c语言函数大全(f开头).txt

c语言的常用函数以及一些小游戏代码,如文曲星小游戏、五子棋游戏等

C语言函数大全(f开头)
来源 http://www.ddvip.net/program/c/index5/8.htm 
时间 2005-07-26 作者 unknow 

double fabs(double x); 

返回双精度x的绝对值。 


void far *farcalloc(unsigned long nunits,unsigned long unitsz); 

堆中给含有nu从远nits个元素的，每个元素占用unitsz个字节长的数组分配存贮区。 
成功是返回指向新分配的内存块的指针；若存贮空间不够，返回NULL。 

unsigned long farcoreleft(void); 

返回远堆中未用存贮区的大小。 


void farfree(void far *block); 

释放远堆中以前所分配内存块。 


void far *farmalloc(unsigned long nbytes); 

从远堆分配长nbytes字节的内存块，返回新地址。 
C语言函数大全(h开头)
函数名: harderr 
功 能: 建立一个硬件错误处理程序 
用 法: void harderr(int (*fptr)()); 
程序例: 
/*This program will trap disk errors and prompt 
the user for action. Try running it with no 
disk in drive A: to invoke its functions.*/ 

#include 
#include 
#include 
#define IGNORE 0 
#define RETRY 1 
#define ABORT 2 
int buf[500]; 
/*define the error messages for trapping disk problems*/ 
static char *err_msg[] = { 
"write protect", 
"unknown unit", 
"drive not ready", 
"unknown command", 
"data error (CRC)", 
"bad request", 
"seek error", 
"unknown media type", 
"sector not found", 
"printer out of paper", 
"write fault", 
"read fault", 
"general failure", 
"reserved", 
"reserved", 
"invalid disk change" 
}; 

error_win(char *msg) 
{ 
int retval; 

cputs(msg); 

/*prompt for user to press a key to abort, retry, ignore*/ 
while(1) 
{ 
retval= getch(); 
if (retval == 'a' || retval == 'A') 
{ 
retval = ABORT; 
break; 
} 
if (retval == 'r' || retval == 'R') 
{ 
retval = RETRY; 
break; 
} 
if (retval == 'i' || retval == 'I') 
{ 
retval = IGNORE; 
break; 
} 
} 

return(retval); 
} 

/*pragma warn -par reduces warnings which occur 
due to the non use of the parameters errval, 
bp and si to the handler.*/ 
#pragma warn -par 

int handler(int errval,int ax,int bp,int si) 
{ 
static char msg[80]; 
unsigned di; 
int drive; 
int errorno; 
di= _DI; 
/*if this is not a disk error then it was 
another device having trouble*/ 

if (ax < 0) 
{ 
/* report the error */ 
error_win("Device error"); 
/* and return to the program directly requesting abort */ 
hardretn(ABORT); 
} 
/* otherwise it was a disk error */ 
drive = ax & 0x00FF; 
errorno = di & 0x00FF; 
/* report which error it was */ 
sprintf(msg, "Error: %s on drive %c\r\nA)bort, R)etry, I)gnore: ", 
err_msg[errorno], 'A' + drive); 
/* 
return to the program via dos interrupt 0x23 with abort, retry, 
or ignore as input by the user. 
*/ 
hardresume(error_win(msg)); 
return ABORT; 
} 
#pragma warn +par 

int main(void) 
{ 
/* 
install our handler on the hardware problem interrupt 
*/ 
harderr(handler); 
clrscr(); 
printf("Make sure there is no disk in drive A:\n"); 
printf("Press any key ....\n"); 
getch(); 
printf("Trying to access drive A:\n"); 
printf("fopen returned %p\n",fopen("A:temp.dat", "w")); 
return 0; 
} 



函数名: hardresume 
功 能: 硬件错误处理函数 
用 法: void hardresume(int rescode); 
程序例: 


/* This program will trap disk errors and prompt the user for action. */ 
/* Try running it with no disk in drive A: to invoke its functions */ 

#include 
#include 
#include 

#define IGNORE 0 
#define RETRY 1 
#define ABORT 2 

int buf[500]; 

/* define the error messages for trapping disk problems */ 
static char *err_msg[] = { 
"write protect", 
"unknown unit", 
"drive not ready", 
"unknown command", 
"data error (CRC)", 
"bad request", 
"seek error", 
"unknown media type", 
"sector not found", 
"printer out of paper", 
"write fault", 
"read fault", 
"general failure", 
"reserved", 
"reserved", 
"invalid disk change" 
}; 

error_win(char *msg) 
{ 
int retval; 

cputs(msg); 

