Empty variable detection (Bash)
Naar navigatie springen
Naar zoeken springen
Variables
# Initialisation ######################################## # echo ""; echo ""; echo "### rename_slugs_and_titles_image_wizard_pages()..."; echo "" if [ -z "$path" ]; then echo " Variable 'path' not provided. Exiting"; exit; fi cd $path
Arrays
With #
, the length of the array is returned, like in echo ${#myarray[@]}
. That's how these examples work:
# # Test at start of script ######################################## # if (( ${#tr_f[@]} == 0 )); then echo "Before unset - Empty" else echo "Before unset - Not empty" fi # Unset + test ######################################## # unset tr_f # # if (( ${#tr_f[@]} == 0 )); then echo "After unset, before declare - Empty" else echo "After unset, before declare - Not empty" fi # Declare + test ######################################## # declare -A tr_f i=0 # Fill array ######################################## # ((i++)) tr_f[$i,1]="One" tr_f[$i,2]="Einz" ((i++)) tr_f[$i,1]="Two" tr_f[$i,2]="Zwei" # Last test ######################################## # if (( ${#tr_f[@]} == 0 )); then echo "After assigning values - Empty" else echo "After assigning values - Not empty" fi