C语言中的read()和fgets()之间的区别 [英] Difference between read() and fgets() in C
问题描述
我想从stdin流中读取.使用read()或fgets()从stdin流中读取有什么区别.
I want to read from a stdin stream. Is there any difference in using read() or fgets() to read from the stdin stream.
我将以下两段代码与fgets附加在一起并阅读. 使用fgets,我可以使用Java程序轻松地从c程序中读写. 通过读写,我的java程序挂起,等待C程序的输出未出现.
I am attaching the following two pieces of code with fgets and read. With fgets I can use a java program to write and read from the c program easily. With read and write my java program hangs waiting for the output from C program which does not come.
我正在阅读一行,将其保留在buf中,并在其后附加A.
I am just reading a line keeping it in buf and appending A to it.
Java程序可以与下面的与fgets和puts一起使用的程序进行对话.
Java program is able to talk to the following program which works with fgets and puts.
#include <stdio.h>
#include <string.h>
#define SIZE 200000
main()
{
int rc;
int df;
int i;
char buf[SIZE];
for(i=0;i<=120000;i++) {
memset(buf,'\0',SIZE);
if(!fgets(buf,SIZE-1,stdin))
continue;
strcat(buf,"A_A_A_A_A_A_A");
puts(buf);
}
}
但不包含read()和write()
but not with read() and write()
main()
{
int rc;
int df;
int i;
char buf[32768];
rc = fcntl(fileno(stdin), F_SETFL, O_NONBLOCK);
//rc = fcntl(fileno(stdout), F_SETFL, O_NONBLOCK);
FILE *fp;
for (;;)
{
int rc=-1;
memset(buf,'\0',32768);
//rc = fread(buf,5, 1, stdin);
rc = read(fileno(stdin),buf,32768);
if (rc > 0)
{
strcat(buf,"B_B_B_B_B_B_B_B_B");
write(fileno(stdout),buf,strlen(buf));
}
}
}
有人可以说出原因.我仍然很难弄清
Could some one tell the reason. I am still finding it hard to figure out
推荐答案
-
fgets
是一个函数,read
是一个系统调用 -
fgets
是标准C,read
不是 -
fgets
是stdio缓冲的,read
不是 -
fgets
适用于FILE *
,read
适用于文件描述符 -
fgets
读取直到换行,read
读取告诉您的内容 fgets
is a function,read
is a system callfgets
is standard C,read
is notfgets
is stdio buffered,read
is notfgets
works with aFILE *
,read
works with a file descriptorfgets
reads until newline,read
reads how much you tell it to
需要更多吗?
这篇关于C语言中的read()和fgets()之间的区别的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!