10-04-2016
Quote:
Originally Posted by
Juha Nurmela
I had a peek into the expect, and it does look like there would a mechanism to run the children in a pty, to reduce line-buffering.
Some programs are smart enough to turn off buffering when talking to a terminal or pipe but
nothing forces them to. Its a choice the program makes - "I am talking to a terminal, therefore, turn off the internal buffer". It's not something chosen from the outside. It's not even anything system at all. It's a choice between calling write() once, to write blocks of several thousand bytes at a time, or calling write() many times, one for each line. It's a difference in a program's logic.
In short, still entirely up to the program and can't be forced from the outside by any means if the program doesn't already support it somehow.
10 More Discussions You Might Find Interesting
1. Programming
I have a project where I have to use bzcat to uncompress a file and use that output as the data to run another program on.
I understand that you would do (bzcat filename.bz2 ! program name) but then how do you access that data in the c program??? Please help thanks (2 Replies)
Discussion started by: kinggizmo
2 Replies
2. Windows & DOS: Issues & Discussions
Hello!
Will someone out there pls help in clearifying what is really wrong with my system. I use window 98 as my operating system. I am connected to a proxy server for browsing the net. Whenever l am listening to music online l have the problem of intermitted break in which the playing will... (10 Replies)
Discussion started by: kayode
10 Replies
3. Programming
Hi,
Program A: uses pipe()
I am able to read the stdout of PROGAM B (stdout got through system() command) into PROGRAM A using:
* child
-> dup2(fd, STDOUT_FILENO);
-> execl("/path/PROGRAM B", "PROGRAM B", NULL);
* parent
-> char line;
-> read(fd, line, 100);
Question:... (2 Replies)
Discussion started by: vvaidyan
2 Replies
4. Shell Programming and Scripting
Using ls input as example..
ls | sed 's/\n/ /'outputs with line breaks, where I was expecting the \n to disappear. I've tried \r as well wondering if terminal output used different breaks.
Is there a way to remove the line breaks without saving to file and then working from there?
----------... (2 Replies)
Discussion started by: davidpbrown
2 Replies
5. Shell Programming and Scripting
I have an Shell script which has few global variables
eg :
range=100;
echo "$range"
I want to use the same variable in my C++ program for example
int main()
{ cout << range << "\n"; }
i tried using this
int main(int argc, char *argv)
{ cout << range << "\n"; }
but... (5 Replies)
Discussion started by: shashi792
5 Replies
6. Shell Programming and Scripting
Can anyone tell me why does'nt the following command work?
find /gfp1/home/arijit -name "*.sas7bdat" | gzip
I am trying to compress all files with extension sas7bdat with gzip.
It gives error message
gzip: compressed data not written to a terminal. Use -f to force compression.... (5 Replies)
Discussion started by: bs0409
5 Replies
7. Programming
Hi,
I have 1 program that writes in to the STDIN of another program as shown below. Both programs contain 4 or 5 lines & would terminate in under a second.
$ driver.exe | program.exe
How is that I can attach the debugger (gdb) to program.exe ? so that I can step through and see what all... (0 Replies)
Discussion started by: RipClaw
0 Replies
8. Shell Programming and Scripting
Hi
I am new to writing script and want to use a Bash Piped while-read and read from user input.
if something happens on server.log then do while loop or if something happend on user input then do while loop.
Pseudocode something like:
tail -n 3 -f server.log | while read serverline || read... (8 Replies)
Discussion started by: MyMorris
8 Replies
9. Shell Programming and Scripting
Hi,
Here is my question:
I want a shell script which I name as 'del', and can be used as del(string).
when run del(string), it will delete several directories at different locations in my system,like:
rm -fr /lustre/fs/scratch/user/$string
rm -fr /home/user/$string
rm -fr... (4 Replies)
Discussion started by: 1988PF
4 Replies
10. Shell Programming and Scripting
Suppose I have a program that I've written that accepts input, ie this C++ program:
#include <iostream>
using namespace std;
int main()
{
cout << "Enter something:" << endl;
int x;
cin >> x;
cout << "You entered data" << endl;
}
Suppose that I have a text file,... (5 Replies)
Discussion started by: Chris J
5 Replies
WRITE(1) BSD General Commands Manual WRITE(1)
NAME
write -- send a message to another user
SYNOPSIS
write user [ttyname]
DESCRIPTION
The write utility allows you to communicate with other users, by copying lines from your terminal to theirs.
When you run the write command, the user you are writing to gets a message of the form:
Message from yourname@yourhost on yourtty at hh:mm ...
Any further lines you enter will be copied to the specified user's terminal. If the other user wants to reply, they must run write as well.
When you are done, type an end-of-file or interrupt character. The other user will see the message 'EOF' indicating that the conversation is
over.
You can prevent people (other than the super-user) from writing to you with the mesg(1) command.
If the user you want to write to is logged in on more than one terminal, you can specify which terminal to write to by specifying the termi-
nal name as the second operand to the write command. Alternatively, you can let write select one of the terminals - it will pick the one
with the shortest idle time. This is so that if the user is logged in at work and also dialed up from home, the message will go to the right
place.
The traditional protocol for writing to someone is that the string '-o', either at the end of a line or on a line by itself, means that it's
the other person's turn to talk. The string 'oo' means that the person believes the conversation to be over.
SEE ALSO
mesg(1), talk(1), wall(1), who(1)
HISTORY
A write command appeared in Version 1 AT&T UNIX.
BSD
June 6, 1993 BSD