Problem reading/writing sockets

8 Message(s) by 3 Author(s) originally posted in php programming

From: Can2002

Date: Wednesday, October 24, 2007

I have been trying to put together an app

<programming, operating system> (Or "application", "app") A
	complete, self-contained program that performs a specific
	function directly for the user.  This is in contrast to system
	software such as the {operating system} {kernel}, {server}
	processes and libraries which exists to support application
	programs.

	Editors for various kinds of documents, {spreadsheets}, and
	text formatters are common examples of applications.  Network
	applications include clients such as those for {FTP},
	{electronic mail}, {telnet} and {WWW}.

	The term is used fairly loosely, for instance, some might say
	that a client and server together form a distributed
	application, others might argue that editors and compilers
	were not applications but tools for building applications.

	One distinction between an application program and the
	operating system is that applications always run in "user
	mode" (or "non-privileged mode"), while operating systems and
	related utilities may run in "supervisor mode" (or "privileged
	mode").

	The term may also be used to distinguish programs which
	communicate via a {graphical user interface} from those which
	are executed from the {command line}.

	(1994-11-28)

lication to change channel

<chat> (Or "chat room", "room", depending on the system in
	question) The basic unit of group discussion in {chat} systems
	like {IRC}.  Once one joins a channel, everything one types is
	read by others on that channel.  Channels can either be named
	with numbers or with strings that begin with a "#" sign and
	can have topic descriptions (which are generally irrelevant to
	the actual subject of discussion).

	Some notable channels are "#initgame", "#hottub" and
	"#report".  At times of international crisis, "#report" has
	hundreds of members, some of whom take turns listening to
	various news services and typing in summaries of the news, or
	in some cases, giving first-hand accounts of the action
	(e.g. Scud missile attacks in Tel Aviv during the Gulf War in
	1991).

	[{Jargon File}]

	(1998-01-25)

on a
media streaming

<communications> Playing {sound} or {video} in {real time} as
	it is downloaded over the {Internet} as opposed to storing it
	in a local file first.  A {plug-in} to a {web browser} such as
	{Netscape Navigator} decompresses and plays the data as it is
	transferred to your computer over the {World-Wide Web}.
	Streaming audio or video avoids the delay entailed in
	downloading an entire file and then playing it with a {helper
	application}.  Streaming requires a fast connection and a
	computer powerful enough to execute the decompression
	{algorithm} in {real time}.

	(1996-11-06)

server

1. A program which provides some service to other ({client})
	programs.  The connection between client and server is
	normally by means of {message passing}, often over a
	{network}, and uses some {protocol} to encode the client's
	requests and the server's responses.  The server may run
	continuously (as a {daemon}), waiting for requests to arrive
	or it may be invoked by some higher level daemon which
	controls a number of specific servers ({inetd} on {Unix}).

	There are many servers associated with the {Internet}, such as
	those for {HTTP}, {Network File System}, {Network Information
	Service} (NIS), {Domain Name System} (DNS), {FTP}, {news},
	{finger}, {Network Time Protocol}.  On Unix, a long list can
	be found in /etc/services or in the {NIS} database "services".
	See {client-server}.

	2. A computer which provides some service for other computers
	connected to it via a network.  The most common example is a
	{file server} which has a local disk and services requests
	from remote clients to read and write files on that disk,
	often using {Sun}'s {Network File System} (NFS) {protocol} or
	{Novell Netware} on {PCs}.  Another common example is a {web
	server}.

	[{Jargon File}]

	(2003-12-29)

. The server is able to issue IR commands to
its attached equipment using LIRC, with commands being issued by a
socket

<networking> The {Berkeley Unix} mechansim for creating a
	virtual connection between processes.  Sockets interface
	{Unix}'s {standard I/O} with its {network} communication
	facilities.  They can be of two types, stream (bi-directional)
	or {datagram} (fixed length destination-addressed messages).
	The socket library function socket() creates a communications
	end-point or socket and returns a {file descriptor} with which
	to access that socket.  The socket has associated with it a
	socket address, consisting of a {port} number and the local
	host's network address.

	{Unix manual page}: socket(2).

