Linux: Tips & Tricks

gistfile1.txt

Find all files between a start-date, and an end-date:

( touch -t $(date --date='6 months ago' +%Y%m%d"0000") /tmp/start && touch -t $(date --date='5 months ago' +%Y%m%d"0000") /tmp/stop ) && find . -newer /tmp/start \! -newer /tmp/stop -exec ls -l {} \; | less


Some Bash variables tricks:
$ set quick brown fox jumps

$ echo ${*: -1:1} # last argument
jumps

$ echo ${*: -1} # or simply
jumps

$ echo ${*: -2:1} # next to last
fox


# Variable expansion.
# TL;DR Loop through a list of variable names, expanding their contents into another variable.
# Use variables to hold stuff - like SQL queries etc, use a for loop to go through the list of variables
# extracting their content into another variable, or use the result directly.

var1="blah blah"
var2="foo bar"

varnames="var1 var2"

for var in $varnames
do
  # Extract the contents of the variable in the list in varnames
  contents="$(eval echo \$$var)"
  
  echo "var \$contents now contains the value held in \$$var"
  
  echo "\$var = $var"
  echo "\$contents = $contents"
 done