Some cool Bash Scripts

1. Weather
   

 

  

weather(){ curl -s "wttr.in/$1?m1"}

2. Timer

function count() {

total=$1

for ((i=total; i>0; i--)); do sleep 1; printf "Time remaining $i secs \r"; done

echo -e "\a"

}

   

3. Up

function up() {

times=$1

while [ "$times" -gt "0" ]; do

cd ..

times=$(($times - 1))

done

}

Needn’t do cd ../../.. any longer. Just do up 3.

  

4. Program for Extract.

function extract () {

if [ -f $1 ] ; then

case $1 in

*.tar.bz2) tar xvjf $1 ;;

*.tar.gz) tar xvzf $1 ;;

*.tar.xz) tar Jxvf $1 ;;

*.bz2) bunzip2 $1 ;;

*.rar) rar x $1 ;;

*.gz) gunzip $1 ;;

*.tar) tar xvf $1 ;;

*.tbz2) tar xvjf $1 ;;

*.tgz) tar xvzf $1 ;;

*.zip) unzip -d `echo $1 | sed 's/\(.*\)\.zip/\1/'` $1;;

*.Z) uncompress $1 ;;

*.7z) 7z x $1 ;;

*) echo "don't know how to extract '$1'" ;;

esac

else

echo "'$1' is not a valid file!"

fi

}

 

Who has time in the world to figure out the right extract commands for all the possible formats.

 

5. Trap forced exit of bash script.

Don't let your script exist unexpectedly, trap when someone press ctrl+c  and exit from your script gracefully.

bash script:

trap ctrl_c INT

function ctrl_c() {
echo "** Trapped CTRL-C"
} 

for i in `seq 1 5`; do 

sleep 1 

echo -n "."

done

6. colorful banner with figlet and lolcat

apt-get install figlet lolcat 

 

echo "test"  | figlet

 

echo "testing"  | lolcat

 

ll | lolcat

7. Get First day and last day of the month with using bash script.

#!/bin/bash
# last day for month
if [ ! -n "$1" ]; then
        echo "please pass parameters."
        echo "script.sh YYYY MM"
        exit 0
fi
lastday()  {
#                ja   fe   ma   ap   ma   jn   jl   ag   se   oc   no   de
  mlength=('xx' '31' '28' '31' '30' '31' '30' '31' '31' '30' '31' '30' '31')

  year=$1
  month=$2

  if [ $month -ne 2 ] ; then
    echo ${mlength[$month]}
    return 0
  fi

  leap=0
  ((!(year%100))) && { ((!(year%400))) && leap=1 ; } || { ((!(year%4))) && leap=1 ; }

  feblength=28
  ((leap)) && feblength=29
  echo $feblength
}

# date to Julian date
date2jd() {

  year=$1
  month=$2
  day=$3
  lday=$(lastday $year $month) || exit $?

  if ((day<1 || day> lday)) ; then
    echo day out of range
    exit 1
  fi

  echo $(( jd = day - 32075
                + 1461 * (year + 4800 - (14 - month)/12)/4
                        + 367 * (month - 2 + (14 - month)/12*12)/12
                    - 3 * ((year + 4900 - (14 - month)/12)/100)/4
                - 2400001 ))
}

jd2dow()
{
  days=('Sunday' 'Monday' 'Tuesday' 'Wednesday' 'Thursday' 'Friday' 'Saturday')

  jd=$1
  if ((jd<1 || jd>782028)) ; then
    echo julian day out of range
    return 1
  fi

  ((dow=(jd+3)%7))

  echo ${days[dow]}
}


echo -n "The first day is 01-$1-$2,-- "
fday="$1-$2-01"
echo -n "$fday"
jd2dow $(date2jd $1 $2 01)

echo -n "The last day is $(lastday $1 $2)-$1-$2,-- "
lday="$1-$2-$(lastday $1 $2)"
echo -n "$lday"
jd2dow $(date2jd $1 $2 $(lastday $1 $2))

How to run:

./script 2021 12