# Shell numric and string comparisons

# As numbers

value=1234
if (( $value > 10000 )); then echo "yay 2"; fi
if (( $value > 20000 )); then echo "yay 4"; fi
value=23456
if (( $value > 10000 )); then echo "yay 6"; fi
if (( $value > 20000 )); then echo "yay 8"; fi

# As strings

value=1234
if [[ $value > 10000 ]]; then echo "yay 2"; fi
if [[ $value > 20000 ]]; then echo "yay 4"; fi
value=23456
if [[ $value > 10000 ]]; then echo "yay 6"; fi
if [[ $value > 20000 ]]; then echo "yay 8"; fi

# Arithmetic for loop

for (( i=4,j=12 ; i<12 ; i=i+2,j=j-2 )); do
        echo "looping $i $j"
done

# textual for loop

places='Here there somewhere everywhere nowhere'
for place in $places; do
        echo "I lykes $place"
done

# -------------------------------------------------------
# This block puts things together to make a backup folder
# -------------------------------------------------------

if [ -d tempdemo ]; then
        rm -rf tempdemo.bak
        mv -f tempdemo tempdemo.bak
elif [ -e tempdemo ]; then
        echo "You twit! you have a file called tempdemo"
        exit 1
fi
mkdir tempdemo
for symbol in `ls`; do
        echo "doing $symbol"
        if [ -f $symbol ]; then
                cp -f $symbol tempdemo/$symbol
        fi
done

# ------------- Sample output -------------------
#
# WomanWithCat:bash grahamellis$ bash shelc
# yay 6
# yay 8
# yay 2
# yay 6
# yay 8
# looping 4 12
# looping 6 10
# looping 8 8
# looping 10 6
# I lykes Here
# I lykes there
# I lykes somewhere
# I lykes everywhere
# I lykes nowhere
# doing another
# doing askuser
# doing demo
# doing demo.c
# doing demo.o
# doing eocl
# doing fff
# doing fnk
# doing help
# doing help001
# doing here
# doing makefile
# doing more.c
# doing more.o
# doing pex
# doing railstats.xyz
# doing shelc
# doing temp.txt
# doing tempdemo
# doing umd
# doing umx
# doing wobble
# doing wont
# WomanWithCat:bash grahamellis$