Linux Tips and Tricks

Introduction

Here is a collection of Linux commands that I find useful:

• Search for all inp-files that contain the text “PENALTY” (case insensitive)

  grep --include=\*.inp -rnwli ~ -e "PENALTY"

• List what hosts are active on the local network:

  arp-scan -l
  nmap -sn 192.168.86.0/24

• Debugging a core dump:

  gdb executable core
  thread apply all bt

• To determine if a Redhat / CentOS computer needs to be rebooted:

  sudo needs-restarting -r

• Enable core dumps on Redhat / CentOS. As root type (needs to be done after each reboot):

  echo /tmp/core-%e-sig%s-user%u-group%g-pid%p-time%t > /proc/sys/kernel/core_pattern

• Split and combine HUGE files:

  split --verbose -b1G file.tar file.tar.
  cat file.tar.* > file.tar

• Update PolyUMod and MCalibration files (the \ before cp runs the command without any alias):

  cd PolyUMod_Installer_Lin64_vX.X.X/files
  \cp -r -p * /opt/PolymerFEM/

• Run ANSYS in batch mode from a Windows PowerShell:

  C:/"Program Files"/"ANSYS Inc"/v192/ansys/bin/winx64/ANSYS192.exe -b -i simulation.dat -o job.output -j job

In the comments below, indicate what important (and “tricky”) commands that you would like to add!