Checking to see that the stream pointer is NULL/not NULL is okay.
What happens in the case that stdin is redirected, which is, I think, what you may want.
try something like this:
Your best bet is to refer to Steven's "Advanced Programming in the UNIX Environment"
Hi,
When it proccesing the backup with cpio report this message: Cannot open "/dev/tty" and cancel de backup.
Cuando se procesa la tarea del backup reporta el error: Cannot open "/dev/tty" y cancela el backup y no termina correctamente, a que se devera esta advertencia.
Gracias.
Thacks.... (3 Replies)
Hi...
This is message that occurs when i am trying to shutdown the linux system
timeout opening writing control channel /dev/initctl
how can i shutdown what is the problem here..
Thanks in advance
... (2 Replies)
Hi, Anyone can help
My solaris 8 system has the following
/dev/null , /dev/tty and /dev/console
All permission are lrwxrwxrwx
Can this be change to a non-world write ??
any impact ?? (12 Replies)
hello all,
Being root, I would like to log user activity (also multiple root activity), i don't really like
history file based logging, lets assume that users have access to their .profile.
I would like to write a monitoring daemon in C that would capture /dev/ttys,
so I need to do a... (0 Replies)
Hi,
I need to provide more than one character to "> /dev/tty" through terminal/keyboard input, I have this:
ok=false
while
do
echo " Enter r1 to reformat "
> /dev/tty
read choice
case $choice in
)
echo " bla bla bla "
;;
done
However, in this way,... (3 Replies)
Hello everybody:
I have a child process which reads a password from /dev/tty, as far as I know file descriptors for the child process can be seen by using lsof, so I want to connect to such device in order to send the password through a pipe, how could I do that? (2 Replies)
hi,
From the below script:
##########################################pwd_auth.sh########################################################################################
#Author: Pandeeswaran Bhoopathy
#Written on:26th Jan 2012 2:00PM
#This script describes the feature of stty and illustrates... (3 Replies)
Hello,
One one of my AIX boxes I'm having the following errror:
fcstat fcs0:
Port Speed (supported): 4 GBIT
Error opening device: /dev/fscsi0
errno: 0000003d
Has anyone encountered similar errors?
Thank you! (1 Reply)
Suppose another person wrote the following one-line shell script:
echo $RANDOM > /dev/tty
QUESTION #1: How can the random number, which is output to the terminal by this script, be captured in a variable?
QUESTION #2: How can this be done in a cron job?
Specific code, whether in ksh or... (1 Reply)
Discussion started by: Paul R
1 Replies
LEARN ABOUT DEBIAN
stderr
FD(4) BSD Kernel Interfaces Manual FD(4)NAME
fd, stdin, stdout, stderr -- file descriptor files
DESCRIPTION
The files /dev/fd/0 through /dev/fd/# refer to file descriptors which can be accessed through the file system. If the file descriptor is
open and the mode the file is being opened with is a subset of the mode of the existing descriptor, the call:
fd = open("/dev/fd/0", mode);
and the call:
fd = fcntl(0, F_DUPFD, 0);
are equivalent.
Opening the files /dev/stdin, /dev/stdout and /dev/stderr is equivalent to the following calls:
fd = fcntl(STDIN_FILENO, F_DUPFD, 0);
fd = fcntl(STDOUT_FILENO, F_DUPFD, 0);
fd = fcntl(STDERR_FILENO, F_DUPFD, 0);
Flags to the open(2) call other than O_RDONLY, O_WRONLY and O_RDWR are ignored.
IMPLEMENTATION NOTES
By default, /dev/fd is provided by devfs(5), which provides nodes for the first three file descriptors. Some sites may require nodes for
additional file descriptors; these can be made available by mounting fdescfs(5) on /dev/fd.
FILES
/dev/fd/#
/dev/stdin
/dev/stdout
/dev/stderr
SEE ALSO tty(4), devfs(5), fdescfs(5)BSD June 9, 1993 BSD