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5

I have a device in /var/iot/data which I'm trying to get the data from remotely.

On the machine itself:

# cat /var/iot/data | xxd -ps -c 32
80de004a030270055678013ac591e5c6abac2185f4319c8088e3

That's the correct data.

If I run the same thing remotely, it looks correct:

$ ssh -T -x dragino 'cat /var/iot/data | xxd -ps -c 32' 
80de004a030270055678013ac591e5c6abac2185f4319c8088e3

But it's actually coming through with a bunch of escape sequences:

$ ssh -T -x dragino 'cat /var/iot/data | xxd -ps -c 32' | xxd
00000000: 1b5d 3131 3b23 3138 3464 3666 0738 3064 .]11;#184d6f.80d
00000010: 6530 3034 6130 3330 3237 3030 3535 3637 e004a03027005567
00000020: 3830 3133 6163 3539 3165 3563 3661 6261 8013ac591e5c6aba
00000030: 6332 3138 3566 3433 3139 6338 3038 3865 c2185f4319c8088e
00000040: 330a 1b5d 3131 3b23 3139 3139 3730 07 3..]11;#191970.

What is all that .]11;#184d6f. at the beginning?

shell ssh terminal

share|improve this question

asked 8 hours ago

Greg BellGreg Bell

33733 silver badges1111 bronze badges

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  I've had this exact problem with echo, it just adds the n at the end and I had no idea why, in your case these are actually the control characters before and after, yet the #184d6f and #191970 makes me wonder why there's a hex color representation there, it's not something that bash usually works with.
  
  – Yaron
  8 hours ago
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Related but not an answer: serverfault.com/a/746638/237978
  
  – Greg Bell
  8 hours ago
  

  
  
  
  


• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  
  Do you have a .bashrc on the remote server? That may be generating those strings. What does `ssh -T -x dragino 'cat /dev/null' | xxd show?
  
  – wurtel
  7 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  The two commands are not equivalent. Could you also try ssh -T -x dragino 'cat /var/iot/data' | xxd -ps -c 32 ? As far as I can see, there is no reason to run xxd remotely.
  
  – Kusalananda♦
  6 hours ago
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  What shell are you using on the dragino machine?
  
  – icarus
  6 hours ago
  

  
  
  
  

add a comment | 

5

I have a device in /var/iot/data which I'm trying to get the data from remotely.

On the machine itself:

# cat /var/iot/data | xxd -ps -c 32
80de004a030270055678013ac591e5c6abac2185f4319c8088e3

That's the correct data.

If I run the same thing remotely, it looks correct:

$ ssh -T -x dragino 'cat /var/iot/data | xxd -ps -c 32' 
80de004a030270055678013ac591e5c6abac2185f4319c8088e3

But it's actually coming through with a bunch of escape sequences:

$ ssh -T -x dragino 'cat /var/iot/data | xxd -ps -c 32' | xxd
00000000: 1b5d 3131 3b23 3138 3464 3666 0738 3064 .]11;#184d6f.80d
00000010: 6530 3034 6130 3330 3237 3030 3535 3637 e004a03027005567
00000020: 3830 3133 6163 3539 3165 3563 3661 6261 8013ac591e5c6aba
00000030: 6332 3138 3566 3433 3139 6338 3038 3865 c2185f4319c8088e
00000040: 330a 1b5d 3131 3b23 3139 3139 3730 07 3..]11;#191970.

What is all that .]11;#184d6f. at the beginning?

shell ssh terminal

share|improve this question

asked 8 hours ago

Greg BellGreg Bell

33733 silver badges1111 bronze badges

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  I've had this exact problem with echo, it just adds the n at the end and I had no idea why, in your case these are actually the control characters before and after, yet the #184d6f and #191970 makes me wonder why there's a hex color representation there, it's not something that bash usually works with.
  
  – Yaron
  8 hours ago
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Related but not an answer: serverfault.com/a/746638/237978
  
  – Greg Bell
  8 hours ago
  

  
  
  
  


• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  
  Do you have a .bashrc on the remote server? That may be generating those strings. What does `ssh -T -x dragino 'cat /dev/null' | xxd show?
  
