Shell

insert a string after every N lines
1, sed ‘0~1000 s/$/new line;/g’ < aaa > bbb.new

date
1, date -d “2015-12-25” ‘+%m-%d-%y’ && date -d “2015-12-25” “+A %A in %B”

bash parameter test

#!/bin/bash

echo "Using \"\$*\":"
for a in "$*"; do
    echo $a;
done

echo -e "\nUsing \$*:"
for a in $*; do
    echo $a;
done

echo -e "\nUsing \"\$@\":"
for a in "$@"; do
    echo $a;
done

echo -e "\nUsing \$@:"
for a in $@; do
    echo $a;
done

other

1. echo ‘10.9.8.11 server01’

   sudo tee -a /etc/hosts