/* prompt for user to press a key to abort, retry, ignore */ 
while(1) 
{ 
retval= getch(); 
if (retval == 'a' || retval == 'A') 
{ 
retval = ABORT; 
break; 
} 
if (retval == 'r' || retval == 'R') 
{ 
retval = RETRY; 
break; 
} 
if (retval == 'i' || retval == 'I') 
{ 
retval = IGNORE; 
break; 
} 
} 

return(retval); 
} 

/* pragma warn -par reduces warnings which occur due to the non use */ 
/* of the parameters errval, bp and si to the handler. */ 
#pragma warn -par 

int handler(int errval,int ax,int bp,int si) 
{ 
static char msg[80]; 
unsigned di; 
int drive; 
int errorno; 

di= _DI; 
/* if this is not a disk error then it was another device having trouble */ 

if (ax < 0) 
{ 
/* report the error */ 
error_win("Device error"); 
/* and return to the program directly 
requesting abort */ 
hardretn(ABORT); 
} 
/* otherwise it was a disk error */ 
drive = ax & 0x00FF; 
errorno = di & 0x00FF; 
/* report which error it was */ 
sprintf(msg, "Error: %s on drive %c\r\nA)bort, R)etry, I)gnore: ", 
err_msg[errorno], 'A' + drive); 
/* return to the program via dos interrupt 0x23 with abort, retry */ 
/* or ignore as input by the user. */ 
hardresume(error_win(msg)); 
return ABORT; 
} 
#pragma warn +par 

int main(void) 
{ 
/* install our handler on the hardware problem interrupt */ 
harderr(handler); 
clrscr(); 
printf("Make sure there is no disk in drive A:\n"); 
printf("Press any key ....\n"); 
getch(); 
printf("Trying to access drive A:\n"); 
printf("fopen returned %p\n",fopen("A:temp.dat", "w")); 
return 0; 
} 



函数名: highvideo 
功 能: 选择高亮度文本字符 
用 法: void highvideo(void); 
程序例: 

#include 

int main(void) 
{ 
clrscr(); 

lowvideo(); 
cprintf("Low Intensity text\r\n"); 
highvideo(); 
gotoxy(1,2); 
cprintf("High Intensity Text\r\n"); 

return 0; 
} 



函数名: hypot 
功 能: 计算直角三角形的斜边长 
用 法: double hypot(double x, double y); 
程序例: 

#include 
#include 

int main(void) 
{ 
double result; 
double x = 3.0; 
double y = 4.0; 

result = hypot(x, y); 
printf("The hypotenuse is: %lf\n", result); 

return 0; 
}


void far *farrealloc(void far *oldblock,unsigned long nbytes); 

调整已分配的内存块的大小为nbytes。需要的话，可把块中的内容复制到新位置。要注意：所有的可用的RAM可被分配，大于64K的块可被分配。 
远指针用于存取被分配的块。返回重新分配的内存块的地址。若存贮块重新分配失败，返回NULL。 

struct fcb { 

char fcb_drive; /* 0 = default, 1 = A, 2 = B */ 

char fcb_name[8]; /* File name */ 

char fcb_ext[3]; /* File extension */ 

short fcb_curblk; /* Current block number */ 

short fcb_recsize; /* Logical record size in bytes */ 

long fcb_filsize; /* File size in bytes */ 

short fcb_date; /* Date file was last written */ 

char fcb_resv[10]; /* Reserved for DOS */ 

char fcb_currec; /* Current record in block */ 

long fcb_random; /* Random record number */ 

}; 

int fclose(FILE *stream); 

关闭一个流。 

成功返回0；失败是返回EOF。 

int fcloseall(void); 

关闭所有打开的流，除了stdin,stdout,stdprn,stderr和stdaux。 




char *fcvt(double value,int ndig,int *dec,int *sign); 

把浮点数转换成字符串，把浮点数value转换成长度为ndig的以空字符终结的字符串，返回一个指向这个字符串的指针，相对于串的开始处， 
小数点的位置，由dec间接存贮，dec若为负值，表示小数点在返回的字符串的左边。返回的字符串本身不带小数点。如果value的符号为负，由sign指向的值非零；否则它是零。 

FILE *fdopen(int handle,char *type); 

把流与一个文件描述字相联系地打开。fdopen使流stream与一个从creat,dup,dup2或open得到的文件描述字相联系。流的类型type必须与打开文件描述字handle的模式相匹配。 

类型字符串type可以是下列值之一： 

r,打开用于只读； 

w,创建用于写； 

a,打开用于写在原有内容后面，文件不存在时创建用于写； 

r+，打开已存在的文件用于更新（读和写）； 

a+，添加打开，文件不存在时创建，在末尾更新。成功时返回新打开的流。出错时返回NULL。 

int feof(FILE *stream); 

测试所给stream的文件尾标记的宏。 

若检测到文件尾标记EOF或Ctrl-z返回非零值；否则，返回0。 


#include 

int ferror(FILE *stream); 

测试给定流读写错误的宏。 

若检测到给定流上的错误返回非0值。 

struct ffblk { 

char ff_reserved[21]; 

char ff_attrib; 

unsigned ff_ftime; 

unsigned ff_fdate; 

long ff_fsize; 

char ff_name[13]; 

}; 




int fflush(FILE *stream); 

清除输入流的缓冲区，使它仍然打开，并把输出流的缓冲区的内容写入它所联系的文件中。成功时返回0，出错时返回EOF。 

int fgetc(FILE *stream); 

从流中读取下一个字符。 

成功是返回输入流中的下一个字符；至文件结束或出错时返回EOF。 


int fgetchar(void); 

从标准输入流中读取字符，时定义为getc(stdin)的宏。 
返回输入流stdin中的下一个字符，它已被转换成为无符号扩展的整形值。遇到出错或文件结束时返回EOF。 

int fgetpos(FILE stream,fpos_t *pos);