01-25-2011
Certain things like ssh (and many other authentication systems) don't use stdin/stdout/stderr but directly open the controlling terminal, often /dev/tty (which on linux at least is kind of 'magic' in that /dev/tty is always your own terminal, no matter what that may be.) This happens after the shell runs the program, and can't be redirected.
You'd need to create your own virtual terminal device to intercept traffic at this level. The virtual terminal would be the controlling terminal and ssh would open and interact with it. This is how the expect language is able to interact with programs that demand a terminal device.
10 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
hi everybody,
when i run and compile this:
printf("test"); fflush(stdout);
nothing appears on screen.
if i try this:
___________________________________
printf("test"); fflush(stdout); sleep(10);
___________________________________
then i can see the output "test"... for 10... (4 Replies)
Discussion started by: brain_processin
4 Replies
2. AIX
Hi,
I see from lsvg the total used PPs is 1050 (67200 megabytes), but when I check the disk space with df command I can only see 31G total space, can somebody tell how this come?
Thanks!
Victor
# lsvg
rootvg
# lsvg rootvg
VOLUME GROUP: rootvg VG IDENTIFIER: ... (2 Replies)
Discussion started by: victorcheung
2 Replies
3. Shell Programming and Scripting
Is it possible to store all standard-out of a bash script and the binaries it calls in a log file AND still display the stdout on screen?
I know this is possible to store ALL stdout/stderr of a script to a single log file like:
exec 1>&${logFile}
exec 2>&1
But running a script with the... (3 Replies)
Discussion started by: ckmehta
3 Replies
4. Shell Programming and Scripting
Dear Member,
OLD Question --> disable-completion not solved
My bash Menu script ping process problem.
If ping still running and users press SCREEN is Blank...
Cant Members help me.. kill signal or others scripting for my case, btw i use Linux..
Thanks,
Rico
My Bash Script :
... (1 Reply)
Discussion started by: carnegiex
1 Replies
5. Shell Programming and Scripting
I am unable to use clear or cls command on bash shell. I have recently installed Cygwin and am using that for practicing unix commands.
I see that I can use Ctrl + L to clear the screen. I created an alias in my .bashrc to do the same as
alias cls='^L'
This is how i defined other aliases ... (4 Replies)
Discussion started by: erora
4 Replies
6. Shell Programming and Scripting
Hi all,
How to:
Run a bash script, display on the screen and save all information in a file including error information.
For example:
I have a bash script called test.sh
now I want to run the test.sh and display the output on the screen and save the output including error info to a file.
... (1 Reply)
Discussion started by: Damon sine
1 Replies
7. Programming
the error occurs in the function() "add" used...
#include<stdio.h>
#include<malloc.h>
struct node
{
int exp;
int coef;
struct node * link;
};
struct node * create_list(struct node *,int,int);
void display(struct node *);
struct node * add(struct node *,struct node *);
... (3 Replies)
Discussion started by: mscoder
3 Replies
8. Red Hat
Hi,
I have a simple question : how to disable screen lock and/or sreen saver with command line with RHEL5.4 ? (1 Reply)
Discussion started by: albator1932
1 Replies
9. UNIX for Dummies Questions & Answers
The block size in my home directory is showed wrong when I use "quota" command. It shows I use 1.2 gb ( about 1200000) while the real size in my directory which I use "du" command is 96 MB
I really confused. (0 Replies)
Discussion started by: thsecmaniac
0 Replies
10. UNIX for Beginners Questions & Answers
Hello, everyone. I'm currently trying to write a command system for a Minecraft server using screen.
Here are the scripts I'm currently using.
0.sh
#!/bin/bash
screen -S Test114 -dm java -Xmx4G -jar server.jar nogui
1.sh
#!/bin/bash
args="$@"
args2="${args@Q}"
#args3=`printf '%q\n'... (2 Replies)
Discussion started by: Develon
2 Replies
PTY(4) BSD Kernel Interfaces Manual PTY(4)
NAME
pty -- BSD-style compatibility pseudo-terminal driver
SYNOPSIS
device pty
DESCRIPTION
The pty driver provides support for the traditional BSD naming scheme that was used for accessing pseudo-terminals. When the device
/dev/ptyXX is being opened, a new terminal shall be created with the pts(4) driver. A device node for this terminal shall be created, which
has the name /dev/ttyXX.
New code should not try to allocate pseudo-terminals using this interface. It is only provided for compatibility with older C libraries that
tried to open such devices when posix_openpt(2) was being called.
FILES
The BSD-style compatibility pseudo-terminal driver uses the following device names:
/dev/pty[l-sL-S][0-9a-v] Pseudo-terminal master devices.
/dev/tty[l-sL-S][0-9a-v] Pseudo-terminal slave devices.
DIAGNOSTICS
None.
SEE ALSO
posix_openpt(2), pts(4), tty(4)
HISTORY
A pseudo-terminal driver appeared in 4.2BSD.
BUGS
Unlike previous implementations, the master slave device nodes are destroyed when the PTY becomes unused. A call to stat(2) on a nonexistent
master device will already cause a new master device node to be created. The master device can only be destroyed by opening and closing it.
The pty driver cannot be unloaded, because it cannot determine if it is being used.
BSD
August 20, 2008 BSD