What's the best way to convert a literal string (e.g. "True" into the appropriate bash boolean variable). For instance java has java.lang.Boolean.valueOf(String)
Right now I'm using this in Bash:
if [ "${answers[2]}" = "TRUE" ] ; then clean=true; else clean=false; fi is there a way to do it and avoid the IF statement?
edit: to clarify its not by choice that I have String variable containing "TRUE" instead of just using a boolean variable. for full context this is the code
ans=$(yad --title='YadExample' --form --field=Opt1:CHK FALSE --field=Opt2:CHK FALSE --field=Opt3:CHK TRUE); #at this point the "yad" program is returning a string seperated by '|', e.g "TRUE|FALSE|TRUE" IFS="|" set -- $ans answers=( $@ ) unset IFS if [ "${answers[0]}" = "TRUE" ] ; then clean=true; else clean=false; fi if [ "${answers[1]}" = "TRUE" ] ; then var2=true; else var2=false; fi if [ "${answers[2]}" = "TRUE" ] ; then var3=true; else var3=false; fi 2 Answers
You could write a function to do the conversion for you:
function boolean() { case $1 in TRUE) echo true ;; FALSE) echo false ;; *) echo "Err: Unknown boolean value \"$1\"" 1>&2; exit 1 ;; esac } answers=(TRUE FALSE TRUE) clean="$(boolean "${answers[0]}")" var2="$(boolean "${answers[1]}")" var3="$(boolean "${answers[2]}")" echo $clean $var2 $var3 prints
true false true Or, a little fancier:
function setBoolean() { local v if (( $# != 2 )); then echo "Err: setBoolean usage" 1>&2; exit 1 ; fi case "$2" in TRUE) v=true ;; FALSE) v=false ;; *) echo "Err: Unknown boolean value \"$2\"" 1>&2; exit 1 ;; esac eval $1=$v } answers=(TRUE FALSE TRUE) setBoolean clean "${answers[0]}" setBoolean var2 "${answers[1]}" setBoolean var3 "${answers[2]}" echo $clean $var2 $var3 You can just use something like:
[ "${answers[2]}" != "TRUE" ] ; clean=$? You need to reverse the sense of the comparison if you want clean set to 1 on the condition being true.
Your sequence then becomes:
[ "${answers[0]}" != "TRUE" ] ; clean=$? [ "${answers[1]}" != "TRUE" ] ; var2=$? [ "${answers[2]}" != "TRUE" ] ; var3=$? 
