Making a case for case statements on Linux

#!/bin/bash

echo -n "enter the variety of equal sides that the form has> "
learn numsides

# make sure that reply is numeric
re="^[0-9]+$"
if ! [[ $numsides =~ $re ]] ; then
   echo "error: Not a quantity" >&2; exit 1
fi

if [ $numsides -lt 3 ]; then
    echo "Sorry, however that might NOT be a geometrical form"
elif [ $numsides == 3 ]; then
    echo triangle
elif [ $numsides == 4 ]; then
    echo sq. or rectangle
elif [ $numsides == 5 ]; then
    echo pentagon 
elif [ $numsides == 6 ]; then
    echo hexagon 
elif [ $numsides == 7 ]; then
    echo heptagon 
elif [ $numsides == 8 ]; then
    echo octagon 
elif [ $numsides == 9 ]; then
    echo nonagon 
elif [ $numsides == 10 ]; then
    echo decagon 
elif [ $numsides == 11 ]; then
    echo hendecagon 
elif [ $numsides == 12 ]; then
    echo dodecagon 
elif [ $numsides -gt 12 ]; then
    echo "Hmm, you’d higher ask Google"
fi

Utilizing case statements, however, makes your code a lot easier to place collectively and far simpler to learn.

#!/bin/bash

echo -n "enter the variety of equal sides that the form has> "
learn numsides

# make sure that reply is numeric
re="^[0-9]+$"
if ! [[ $numsides =~ $re ]] ; then
   echo "error: Not a quantity" >&2; exit 1
fi

case "$numsides" in
    0-2) echo "Sorry, however that might NOT be a geometrical form";;
    3) echo triangle;;
    4) echo sq. or rectangle;;
    5) echo pentagon;;
    6) echo hexagon;;
    7) echo heptagon;;
    8) echo octogon;;
    9) echo nonagon;;
    10) echo decagon;;
    11) echo hendecagon;;
    12) echo dodecaggon;;
    *) echo "Hmm, you’d higher ask Google"
esac

Every section within the case assertion should finish with two semicolons. Nonetheless, you would use a number of instructions separated by semicolons and solely use the double semicolons on the finish od that section.

Wrap-up

Discover how a lot simpler case instructions are to arrange and preserve. You’ll be able to present any variety of attainable values at the price of one line every.