push: 
array=("${array[@]}" $new_element) 

pop: 
array=(${array[@]:0:$((${#array[@]}-1))}) 

shift: 
array=(${array[@]:1}) 

unshift 
array=($new_element "${array[@]}") 

function del_array { 
local i 
for (( i = 0 ; i < ${#array[@]} ; i++ )) 
do 
if [ "$1" = "${array[$i]}" ] ;then 
break 
fi 
done 
del_array_index $i 
} 

function del_array_index { 
array=(${array[@]:0:$1} ${array[@]:$(($1 + 1))}) 
}