  – wurtel
  7 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  The two commands are not equivalent. Could you also try ssh -T -x dragino 'cat /var/iot/data' | xxd -ps -c 32 ? As far as I can see, there is no reason to run xxd remotely.
  
  – Kusalananda♦
  6 hours ago
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  What shell are you using on the dragino machine?
  
  – icarus
  6 hours ago
  

  
  
  
  

add a comment | 

I have a device in /var/iot/data which I'm trying to get the data from remotely.

On the machine itself:

# cat /var/iot/data | xxd -ps -c 32
80de004a030270055678013ac591e5c6abac2185f4319c8088e3

That's the correct data.

If I run the same thing remotely, it looks correct:

$ ssh -T -x dragino 'cat /var/iot/data | xxd -ps -c 32' 
80de004a030270055678013ac591e5c6abac2185f4319c8088e3

But it's actually coming through with a bunch of escape sequences:

$ ssh -T -x dragino 'cat /var/iot/data | xxd -ps -c 32' | xxd
00000000: 1b5d 3131 3b23 3138 3464 3666 0738 3064 .]11;#184d6f.80d
00000010: 6530 3034 6130 3330 3237 3030 3535 3637 e004a03027005567
00000020: 3830 3133 6163 3539 3165 3563 3661 6261 8013ac591e5c6aba
00000030: 6332 3138 3566 3433 3139 6338 3038 3865 c2185f4319c8088e
00000040: 330a 1b5d 3131 3b23 3139 3139 3730 07 3..]11;#191970.

What is all that .]11;#184d6f. at the beginning?

shell ssh terminal

share|improve this question

asked 8 hours ago

Greg BellGreg Bell

33733 silver badges1111 bronze badges

# cat /var/iot/data | xxd -ps -c 32
80de004a030270055678013ac591e5c6abac2185f4319c8088e3

$ ssh -T -x dragino 'cat /var/iot/data | xxd -ps -c 32' 
80de004a030270055678013ac591e5c6abac2185f4319c8088e3

$ ssh -T -x dragino 'cat /var/iot/data | xxd -ps -c 32' | xxd
00000000: 1b5d 3131 3b23 3138 3464 3666 0738 3064 .]11;#184d6f.80d
00000010: 6530 3034 6130 3330 3237 3030 3535 3637 e004a03027005567
00000020: 3830 3133 6163 3539 3165 3563 3661 6261 8013ac591e5c6aba
00000030: 6332 3138 3566 3433 3139 6338 3038 3865 c2185f4319c8088e
00000040: 330a 1b5d 3131 3b23 3139 3139 3730 07 3..]11;#191970.

share|improve this question

asked 8 hours ago

Greg BellGreg Bell

33733 silver badges1111 bronze badges

share|improve this question

asked 8 hours ago

Greg BellGreg Bell

33733 silver badges1111 bronze badges

asked 8 hours ago

Greg BellGreg Bell

33733 silver badges1111 bronze badges

asked 8 hours ago

Greg BellGreg Bell

33733 silver badges1111 bronze badges

2 Answers
2

active

oldest

votes

7

The sequences are

OSC 1 1 ; # 1 8 4 d 6 f BEL
OSC 1 1 ; # 1 9 1 9 7 0 BEL

which is are xterm control sequences to request to set the terminal text background color. Probably caused by a badly written shell initialization file which causes these to be output in an attempt to distinguish the output of commands from the shell prompt, but does so unconditionally

share|improve this answer

answered 7 hours ago

icarusicarus

7,39811 gold badge1717 silver badges3333 bronze badges

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  This was it. My fault. Smoking shoe award. I've setup ssh to change my terminal background so I'm always reminded that I'm on a remote machine. Stupid! Will delete the question. Thanks for this decoding Icarus - it's what made the lightbulb turn on.
  
  – Greg Bell
  48 mins ago
  
  

  
  
  
  

add a comment | 

-1

The -T option for ssh will cause the remote SSH server to allocate a virtual terminal for the session and therefore programs (such as the shell) will act accordingly.

For transferring arbitrary data omit the -T option.

share|improve this answer

answered 5 hours ago

Timothy BaldwinTimothy Baldwin

19355 bronze badges

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  You're thinking of the -t option. The -T does the opposite, explicitly disables pseudo-terminal allocation.
  
