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Turbo C 2.0、Borland C++库函数及用例(23) double x = 4.0; result = exp(x); printf("'e' raised to the power \
of %lf (e ^ %lf) = %lf\n",
x, x, result); return 0;
}字母Ｆ开头函数函数名: fabs
功 能: 返回浮点数的绝对值
用 法: double fabs(double x);
程序例:#include <stdio.h>
#include <math.h>
int main(void)
{
float number = -1234.0;
printf("number: %f absolute value: %f\n",
number, fabs(number));
return 0;
}
函数名: farcalloc
功 能: 从远堆栈中申请空间
用 法: void far *farcalloc( unsigned long units,
unsigned ling unitsz );
程序例:
#include <stdio.h>
#include <alloc.h>
#include <string.h>
#include <dos.h>int main(void)
{
char far *fptr;
char *str = "Hello"; /* allocate memory for the far pointer */
fptr = farcalloc(10, sizeof(char)); /* copy "Hello" into allocated memory */ /*
Note: movedata is used because you
might be in a small data model, in
which case a normal string copy routine
can not be used since it assumes the
pointer size is near. */
movedata(FP_SEG(str), FP_OFF(str),
FP_SEG(fptr), FP_OFF(fptr),
strlen(str)); /* display string (note the F modifier) */
printf("Far string is: %Fs\n", fptr); /* free the memory */
farfree(fptr); return 0;
}
函数名: farcoreleft
功 能: 返回远堆中未作用存储区大小
用 法: long farcoreleft(void);
程序例:#include <stdio.h>
#include <alloc.h>int main(void)
{
printf("The difference between the\
highest allocated block in the\
far\n"); printf("heap and the top of the far heap\
is: %lu bytes\n", farcoreleft()); return 0;
}
函数名: farfree
功 能: 从远堆中释放一块
用 法: void farfree(void);
程序例:#include <stdio.h>
#include <alloc.h>
#include <string.h>
#include <dos.h>int main(void)
{
char far *fptr;
char *str = "Hello"; /* allocate memory for the far pointer */
fptr = farcalloc(10, sizeof(char)); /* copy "Hello" into allocated memory */
/*
Note: movedata is used because you might be in a
small data model, in which case a normal string
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