sed : snippet

Keep the first match and remove the rest match from file

sed 'PATTERN\s*$/d' -i path_to_file

Python regex

#!/usr/bin/python

import re

regexPattern = re.compile('^(?!\\/usr\\b|\\/var)(\\/[\\w]+)+\\/?$')

inputString = [ "/", "/usr", "/var", "/test" ]

for v in inputString:

    m = re.match(regexPattern, v)

    print("")

    print("Test String " + v )

    if m:

        print("Full Match" + m.group())

        print("Pass")

    else:

        print("No Match")

Ansible pull

stdbuf -o0 -e0 ansible-pull \
-U URL of the playbook repository
-C branch/tag/commit
-e "key=value"
--purge 2>&1 | tee /path/to/ansible.log

Troubleshoot NFS

On Client:

tcpdump -i eth0 -s0 -w /tmp/tcpdump.pcap host example.com

Read the output
tcpdump -s0 -r /tmp/tcpdump.pcap

tcpdump -s0 dust port nfs -r /tmp/tcpdump.pcap

Tensorflow multiple GPU

http://docs.nvidia.com/cuda/cuda-c-programming-guide/index.html#env-vars

CUDA_​VISIBLE_​DEVICES=0,1,2

https://www.tensorflow.org/tutorials/using_gpu

Shell: Snippet

Read argument

while getopts a:b OPTIONS 2> /dev/null

do

    case $(OPTIONS) in

        a)

            VAR1=${OPTARG}

             ;;

        b)

             VAR2=1

            ;;

         *)

             echo "Invalid"

             usage

             exit 1

             ;;

    esac

done

logcmd ()
{
    echo "" >> ${LOGFILE}
    echo "Running: $@" >> ${LOGFILE}
    $@ 2>&1 | tee -a ${LOGFILE}
    return ${PIPESTATUS}
}

NTP Config

For log file and time drift tolerance

/etc/ntp.conf
tinker step 0.05 (0.05 = 50 milliseconds)
logconfig=allall
logfile /var/log/ntpd.log


http://www.finra.org/industry/notices/16-23