	(1995-01-31)

connection to TCP/8765.

I put together a basic Python

1. <language> A simple, high-level interpreted language by
	Guido van Rossum <guido@cwi.nl>, 1991.  Python combines ideas
	from {ABC}, {C}, {Modula-3} and {Icon}.  It bridges the gap
	between {C} and {shell} programming, making it suitable for
	rapid prototyping or as an extension language for C
	applications.  It is {object-oriented} and supports packages,
	{modules}, {classes}, user-defined exceptions, a good C
	interface, dynamic loading of C modules and has no arbitrary
	restrictions.

	Python is available, among others, for {Unix}, {Windows},
	{DOS}, {OS/2}, {Macintosh}, and {Amoeba}.

	Current version: 1.4, includes {interpreter}, libraries, and
	documentation.

	{Home (http://www.python.org/)}.

	{Usenet} newsgroup: {news:comp.lang.python}.

	2. <compiler> A {compiler} for {CMU Common LISP}.  Python is
	more sophisticated than other {Common Lisp} compilers.  It
	produces better code and is easier to use.  The programming
	environment based on the {Hemlock} editor is better integrated
	than {GNU} {Emacs} based environments.

	(1997-02-27)

app that issued a command, which worked
fine. I wanted to create a fairly simple web interface

<jargon> A boundary across which two systems communicate.  An
	interface might be a hardware connector used to link to other
	devices, or it might be a convention used to allow
	communication between two software systems.  Often there is
	some intermediate component between the two systems which
	connects their interfaces together.  For example, two {EIA-232}
	interfaces connected via a serial cable.

	See also {graphical user interface}, {Application Program
	Interface}.

	(1996-05-22)

and so set
about producing a similar simple PHP application. I have had limited
success so far, with the media server rejecting the connections.
Unfortunately I have limited access to the OS of the media server - I
just know that it recognises the commands from the Python app and
rejects the PHP one. I need to submit the following string

<programming> A sequence of {data} values, usually {bytes},
	which usually stand for {characters} (a "character string").
	The {mapping} between values and characters is determined by
	the {character set} which is itself specified implcitly or
	explicitly by the environment in which the string is being
	interpreted.

	The most common character set is {ASCII} but, since the late
	1990s, there has been increased interest in larger character
	sets such as {Unicode} where each character is represented by
	more than eight {bits}.

	Most programming languages consider strings (e.g.
	"124:shabooya:\n", "hello world") basically distinct from
	numbers which are typically stored in fixed-length {binary} or
	{floating-point} representation.

	A {bit string} is a sequence of {bits}.

	(1999-12-21)

:

SEND_ONCE pace_stb_5 rm_power

My PHP app (with all error

1. A discrepancy between a computed, observed, or measured
	value or condition and the true, specified, or theoretically
	correct value or condition.

	2. <programming> A mental mistake made by a programmer that
	may result in a program {fault}.

	3. (verb) What a program does when it stops as result of a
	programming error.

	(2000-03-28)

checking removed) is as follows:

<?php
error_reporting(E_ALL);
echo

1. A {topic group} on {FidoNet}'s {echomail} system.

	Compare {newsgroup}.

	2. A {Unix} command that just prints its arguments.

	[{Jargon File}]

"<h2>TCP/IP Connection</h2>\n";
$service_port

1. <networking> A logical channel or channel endpoint in a
	communications system.  The {Transmission Control Protocol}
	and {User Datagram Protocol} {transport layer} protocols used
	on {Ethernet} use port numbers to distinguish between
	(demultiplex) different logical channels on the same {network
	interface} on a computer.

	Each {application program} has a unique port number associated
	with it, defined in /etc/services or the {Network Information
	Service} "services" database.  Some {protocols}, e.g. {telnet}
	and {HTTP} (which is actually a special form of telnet) have
	default ports specified as above but can use other ports as
	well.

	Some port numbers are defined in {RFC 3232} (which replaces
	RFC 1700).  Ports are now divided into: "Well Known" or
	"Privileged", and "Ephemeral" or "Unprivileged" (comprising
	"Registered", "Dynamic", "Private").

