String Format¶

convert to lowercase¶

${var,,}
# Example: rename files
for fn in *.JPG; do
    mv "$fn" "${fn,,}"
done

convert to uppercase¶

${var^^}

swap case¶

${var~~}

convert to camel case¶

while read txt; do
    a=($txt)      #treat as array init by parentheses, each word an element
    echo ${a[@]^} #[@] references all elements at once, and ^ converts first character to uppercase
done

printf format¶

printf "%-10.10s [%8d]:", i, v[i]

%-10.10s left align and pad to 10 characters but also truncate at 10 characters
%8d assure the integer is printed in an 8-character field (right aligned)