  – Kusalananda♦
  5 hours ago
  

  
  
  
  

add a comment | 

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7

The sequences are

OSC 1 1 ; # 1 8 4 d 6 f BEL
OSC 1 1 ; # 1 9 1 9 7 0 BEL

which is are xterm control sequences to request to set the terminal text background color. Probably caused by a badly written shell initialization file which causes these to be output in an attempt to distinguish the output of commands from the shell prompt, but does so unconditionally

share|improve this answer

answered 7 hours ago

icarusicarus

7,39811 gold badge1717 silver badges3333 bronze badges

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  This was it. My fault. Smoking shoe award. I've setup ssh to change my terminal background so I'm always reminded that I'm on a remote machine. Stupid! Will delete the question. Thanks for this decoding Icarus - it's what made the lightbulb turn on.
  
  – Greg Bell
  48 mins ago
  
  

  
  
  
  

add a comment | 

7

The sequences are

OSC 1 1 ; # 1 8 4 d 6 f BEL
OSC 1 1 ; # 1 9 1 9 7 0 BEL

which is are xterm control sequences to request to set the terminal text background color. Probably caused by a badly written shell initialization file which causes these to be output in an attempt to distinguish the output of commands from the shell prompt, but does so unconditionally

share|improve this answer

answered 7 hours ago

icarusicarus

7,39811 gold badge1717 silver badges3333 bronze badges

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  This was it. My fault. Smoking shoe award. I've setup ssh to change my terminal background so I'm always reminded that I'm on a remote machine. Stupid! Will delete the question. Thanks for this decoding Icarus - it's what made the lightbulb turn on.
  
  – Greg Bell
  48 mins ago
  
  

  
  
  
  

add a comment | 

The sequences are

OSC 1 1 ; # 1 8 4 d 6 f BEL
OSC 1 1 ; # 1 9 1 9 7 0 BEL

which is are xterm control sequences to request to set the terminal text background color. Probably caused by a badly written shell initialization file which causes these to be output in an attempt to distinguish the output of commands from the shell prompt, but does so unconditionally

share|improve this answer

answered 7 hours ago

icarusicarus

7,39811 gold badge1717 silver badges3333 bronze badges

OSC 1 1 ; # 1 8 4 d 6 f BEL
OSC 1 1 ; # 1 9 1 9 7 0 BEL

share|improve this answer

answered 7 hours ago

icarusicarus

7,39811 gold badge1717 silver badges3333 bronze badges

answered 7 hours ago

icarusicarus

7,39811 gold badge1717 silver badges3333 bronze badges

answered 7 hours ago

icarusicarus

7,39811 gold badge1717 silver badges3333 bronze badges

-1

The -T option for ssh will cause the remote SSH server to allocate a virtual terminal for the session and therefore programs (such as the shell) will act accordingly.

For transferring arbitrary data omit the -T option.

share|improve this answer

answered 5 hours ago

Timothy BaldwinTimothy Baldwin

19355 bronze badges

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  You're thinking of the -t option. The -T does the opposite, explicitly disables pseudo-terminal allocation.
  
  – Kusalananda♦
  5 hours ago
  

  
  
  
  

add a comment | 

-1

The -T option for ssh will cause the remote SSH server to allocate a virtual terminal for the session and therefore programs (such as the shell) will act accordingly.

For transferring arbitrary data omit the -T option.

share|improve this answer

answered 5 hours ago

Timothy BaldwinTimothy Baldwin

19355 bronze badges

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  You're thinking of the -t option. The -T does the opposite, explicitly disables pseudo-terminal allocation.
  
  – Kusalananda♦
  5 hours ago
  

  
  
  
  

add a comment | 

The -T option for ssh will cause the remote SSH server to allocate a virtual terminal for the session and therefore programs (such as the shell) will act accordingly.

For transferring arbitrary data omit the -T option.

share|improve this answer

answered 5 hours ago

Timothy BaldwinTimothy Baldwin

19355 bronze badges

share|improve this answer

answered 5 hours ago

Timothy BaldwinTimothy Baldwin

19355 bronze badges

answered 5 hours ago

Timothy BaldwinTimothy Baldwin

19355 bronze badges

answered 5 hours ago

Timothy BaldwinTimothy Baldwin

19355 bronze badges