Wednesday, February 6, 2013

bash survival kit

  • Useful commands 
    - disk activity per process and thread, IO monitor, disk access including swapping
    - iotop -o
    - lsof (List files/network connections open by user)
    --lsof -i:80 (processes listening on port 80) - see also lsof description 
    - dmesg |less
    - uname -a
    - du -sh * (Folders size)
    - du -sh * | sort -nr | head -10 (biggest subfolders)
    - ls -l | grep '^d' (list only directories)
    - watch 'ps aux | grep someprocess' (execute periodically a command)
    - ssh -X toto@machine (enables X11)
    - ajust time and start ntp date tracking:
    - - /etc/init.d/ntp stop
    - - ntpdate 0.debian.pool.ntp.org (synchronize computers time)
    - - /etc/init.d/ntp start
    - - see /etc/ntp.conf - to kill all XServer sessions: "sudo killall Xorg"
    - tunnel: ssh -f -L 10.193.129.2:9090:192.168.0.202:8080 192.168.50.99
    - sudo fuser -v 12001/tcp    (check which process/user is using a port)
    - nslookup: get the name from a remote machine from its IP
    - check if  a remote machine port is open:
    -- wget -qS -O- http://csimg.toto.me:80
    -- curl http://csimg.toto.me:80 
  • route (to see the gateway)
  • open ports
    • netstat -ltu   (local)
    • nmap (not showing all open ports, can be remote)
    • sudo nmap -sU  -p 500 192.168.1.254   (check internet key exchange port open, used for vpn)
  • most recent java files in the tree
    • find . |grep "\.java" |xargs ls -l|awk -F$' ' '{print $6 " " $7 " " $9}' |sort
  • swap per process
    • for file in /proc/*/status ; do awk '/VmSwap|Name/{printf $2 " " $3}END{ print ""}' $file; done
  • find
    • find . -name pom.xml | xargs grep 3.5 --color      (emacs/dired to replace)
    • find . -name '*.log.*' -delete 
    • find . | xargs wc (count the number of files in a folder and sub-directories)
  • grep
    • grep -o OTHERS tb-201610.sql |wc  (new line)
    • grep -P "\t8" file1.txt |awk -F$'\t' '{print $1}' |while read -r x; do grep "$x" file2.txt; done
    • look for multiple values
      • egrep "126|127|128|129|130|131|132|133" toto.txt
  • System 
    • sudo bash (remain as root)
    • uname -a
    • less /proc/meminfo
    • less /proc/cpuinfo
    • lspci -v | less (list all PCI devices connected to the PCI bus)
    • dmesg | less (kernel boot messages)
    • ls -1R | wc -l (number of files in a folder)
    • fdisk -l (disks on a machine)
    • dmidecode (physical processor info)
    • ps auxf  (process tree), 
    • ps -efj   (ppid)
    • ppid:  use htop F2
    • uptime   (when did the machine restarted)
  • DNS
    • dig cnn.com
  • load CPU:
  • for i in {1..1000000}; do gzip speetest;gunzip speetest.gz ;done
    .
    for f in $(find . -name "*.db" | grep 'rep_13' | grep run | xargs ls -1); do echo $f;done .
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awk survival kit


look for a string in the 28th colon in a tsv:

awk -F$'\t' '{if($28 == "popcorn") print $0;}' toto.tsv
awk -F$'\t' '{print $18}' wm_marchand_Data.txt | sort -u
awk -F$'\t' '{print $2 "\t" $1}' sb.txt

for special caracters:
iconv -f ISO-8859-1 -t utf8 ri_thesaurus_v2_Data_LG161___.txt > ri_thesaurus_v2_Data_LG161____.txt
iconv -f utf8 -t ISO-8859-1//TRANSLIT lbm-ko-full-201806.csv > lbm-ko-full-201806-ISO8859.csv
  • keep numbers after = in the output
awk -F$' ' '{print $11}' noc.log  | sed -r 's/.*=([0-9]+)/\1/g'
  • keep only numbers
awk -F':' '{print $3}'  1300-siren.txt | sed -r 's/[^0-9]//g'
  • sort by full number
awk -F$' ' '{print $11}' noc.log  |sed -r 's/.*=([0-9]+)/\1/g' | sort -k1,1n > noc-out.log

  • grep -P "\t8" file1.txt |awk -F$'\t' '{print $1}' |while read -r x; do grep "$x" file2.txt; done
  • to find out swap
for file in /proc/*/status ; do awk '/VmSwap|Name/{printf $2 " " $3}END{ print ""}' $file; done| awk -F$' ' '{print $2}'  |sort  -k1,1n

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