# CR/LF in data read from a socket

**URL:** <https://www.ruby-forum.com/t/cr-lf-in-data-read-from-a-socket/53063>\
**Category:** Ruby\
**Created:** [January 24, 2006, 3:57pm UTC](https://www.ruby-forum.com/t/cr-lf-in-data-read-from-a-socket/53063 "2006-01-24T15:57:10Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![mac](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/cc9497/32.png) [@mac](https://www.ruby-forum.com/u/mac)\
**Post date:** [January 24, 2006, 3:57pm UTC](https://www.ruby-forum.com/t/cr-lf-in-data-read-from-a-socket/53063/1 "2006-01-24T15:57:10Z")

</div>

Hello,  
I am trying to write a client/server program in an effort to learn Ruby.  
I  
have been playing around with Ruby for about 2 months and I really love  
it.  
As I developed my program (DICOM tool kit) I am faced with an issue on  
which  
I spend almost a day to figure out. I know what is happening but don’t  
know  
why and how to correct it. Any pointers will help. Thanks. Here it is:

++++++++++++++++++++++++++++++++++++++++  
Snippet of the code:

.

# open the socket

require ‘socket’  
port =4010  
server = TCPServer.new(‘localhost’, port)  
while (session = server.accept)

}  
.  
.  
.

# read the stream

ind=0  
while msgCtrlHdr!= 2  
p “Inside handleC\_STORE\_RQ Entering Loop…”

# read next PDU

pduType= session.getc  
printf(“PDU Type = %d\n”,pduType)

# read the pdu length and the pdu itself.

pduLength=session.read(5).unpack(‘xN’)[0]  
print “pduLength =”,pduLength,"\n"  
pdu=session.read(pduLength)  
itemLength, presCtxt=pdu.slice!(0,5).unpack(‘Nc’)  
print “itemLength =”,itemLength," presCtxt =",presCtxt,"\n"  
msgCtrlHdr=pdu.slice!(0,1).unpack(‘c’)[0]  
outputFile = File.new( “test\_image”+ind.to\_s,“w”)  
outputFile.syswrite(pdu)  
ind=ind+1  
image \<\< pdu  
#printf(“Image Length = %d\n”,image.length)  
end

++++++++++++++++++++++++++++++++++++++++++++++++++

As you can see mine is the server part and the client is a standard Java  
program that sends out images, I did not write it, it is a commercial  
program.  
When I load the output file in to a hex editor (Ultraedit) I see “0D”  
and  
“0A” chars (CR and LF) in the file, several of them where they should  
not  
be.  
Following is a snippet of the data from ultra edit.

00000000h: 08 00 00 00 04 00 00 00 A0 01 00 00 08 00 08 00 ;  
… …  
00000010h: 1A 00 00 00 4F 52 49 47 49 4E 41 4C 5C 50 52 49 ;  
…ORIGINAL\PRI  
00000020h: 4D 41 52 59 5C 55 4E 44 45 46 49 4E 45 44 08 00 ;  
MARY\UNDEFINED…  
00000030h: 16 00 1A 00 00 00 31 2E 32 2E 38 34 30 2E 31 30 ;  
…1.2.840.10  
00000040h: 30 30 38 2E 35 2E 31 2E 34 2E 31 2E 31 2E 34 00 ;  
008.5.1.4.1.1.4  
.  
00000050h: 08 00 18 00 34 00 00 00 31 2E 33 2E 31 32 2E 32 ;  
…4…1.3.12.2  
00000060h: 2E 31 31 30 37 2E 35 2E 38 2E 31 2E 31 32 33 34 ;  
.1107.5.8.1.1234  
00000070h: 35 36 37 38 39 2E 31 39 39 35 30 37 32 37 31 37 ;  
56789.1995072717  
00000080h: 35 38 30 35 30 37 30 37 37 36 35 00 08 00 20 00 ;  
58050707765…  
.  
00000090h: 08 00 00 00 31 39 39 34 30 36 31 33 08 00 22 00 ;  
…19940613…".  
000000a0h: 08 00 00 00 31 39 39 34 30 36 31 33 08 00 23 00 ;  
…19940613…#.  
000000b0h: 08 00 00 00 31 39 39 34 30 36 31 33 08 00 30 00 ;  
…19940613…0.  
000000c0h: _0D 0A_ 00 00 00 31 35 33 32 32 36 2E 33 39 32 08 ;  
…153226.392.  
000000d0h: 00 32 00 _0D 0A_ 00 00 00 31 35 33 32 32 37 2E 37 ;  
.2…153227.7  
000000e0h: 33 30 08 00 33 00 _0D 0A_ 00 00 00 31 35 33 35 32 ;  
30…3…15352  
000000f0h: 35 2E 30 30 30 08 00 40 00 02 00 00 00 00 00 08 ; 5.000.  
.@…  
00000100h: 00 41 00 08 00 00 00 49 4D 41 20 4E 4F 4E 45 08 ; .A…IMA  
NONE.  
00000110h: 00 50 00 _0D 0A_ 00 00 00 53 4D 53 30 30 30 30 31 ;  
.P…SMS00001  
00000120h: 33 20 08 00 60 00 02 00 00 00 4D 52 08 00 70 00 ; 3  
…`…MR…p.  
00000130h: 08 00 00 00 53 49 45 4D 45 4E 53 20 08 00 80 00 ; …SIEMENS  
…â?¬.  
00000140h: 1A 00 00 00 44 69 61 67 20 52 61 64 69 6F 6C 6F ; …Diag  
Radiolo  
00000150h: 67 79 20 47 72 6F 73 73 68 61 64 65 72 6E 08 00 ; gy  
Grosshadern…  
00000160h: 90 00 00 00 00 00 08 00 10 10 1A 00 00 00 44 69 ;  
…Di  
00000170h: 61 67 20 52 61 64 69 6F 6C 6F 67 79 20 47 72 6F ; ag  
Radiology  
Gro  
00000180h: 73 73 68 61 64 65 72 6E 08 00 30 10 00 00 00 00 ;  
sshadern…0…  
00000190h: 08 00 80 10 00 00 00 00 08 00 90 10 10 00 00 00 ;  
…â?¬……  
000001a0h: 4D 41 47 4E 45 54 4F 4D 20 56 49 53 49 4F 4E 20 ; MAGNETOM  
VISION

