bash scripting practice: batch add users
#bash #scripting #bashsyntax #UofTBootCamp #homework
Takeaways
- quotes around the
array
in afor
loop is best practice:
Without them, the
for
loop will break up the array by substrings separated >by any spaces within the strings instead of by whole string elements within >the array. ie: if you haddeclare -a arr=("element 1" "element 2" "element 3")
, >thenfor i in ${arr[@]}
would mistakenly iterate 6 times since each string >becomes 2 substrings separated by the space in the string, whereas fori in >"${arr[@]}"
would iterate 3 times, correctly, as desired, maintaining each >string as a single unit despite having a space in it.
- you can only capture with
echo
. Usingreturn
is the same asexit
(so you can only capture the exit code)
Syntax Quickies
quick init + iteration
read -a arr <<< "one two three"
for i in ${arr[@]}
do
echo $i
done
- access elements
passing multiple arrays as arguments
`takesaryas_arg() { declare -a argAry1=(“${!1}”) echo “${argAry1[@]}”
declare -a argAry2=(“${!2}”) echo “${argAry2[@]}” } trywithlocalarys() { # array variables could have local scope local descTable=( “sli4-iread” “sli4-iwrite” “sli3-iread” “sli3-iwrite” ) local optsTable=( “—msix —iread” “—msix —iwrite” “—msi —iread” “—msi —iwrite” ) takesaryasarg descTable[@] optsTable[@] } trywithlocal_arys`