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Turbo C 2.0、Borland C++库函数及用例(25) fopen("DUMMY.TWO", "w"); /* close the open streams */
streams_closed = fcloseall(); if (streams_closed == EOF)
/* issue an error message */
perror("Error");
else
/* print result of fcloseall() function */
printf("%d streams were closed.\n", streams_closed); return 0;
}
函数名: fcvt
功 能: 把一个浮点数转换为字符串
用 法: char *fcvt( double value, int ndigit, int *decpt,
int *sign );
程序例:#include <stdlib.h>
#include <stdio.h>
#include <conio.h>int main(void)
{
char *string;
double value; int dec, sign;
int ndig = 10; clrscr();
value = 9.876;
string = ecvt(value, ndig, &dec, &sign);
printf("string = %s dec = %d \
sign = %d\n", string, dec, sign);
value = -123.45;
ndig= 15;
string = ecvt(value,ndig,&dec,&sign);
printf("string = %s dec = %d sign = %d\n",
string, dec, sign); value = 0.6789e5; /* scientific
notation */
ndig = 5;
string = ecvt(value,ndig,&dec,&sign);
printf("string = %s dec = %d\
sign = %d\n", string, dec, sign);
return 0;
}
函数名: fdopen
功 能: 把流与一个文件句柄相接
用 法: FILE *fdopen(int handle, char *type);
程序例:#include <sys\stat.h>
#include <stdio.h>
#include <fcntl.h>
#include <io.h>int main(void)
{
int handle;
FILE *stream; /* open a file */
handle = open("DUMMY.FIL", O_CREAT,
S_IREAD S_IWRITE);
/* now turn the handle into a stream */
stream = fdopen(handle, "w"); if (stream == NULL)
printf("fdopen failed\n");
else
{
fprintf(stream, "Hello world\n");
fclose(stream);
} return 0;
}
函数名: feof
功 能: 检测流上的文件结束符
用 法: int feof(FILE *stream);
程序例:#include <stdio.h>int main(void)
{
FILE *stream; /* open a file for reading */
stream = fopen("DUMMY.FIL", "r"); /* read a character from the file */
fgetc(stream); /* check for EOF */
if (feof(stream))
printf("We have reached end-of-file\n"); /* close the file */
fclose(stream);
return 0;
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