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Turbo C 2.0、Borland C++库函数及用例(32) 功 能: 送一个字符到标准输出流(stdout)中
用 法: int fputchar(char ch);
程序例:#include <stdio.h>int main(void)
{
char msg[] = "This is a test";
int i = 0;
while (msg[i])
{
fputchar(msg[i]); i++;
}
return 0;
}
函数名: fputs
功 能: 送一个字符到一个流中
用 法: int fputs(char *string, FILE *stream);
程序例:#include <stdio.h>
int main(void)
{
/* write a string to standard output */
fputs("Hello world\n", stdout);
return 0;
}
函数名: fread
功 能: 从一个流中读数据
用 法: int fread( void *ptr, int size, int nitems,
FILE *stream );
程序例:#include <string.h>
#include <stdio.h>int main(void)
{
FILE *stream;
char msg[] = "this is a test";
char buf[20]; if ((stream = fopen("DUMMY.FIL", "w+"))
== NULL)
{
fprintf(stderr,
"Cannot open output file.\n");
return 1;
}
/* write some data to the file */
fwrite(msg, strlen(msg)+1, 1, stream); /* seek to the beginning of the file */
fseek(stream, SEEK_SET, 0); /* read the data and display it */
fread(buf, strlen(msg)+1, 1, stream);
printf("%s\n", buf); fclose(stream);
return 0;
}
函数名: free
功 能: 释放已分配的块
用 法: void free(void *ptr);
程序例:#include <string.h>
#include <stdio.h>
#include <alloc.h>int main(void)
{
char *str; /* allocate memory for string */
str = malloc(10); /* copy "Hello" to string */
strcpy(str, "Hello"); /* display string */
printf("String is %s\n", str); /* free memory */
free(str); return 0;
}
函数名: freemem
功 能: 释放先前分配的DOS内存块
用 法: int freemem(unsigned seg);
程序例:#include <dos.h>
#include <alloc.h>
#include <stdio.h>int main(void)
{
unsigned int size, segp;
int stat; size = 64; /* (64 x 16) = 1024 bytes */
stat = allocmem(size, &segp);
if (stat < 0)
printf("Allocated memory at segment:\
%x\n", segp);
else
printf("Failed: maximum number of\
paragraphs available is %u\n",
stat);
freemem(segp); return 0;
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