Bash Cheat Sheet

  
An entire array can be assigned by enclosing the array items in parenthesis: 
arr=(Hello World)
  arr[0]=Hello
  arr[1]=World

 ${arr[*]}         # All of the items in the array   ${!arr[*]}        # All of the indexes in the array   ${#arr[*]}        # Number of items in the array   ${#arr[0]}        # Length of item zero

GIT
squash commits
git commit --amend --no-edit --all && git push --force-with-lease

git reset
 git rm --cached -r .
 git reset --hard

Update local branch with master changes
 git checkout mybranch      # gets you "on branch mybranch"
 git fetch origin        # gets you up to date with origin
 git merge origin/master

Tag commits 

git ls-remote --tags origin
git tag -a 1.3.3 -m "bump to version 1.3.3"
git push --tags


read a file line by line
     while read LINE; do
         # Do what you want to $LINE
     done < filename


Uptime check
URL=gadban.de
while true; do echo -n "$(date '+%Y%m%d_%H:%M:%S') - "; curl -o /dev/null -s -S -m3 -w "Total: %{time_total}s  Response:%{http_code}\n" $URL  ; sleep 30.9; done