000001b0h: 09 00 00 00 04 00 00 00 A0 01 00 00 09 00 10 00 ;  
… …  
000001c0h: 0E 00 00 00 53 50 49 20 52 45 4C 45 41 53 45 20 ; …SPI  
RELEASE

000001d0h: 31 20 09 00 12 00 14 00 00 00 53 49 45 4D 45 4E ; 1  
…SIEMEN  
000001e0h: 53 20 43 4D 20 56 41 30 20 20 43 4D 53 20 09 00 ; S CM VA0  
CMS  
…  
000001f0h: 13 00 14 00 00 00 53 49 45 4D 45 4E 53 20 43 4D ;  
…SIEMENS  
CM  
00000200h: 20 56 41 30 20 20 4C 41 42 20 09 00 10 10 12 00 ; VA0 LAB  
…

---

<div class="post-metadata">

**Author:** ![mac](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/cc9497/32.png) [@mac](https://www.ruby-forum.com/u/mac)\
**Post date:** [January 25, 2006, 8:55am UTC](https://www.ruby-forum.com/t/cr-lf-in-data-read-from-a-socket/53063/2 "2006-01-25T08:55:53Z")

</div>

mac schrieb:

> outputFile = File.new( “test\_image”+ind.to\_s,“w”)  
> outputFile.syswrite(pdu)  
> …  
> When I load the output file in to a hex editor (Ultraedit) I see “0D” and  
> “0A” chars (CR and LF) in the file, several of them where they should not  
> be.

Hi Mac,

if you’re on Windows you have to open the output file in binary mode:

outputFile = File.new( “test\_image”+ind.to\_s, “wb” )

Also look at the block form of File.open to automatically close the  
output file.

Regards,  
Pit

---

<div class="post-metadata">

**Author:** ![mac](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/cc9497/32.png) [@mac](https://www.ruby-forum.com/u/mac)\
**Post date:** [January 26, 2006, 5:44am UTC](https://www.ruby-forum.com/t/cr-lf-in-data-read-from-a-socket/53063/3 "2006-01-26T05:44:15Z")

</div>

Pit,  
Thanks for the correction, that fixed it! Really appreciate it.  
There is obiviously lack of dacumentation in Ruby world.

---

<div class="post-metadata">

**Author:** ![mac](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/cc9497/32.png) [@mac](https://www.ruby-forum.com/u/mac)\
**Post date:** [January 26, 2006, 6:44am UTC](https://www.ruby-forum.com/t/cr-lf-in-data-read-from-a-socket/53063/4 "2006-01-26T06:44:36Z")

</div>

mac wrote:

> Pit,  
> Thanks for the correction, that fixed it! Really appreciate it.  
> There is obiviously lack of dacumentation in Ruby world.

I had to respond to this. I’m not sure if you’re comparing to  
java/.NET, or maybe perl/python or lisp/smalltalk/ML/some of those  
kinds of environments. There actually is heaps of info on the net.  
I’ve seen people produce lots of top-quality code in response to  
queries on this mail list, really detailed analysis, etc. It’s really  
extraordinary, sometimesyou have to ask.