	(2004-12-30)

	2. <operating system, programming> To translate or modify
	{software} to run on a different {platform}, or the results of
	doing so.  The {portability} of the software determines how
	easy it is to port.

	3. <language> An {imperative} language descended from {Zed}
	from {Waterloo Microsystems} (now {Hayes} Canada) ca. 1979.

	["Port Language" document in the Waterloo Port Development
	System].

	(2002-06-19)

= '8765';
$address = '192.168.1.100';
$socket = socket_create(AF_INET, SOCK_STREAM, 0);
$result = socket_connect($socket, $address, $service_port);
$out = '';

socket_send($socket, 'SEND_ONCE pace_stb_5 rm_power\n',
strlen('SEND_ONCE pace_stb_5 rm_power\n'));
echo $result . "OK<br />";

$out = socket_read($socket, 1024);
echo $out;

socket_close($socket);
?>

In case it's of use, my Python application is:

#!/usr/bin/python
import

<data> To read data that is not in the native format of the
	application.  For example, a {web browser} will have its own
	way of storing {bookmarks} but it will usually provide a
	function to import bookmarks from {Internet Explorer}.  The
	alternative is to provide an independent external conversion
	utility but this is usually less convenient for the user.

	(2004-11-15)

socket,string

def send_ir(host

1. <networking> A computer connected to a {network}.

	The term {node} includes devices such as routers and printers
	which would not normally be called "hosts".

	2. <communications> A computer to which one connects using a
	{terminal emulator}.

	(1995-02-16)

, port, command):

exterity=socket.socket(socket.AF_INET,socket.SOCK_STREAM)
exterity.connect((host, port))
exterity.send(command+"\n")

while 1:
response = exterity.recv(1024)
if response.split('\n')[-2] == "END":
return response.split('\n')[1]
break
exterity-socket.close()

HOST = '192.168.1.100'
PORT = 8765

status = send_ir(HOST, PORT, 'SEND_ONCE pace_stb_5 rm_power')
print status

On the face of it it seems as though both apps are sending the same
string; however I'm wondering if they're submitting the strings in a
different way. Apologies if any of the above is vague; I will happily
provide any additional information if needed!

Thanks in advance,
Chris

From: Jerry Stuckle

Date: Wednesday, October 24, 2007

wrote in message:

I've been trying to put together an application to change channel on a
media streaming server. The server is able to issue IR commands to
its attached equipment using LIRC, with commands being issued by a
socket connection to TCP/8765.
I put together a basic Python app that issued a command, which worked
fine. I wanted to create a fairly simple web interface and so set
about producing a similar simple PHP application. I have had limited
success so far, with the media server rejecting the connections.
Unfortunately I have limited access to the OS of the media server - I
just know that it recognises the commands from the Python app and
rejects the PHP one. I need to submit the following string:
SEND_ONCE pace_stb_5 rm_power
My PHP app (with all error checking removed) is as follows:
<?php
error_reporting(E_ALL);
echo "<h2>TCP/IP Connection</h2>\n";
$service_port = '8765';
$address = '192.168.1.100';
$socket = socket_create(AF_INET, SOCK_STREAM, 0);
$result = socket_connect($socket, $address, $service_port);
$out = '';
socket_send($socket, 'SEND_ONCE pace_stb_5 rm_power\n',
strlen('SEND_ONCE pace_stb_5 rm_power\n'));
echo $result . "OK<br />";
$out = socket_read($socket, 1024);
echo $out;
socket_close($socket);
?>
In case it's of use, my Python application is:
#!/usr/bin/python
import socket,string
def send_ir(host, port, command):
exterity=socket.socket(socket.AF_INET,socket.SOCK_STREAM)
exterity.connect((host, port))
exterity.send(command+"\n")
while 1:
response = exterity.recv(1024)
if response.split('\n')[-2] == "END":
return response.split('\n')[1]
break
exterity-socket.close()
HOST = '192.168.1.100'
PORT = 8765
status = send_ir(HOST, PORT, 'SEND_ONCE pace_stb_5 rm_power')
print status
On the face of it it seems as though both apps are sending the same
string; however I'm wondering if they're submitting the strings in a
different way. Apologies if any of the above is vague; I will happily
provide any additional information if needed!
Thanks in advance,
Chris

socket_send($socket, 'SEND_ONCE pace_stb_5 rm_power\n',

You've the string in single quotes, so PHP sends the character

<character> An {atom} in a {character repertoire}.

