Since the existence of /dev/tty is not guaranteed, what happens when an attempt is made to open /dev/tty and there's no controlling terminal?
Will it fail, or open /dev/null instead? Or do something else?
So is checking for NULL in the code below a safe way of checking whether opening /dev/tty was sucessful? If not how should it be checked?
Many thanks all.
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 NETBSD
mount_fdesc
MOUNT_FDESC(8) BSD System Manager's Manual MOUNT_FDESC(8)NAME
mount_fdesc -- mount the file-descriptor file system
SYNOPSIS
mount_fdesc [-o options] fdesc mount_point
DESCRIPTION
The mount_fdesc command attaches an instance of the per-process file descriptor namespace to the global filesystem namespace. The conven-
tional mount point is /dev and the filesystem should be union mounted in order to augment, rather than replace, the existing entries in /dev.
The directory specified by mount_point is converted to an absolute path before use.
This command is normally executed by mount(8) at boot time.
The options are as follows:
-o Options are specified with a -o flag followed by a comma separated string of options. See the mount(8) man page for possible options
and their meanings.
The contents of the mount point are fd, stderr, stdin, stdout and tty.
fd is a directory whose contents appear as a list of numbered files which correspond to the open files of the process reading the directory.
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.
The files /dev/stdin, /dev/stdout and /dev/stderr appear as symlinks to the relevant entry in the /dev/fd sub-directory. Opening them 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.
The /dev/tty entry is an indirect reference to the current process's controlling terminal. It appears as a named pipe (FIFO) but behaves in
exactly the same way as the real controlling terminal device.
FILES
/dev/fd/#
/dev/stdin
/dev/stdout
/dev/stderr
/dev/tty
SEE ALSO mount(2), unmount(2), tty(4), fstab(5), mount(8)HISTORY
The mount_fdesc utility first appeared in 4.4BSD.
BUGS
This filesystem may not be NFS-exported.
BSD March 27, 1994 BSD