Some miscellaneous linux hints - crontab, ISO handlin, shared libaries debugging.

Crontab

Just an example 😁. Edit cron tables with crontab -e.

#https://www.pantz.org/software/cron/croninfo.html
# Minute   Hour   Day of Month       Month          Day of Week        Command
# (0-59)  (0-23)     (1-31)    (1-12 or Jan-Dec)  (0-6 or Sun-Sat)
 */5       *          *                *                *  export DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/1000/bus; export DISPLAY=:0; . $HOME/.profile;  cronbat
  0        */1        *                *                *  export DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/1000/bus; export DISPLAY=:0; . $HOME/.profile;  checkup

Install ISO to pendrive

Arch linux article

# DD isn't best but at least has progressbar
dd bs=4M if=path/to/archlinux.iso of=/dev/sdx status=progress oflag=sync

Shared libraries

Checking what shared libraries are needed:

  • readelf -d <binary> - view elf headers of binary. it shows required shared libraries
  • ldd <binary> - similar, but shows more info and shows if lib is installed