	Compare with {glyph}.

	(1998-10-18)

s
backslash

<character> "\" {ASCII} code 92.  Common names: escape (from
	C/Unix); reverse slash; slosh; backslant; backwhack.  Rare:
	bash; {ITU-T}: reverse slant; reversed virgule; {INTERCAL}:
	backslat.

	Backslash is used to separate components in {MS-DOS}
	{pathnames}, and to introduce special character sequence in
	{C} and {Unix} strings, e.g. "\n" for newline.

	(2000-02-21)

and en, instead of the newline

<character, jargon> /n[y]oo'li:n/ {Line feed} or other
	character sequence used to terminate a line of text.

	{Unix} uses {line feed} as its text line terminator - a
	{Bell-Labs}-ism rather than a {Berkeley}ism.  Interestingly
	(and unusually for Unix jargon), it is said to have originally
	been an {IBM} usage.  Though the term "newline" appears in
	{ASCII} {standards}, it never caught on in the general
	computing world before {Unix}.  The encoding of line feed as
	"\n" in {C} and {Unix} strings comes from this name.

	The term has been used more generally for any {end of line}
	character, character sequence (e.g. {crlf}), or operation
	(like {Pascal}'s writeln procedure or {Lisp 1.5}'s {terpri})
	required to terminate a text record or separate lines.

	[{Jargon File}]

	(1997-07-14)

character you want.

Try pulling the string in double quotes (in both places).

--
==================
Remove the "x" from my email address
Jerry Stuckle
JDS Computer

<computer> A machine that can be programmed to manipulate
	symbols.  Computers can perform complex and repetitive
	procedures quickly, precisely and reliably and can quickly
	store and retrieve large amounts of data.

	The physical components from which a computer is constructed
	(electronic circuits and input/output devices) are known as
	"{hardware}".  Most computers have four types of hardware
	component: CPU, input, output and memory.  The CPU ({central
	processing unit}) executes programs ("{software}") which tell
	the computer what to do.  Input and output (I/O) devices allow
	the computer to communicate with the user and the outside
	world.  There are several kinds of memory - fast, expensive,
	short term memory (e.g. {RAM}) to hold intermediate results,
	and slower, cheaper, long-term memory (e.g. {magnetic disk} and
	{magnetic tape}) to hold programs and data between jobs.

	See also {analogue computer}.

	(1995-03-10)

Training Corp.
jstucklex@xxxxxxxxxxx
==================

From: Can2002

Date: Wednesday, October 24, 2007

wrote in message:

You have the string in single quotes, so PHP sends the characters
backslash and en, instead of the newline character you want.
Try pulling the string in double quotes (in both places).
--
==================
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
jstuck...@xxxxxxxxxxx
==================

Hi Jerry,

Thanks for coming back to me. I had originally used double quotes,
but the PHP script seemd to hand (firefox just reported waiting for
server for many minutes). I was obviously have a bad 5 mins, as when
I re-read the section on single vs. double quotes I could work out
why...

I will do some more experimentation.

Chris

From: Can2002

Date: Thursday, October 25, 2007

wrote in message:

but the PHP script seemd to hand

Oops, should've been hang

1. To wait for an event that will never occur.  "The system is
	hanging because it can't read from the crashed drive".  See
	{wedged}, {hung}.

	2. To wait for some event to occur; to hang around until
	something happens.  "The program displays a menu and then
	hangs until you type a character."  Compare {block}.

	3. To attach a peripheral device, especially in the
	construction "hang off": "We're going to hang another tape
	drive off the file server."  Implies a device attached with
	cables, rather than something that is strictly inside the
	machine's chassis.

, not hand!

Chris

From: Andrew DeFaria

Date: Thursday, October 25, 2007

--------------070105050708040502040109

wrote in message:
wrote in message:
but the PHP script seemd to hand
Oops, should've been hang, not hand!
Chris

But that "seemd" is just dandy!

