Common command for screen

Reference https://www.rackaid.com/blog/linux-screen-tutorial-and-how-to/

Linux Screen allows you to:

• Use multiple shell windows from a single SSH session.
• Keep a shell active even through network disruptions.
• Disconnect and re-connect to a shell sessions from multiple locations.
• Run a long running process without maintaining an active shell session.

1. Start screen
$ screen

2 Create a screen
$ Ctr+a, c

3. Switch next screen
$ Ctr+a, n

4. List screen
$ screen -ls

5. Deattach screen
$ Ctr+a, d
or terminate
$ Ctr+a, k

6. Reattach screen
$ screen -r <screenid>

ssh forward port to solve denied server port

Sometimes, some port is denied from servers. When you want to access webpage set in server, you can forward remote port to local.

$ ssh -L16006:localhost:6006 user1@remote_server

Set port 6006 at remote server, and you can access at client via port 16006.

Nvidia driver version mismatch (which cause tensorflow gpu not work)

Problem:
When using tensorflow-gpu, get the following error:

Solved in the environment Ubuntu 16.04.

tensorflow/stream_executor/cuda/cuda_driver.cc:406] failed call to cuInit: CUDA_ERROR_NO_DEVICE

1. May be the nvidia driver version problem. Check the installed driver.

$ nvidia-smi

Failed to initialize NVML: Driver/library version mismatch

Show installed nvidia driver
$ dpkg --get-selections | grep nvidia
nvidia-375 install
nvidia-384 install
nvidia-opencl-icd-375 deinstall
nvidia-opencl-icd-384 install
nvidia-prime install
nvidia-settings install

$ dpkg -l | grep -i nvidia

ii  bbswitch-dkms                              0.8-3ubuntu1                                  amd64        Interface for toggling the power on NVIDIA Optimus video cards
ii  libcuda1-375                               375.82-0ubuntu0~gpu16.04.1                    amd64        NVIDIA CUDA runtime library
ii  nvidia-375                                 375.82-0ubuntu0~gpu16.04.1                    amd64        NVIDIA binary driver - version 375.82
ii  nvidia-opencl-icd-375                      375.82-0ubuntu0~gpu16.04.1                    amd64        NVIDIA OpenCL ICD
ii  nvidia-prime                               0.8.2                                         amd64        Tools to enable NVIDIA's Prime
ii  nvidia-settings                            384.90-0ubuntu0~gpu16.04.1                    amd64        Tool for configuring the NVIDIA graphics driver

2. Uninstall current driver and reinstall nvidia-375

$nvidia-uninstall

If there is no nvidia-uninstall, you should remove all nvidia driver

1. Run sudo apt-get purge nvidia-*
2. Run sudo add-apt-repository ppa:graphics-drivers/ppa and then sudo apt-get update.
3. Run sudo apt-get install nvidia-375.
4. Reboot and your graphics issue should be fixed.

You can check your installation status with the following command

lsmod | grep nvidia

Done! Then the "nvidia-smi" should work.

3. May turn off the ubuntu automatical updates.

Other helpful commands.
to list the devices

ubuntu-drivers devices




4. Important. Prevent driver auto-update
Sometimes, only this step is enough!!!

$ sudo apt-mark hold nvidia-375
$ dpkg --get-selections | grep nvidia
nvidia-375 hold
nvidia-384 install
nvidia-opencl-icd-384 install
nvidia-prime install

nvidia-settings install

5. Check tensorflow

import tensorflow as tf
# Creates a graph.
a = tf.constant([1.0, 2.0, 3.0, 4.0, 5.0, 6.0], shape=[2, 3], name='a')
b = tf.constant([1.0, 2.0, 3.0, 4.0, 5.0, 6.0], shape=[3, 2], name='b')
c = tf.matmul(a, b)
# Creates a session with log_device_placement set to True.
sess = tf.Session(config=tf.ConfigProto(log_device_placement=True))
# Runs the op.
print(sess.run(c))

I tensorflow/core/common_runtime/gpu/gpu_device.cc:940] Found device 0 with properties: 
name: GeForce GTX TITAN X

Batch file process in linux bash

Batch process *.ext files

Template

$ find /path/ -name *.ext -exec sh -c 'command "$1"' _ {} \;

Example

print file names without extension
$ find /path/ -name *.ext -exec sh -c 'echo "${1%.*}"' _ {} \;
print base name (dirname), directory (dirname)
$ find /path/ -name *.ext -exec sh -c 'echo $(basename "$1")' _ {} \;

Batch convert *.ext to *.ext_bak

Template

$ find /path/ -name *.ext -exec sh -c 'convert "$1" "${1%.*}".ext_bak' _ {} \;

Example

convert egg to bam file
$ find /path/ -name *.egg -exec sh -c 'egg2bam "$1" -o "${1%.*}".bam' _ {} \;