pty

Lets say I have one terminal where the output of "tty" is "/dev/pts/2" From another terminal, I want to send a command to the first terminal and execute it. Using: echo "ls" > "/dev/pts/2" only prints "ls" in the first terminal Is there a way to execute the string? No; terminals don't execute commands. They're just channels for data. You can sort of run a command and attach it to another terminal like this, though: ls </dev/pts/2 >/dev/pts/2 2>/dev/pts/2 It won't behave exactly like you ran it from that terminal, though, as it won't have that device set as its controlling terminal. It's

If I start a terminal, how do I know what mode it starts in? Who decides that? Can I start my terminal in packet mode i.e. TIOCPKT I came across this Packet mode link which says: Packet mode is enabled by pushing the pckt module on the master-side. - I do not understand this exactly. The link you refer to is for SCO Unix, which has the STREAMS I/O subsystem. There is a pretty good overview of STREAMS here (its for Solaris, but same concepts apply to other *nixes). The manual page tells you that you have to push the pckt module onto the stream, which is done with an ioctl() call with the I_PUSH

I am programming something that needs an interface to Bash. At first I thought I could just use popen or QProcess. ( I'm using QT C++ ) They work fine but I can't get them to run Bash in a tty, which you need if you are going to use anything like sudo, which requires a tty/pty to accept a password. I found some things like forkpty(), openpty(), etc. in the GNU Standard C libraries, but could not figure out how to use them or find any good examples, even after reading their corresponding manpages. Literally, all this part of my program needs to do is be able to read/write from a tty running

From time to time I'm getting an OSError exception with the message 'out of pty devices' when calling pty.openpty() (it's happening when a bunch of instances of my scripts run concurrently). What is the limit that I'm hitting? How can I get around this? CentOS 5.6, Python 2.4 In my Ubuntu Linux, the max number of open ptys is given by: cat /proc/sys/kernel/pty/max This value is configurable in: /etc/sysctl.conf All this info, and much more can be found in: man pty Same issue is raised when devpts is not mounted, usually in chroots, to mount devpts device type: # mount -t devpts none /path/to

I'd like to redirect jshell input using expect, so that I can simulate typing in recorded demonstrations. But although I can spawn a jshell process from an expect script, which can also recognise the jshell prompt, after that nothing works. expect outputs what looks like a control sequence, like ^[[24;9R , and I don't see any output from jshell. Different terminal types produce different character sequences, but none of them work. This behaviour is consistent between expect on Ubuntu and Mac OS. Any suggestions for how to investigate this problem would be welcome. expect -d doesn't help. Here

The slave fd is used by another application (say "A") as a serial port device . A will set its baud rate/stop bit etc. My app needs this information . BTW, is there any way for a process that has only the master fd open to be notified of all ioctl() calls that are issued to the slave fd ? Yes, this is possible (in Linux and pre-2004 FreeBSD) , using the pty in packet mode and setting the EXTPROC flag on it. Packet mode is enabled on the master end by ioctl(master, TIOCPKT, &nonzero) . Now every read on the master end will yield a packet : whatever was written on the other side, plus a status