My lord what are we teaching the kids now a days!
--
Andrew DeFaria <http://defaria.com>
I know you may think you know what I said, but I'm not sure that you
realize that what you think I said isn't really what I meant.--------------070105050708040502040109

--------------070105050708040502040109--

From: Jerry Stuckle

Date: Thursday, October 25, 2007

wrote in message:
wrote in message:
You've the string in single quotes, so PHP sends the characters
backslash and en, instead of the newline character you want.

Try pulling the string in double quotes (in both places).

--
==================
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
jstuck...@xxxxxxxxxxx
==================
Hi Jerry,
Thanks for coming back to me. I had originally used double quotes,
but the PHP script seemd to hand (firefox just reported waiting for
server for many minutes). I was obviously have a bad 5 mins, as when
I re-read the section on single vs. double quotes I could work out
why...
I will do some more experimentation.
Chris

Well, it sounds like you need to look at what's actually being
communicated. It could seem to hang of it's waiting for a response from
the remote device

<hardware> (Or "peripheral device", "device") Any part of a
	computer other than the {CPU} or {working memory},
	i.e. {disks}, {keyboards}, {monitors}, {mice}, {printers},
	{scanners}, {tape drives}, {microphones}, {speakers},
	{cameras}, to list just the less exotic ones.

	High speed working {memory}, such as {RAM}, {ROM} or, in the
	old days, {core} would not normally be referred to as
	peripherals.  The more modern term "device" is also more
	general in that it is used for things such as a {pseudo-tty},
	a {RAM drive}, or a {network adaptor}.

	Some argue that, since the advent of the {personal computer},
	the {motherboard}, {hard disk}, keyboard, mouse, and monitor
	are all parts of the base system, and only use the term
	"peripheral" for optional additional components.

	(2002-09-03)

which does not come, for instance.

--
==================
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
jstucklex@xxxxxxxxxxx
==================

From: Can2002

Date: Thursday, October 25, 2007

wrote in message:

Well, it sounds like you need to look at what's actually being
communicated. It could seem to hang of it's waiting for a response from
the remote device which does not come, for instance.

Thanks again Jerry,

I did wonder that, which was what led me to try the single quotes. I
know the box

<computer> 1. A computer; especially in the construction "foo
	box" where foo is some functional qualifier, like "graphics",
	or the name of an {operating system} (thus, "{Unix} box",
	"{MS-DOS} box", etc.)  "We preprocess the data on Unix boxes
	before handing it up to the {mainframe}."  The plural
	"{boxen}" is sometimes seen.

	2. Without qualification in an {IBM} {SNA} site, "box" refers
	specifically to an {IBM} {front-end processor}.

	[{Jargon File}]

	(1994-11-29)

responds after a newline, both from seeing the effect of
removing it from my python app or connecting via Telnet. Am I right
in thinking that echoing "\n" will result in a newline character being
sent?

Sorry if it sounds like a stupid question...

Chris

From: Jerry Stuckle

Date: Thursday, October 25, 2007

wrote in message:
wrote in message:
Well, it sounds like you need to look at what's actually being
communicated. It could seem to hang of it's waiting for a response from
the remote device which does not come, for instance.
Thanks again Jerry,
I did wonder that, which was what led me to try the single quotes. I
know the box responds after a newline, both from seeing the effect of
removing it from my python app or connecting via Telnet. Am I right
in thinking that echoing "\n" will result in a newline character being
sent?
Sorry if it sounds like a stupid question...
Chris

Chris,

Echoing a "\n" won't send it over the socket, but I do not think that's
what you mean.

Sending a "\n" over the socket should send a newline character. But is
your device expecting a new line

1. <hardware> An electrical conductor.  For distances larger
	than a breadbox, a single line may consist of two electrical
	conductors in twisted, parallel, or concentric arrangement
	used to transport one logical signal.

	By extension, a (usually physical) medium such as an {optical
	fibre} which carries a signal.

	(1995-09-29)

(Unix style) or a cr/lf (Windows
style)? If the latter, try "\r\n".

--
==================
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
jstucklex@xxxxxxxxxxx
==================

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