文档介绍：函数名: abort
功能: 异常终止一个进程
用法: void abort(void);
程序例:
#include <>
#include <>
int main(void)
{
printf("Calling abort()\n");
abort();
return 0; /* This is never reached */
}
函数名: abs
功能: 求整数的绝对值
用法: int abs(int i);
程序例:
#include <>
#include <>
int main(void)
{
int number = -1234;
printf("number: %d absolute value: %d\n", number, abs(number));
return 0;
}
函数名: absread, abswirte
功能: 绝对磁盘扇区读、写数据
用法: int absread(int drive, int nsects, int sectno, void *buffer);
int abswrite(int drive, int nsects, in tsectno, void *buffer);
程序例:
/* absread example */
#include <>
#include <>
#include <>
#include <>
int main(void)
{
int i, strt, ch_out, sector;
char buf[512];
printf("Insert a diskette into drive A and press any key\n");
getch();
sector = 0;
if (absread(0, 1, sector, &buf) != 0)
{
perror("Disk problem");
exit(1);
}
printf("Read OK\n");
strt = 3;
for (i=0; i<80; i++)
{
ch_out = buf[strt+i];
putchar(ch_out);
}
printf("\n");
return(0);
}
函数名: access
功能: 确定文件的访问权限
用法: int access(const char *filename, int amode);
程序例:
#include <>
#include <>
int file_exists(char *filename);
int main(void)
{
printf("Does exist: %s\n",
file_exists("") "YES" : "NO");
return 0;
}
int file_exists(char *filename)
{
return (access(filename, 0) == 0);
}
函数名: acos
功能: 反余弦函数
用法: double acos(double x);
程序例:
#include <>
#include <>
int main(void)
{
double result;
double x = ;
result = acos(x);
printf("The arc cosine of %lf is %lf\n", x, result);
return 0;
}
函数名: allocmem
功能: 分配DOS存储段
用法: int allocmem(unsigned size, unsigned *seg);
程序例:
#include <>
#include <>
#include <>
int main(void)
{
unsigned int size, segp;
int stat;
size = 64; /* (64 x 16) = 10