Cronjob, tar, autostart, sudo, grep

cronjob

• execute all listed cronjobs: crontab -l | grep -v '^#' | cut -f 6- -d ' ' | while read CMD; do eval $CMD; done
• send mail address https://de.godaddy.com/blog/behalten-sie-ihre-cron-jobs-unter-kontrolle/

tar

useage: tar [OPTION...] [FILE]... create archive:

• unzipped
  • tar -cf archiv.tar datei_1.txt *.pdf Create archiv.tar with 1 file and all pdfs
  • tar -cf archiv.tar path/ Create archiv.tar with all subdir
  • tar -rf archiv.tar datei_1.txt Add 1 specific file to archiv (unconpressed)
• zipped
  • tar -czf archiv.tar.gz file Create archiv.tar.gz

extract archive:

• tar -xf archiv.tar Extract files
• tar -xzf archiv.tar.gz -C / Extract gzip archives
• tar -xzf archiv.tar.gz -C /path Extract gzip archives to /path

tar -tvf archiv.tar Show which files are in archiv.tar

autostart

• create new file
  • user only sudo nano ~/.config/autostart/<some_name>.desktop
  • global sudo nano /etc/xdg/autostart/<some_name>.desktop
• insert content like:

  [Desktop Entry]
  Type=Application
  Name=Musterprogramm
  Exec=Auszuführendes Kommando
  

sudo

add user to sudo

su -
usermod -aG sudo <username>

no password sudo

• edit sudoers file with sudo visudo
• add line at end of file (important for not be overriten):

  username  ALL=(ALL) NOPASSWD:ALL
  

grep

• arguments:

  • -i, --ignore-case Ignore case distinctions in both the PATTERN and the input files.

• use cases: