Piped sockets under tcl

[Ofloo]

How do I create a named pipe instead of creating a socket to listen on. I've been searching google, looking through the manual, but I can't find anything about named pipes.

[rosc2112]

Read about pipelines in the manpage for open:
http://www.tcl.tk/man/tcl8.4/TclCmd/open.htm

[Ofloo]

As far as I know is what you're suggesting only for execution.

Code: Select all

open "|/path/to/binary" r+

not to make named pipes (sockets)

such as /tmp/mysql.sock, for example, or would you be so kind explain yourself, ..

[nml375]

Been a while since I played around with named pipes, but as I recall you create them with 'mknod' or 'mkfifo' and then just use them as regular files:

Example using two concurrent shell-sessions:
Session 1

Code: Select all

bash$ mknod /home/myhome/test.fifo
bash$ ls -l > /home/myhome/test.fifo

Session 2

Code: Select all

bash$ cat /home/myhome/test.fifo
-rwxr--r--   1 nml375 nml375    16896 26 maj  2006 network.doc
-rw-rw-r--   1 nml375 nml375     1927 11 okt  2005 private-root-pem.crt
...

Should'nt be much different with tcl..

Or where you thinking of unix sockets?

[Ofloo]

i was thinking of making a script listen on a unix socket.
like:

Code: Select all

socket -server myproc localhost 1234

[nml375]

As far as I know, there is no support for unix sockets in tcl.
Also, keep in mind that "named pipes" is something completely different from "unix sockets", where the first one uses simple file I/O for communications while the second makes use of the kernels support for socket communication, with the domain AF_UNIX rather than AF_INET (which is used for IP sockets).

I suppose IP sockets won't cut it for you?

If you really want unix sockets, you'd have to create some wrapping-code to provide the function calls from the socket-library to the tcl-environment (possibly by creating an eggdrop module).
One option, I guess, would be to write your project entirely as a module rather than a tcl-script.

[Sir_Fz]

Perhaps user's code would help: socket api - nonblocking tcp made easy.

[Ofloo]

I know how to use sockets, it's just that i want a to create a unix socket.

ok it's

Code: Select all

socket -server myproc -myaddr 127.0.0.1 1234

So I assume it's not possible.

i think maybe mknod might do..

[nml375]

Keep in mind that named pipes are "one-way connections", that is, one client must open the fifo in readonly mode, and other client in writeonly mode.

Btw, if you wanted to work with unix socket, why were you asking for named pipes?

[Ofloo]

I asked for a named pipe which functioned as a socket, UNIX sockets I suppose.

i want to be able to '|' pipe data from syslogd to a script.

but since reading from stdin is having some issues.. i wanted to use pipes instead.

[nml375]

Pipes and sockets (IP/IPX/Unix/etc all alike) are two completely different concepts, hence there is no "named pipe with socket functions" (unix or otherwize).
Pipes are used just like any other file-stream, whereas sockets have a far more complex structure.

As for your intent to send data from syslogd; a quick check in the manual page would reveal that syslogd allows files, ip/udp, and named pipes to be destination for logmessages. It does not, however, support unix sockets as destination.