* flush the input stream in case of bad input */
/* Input number of entries as an integer */
printf("How many entries will there be? (less than 20) ");
scanf("%d", &entries);
fflush(stdin); /* flush the input stream in case of bad input */
/* input a name restricting input to only letters upper or lower case */
for (loop=0;loop<entries;++loop)
{
printf("Entry %d\n", loop);
printf(" Name : ");
scanf("%[A-Za-z]", entry[loop].name);
fflush(stdin); /* flush the input stream in case of bad input */
/* input an age as an integer */
printf(" Age : ");
scanf("%d", &entry[loop].age);
fflush(stdin); /* flush the input stream in case of bad input */
/* input a salary as a float */
printf(" Salary : ");
scanf("%f", &entry[loop].salary);
fflush(stdin); /* flush the input stream in case of bad input */
}
/* Input a name, age and salary as a string, integer, and double */
printf("\nPlease enter your name, age and salary\n");
scanf("%20s %d %lf", name, &age, &salary);
/* Print out the data that was input */
printf("\n\nTable %s\n",label);
printf("Compiled by %s age %d $%15.2lf\n", name, age, salary);
printf("-----------------------------------------------------\n");
for (loop=0;loop<entries;++loop)
printf("%4d | %-20s | %5d | %15.2lf\n",
loop + 1,
entry[loop].name,
entry[loop].age,
entry[loop].salary);
printf("-----------------------------------------------------\n");
return 0;
}
函数名: searchpath
功 能: 搜索DOS路径
用 法: char *searchpath(char *filename);
程序例:
#include <stdio.h>
#include <dir.h>
int main(void)
{
char *p;
/* Looks for TLINK and returns a pointer
to the path */
p = searchpath("TLINK.EXE");
printf("Search for TLINK.EXE : %s\n", p);
/* Looks for non-existent file */
p = searchpath("NOTEXIST.FIL");
printf("Search for NOTEXIST.FIL : %s\n", p);
return 0;
}
函数名: sector
功 能: 画并填充椭圆扇区
用 法: void far sector(int x, int y, int stangle, int endangle);
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, i;
int stangle = 45, endangle = 135;
int xrad = 100, yrad = 50;
/* 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 */
}
midx = getmaxx() / 2;
midy = getmaxy() / 2;
/* loop through the fill patterns */
for (i=EMPTY_FILL; i<USER_FILL; i++)
{
/* set the fill style */
setfillstyle(i, getmaxcolor());
/* draw the sector slice */
sector(midx, midy, stangle, endangle, xrad, yrad);
getch();
}
/* clean up */
closegraph();
return 0;
}
函数名: segread
功 能: 读段寄存器值
用 法: void segread(struct SREGS *segtbl);
程序例:
#include <stdio.h>
#include <dos.h>
int main(void)
{
struct SREGS segs;
segread(&segs);
printf("Current segment register settings\n\n");
printf("CS: %X DS: %X\n", segs.cs, segs.ds);
printf("ES: %X SS: %X\n", segs.es, segs.ss);
return 0;
}
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