Capitalize strings in sed or awk

Question

I have three types of strings that I'd like to capitalize in a bash script. I figured sed/awk would be my best bet, but I'm not sure. What's the best way given the following requirements?

1. single word
   e.g. taco -> Taco

2. multiple words separated by hyphens
   e.g. my-fish-tacos -> My-Fish-Tacos

3. multiple words separated by underscores
   e.g. my_fish_tacos -> My_Fish_Tacos

Answer 1

There's no need to use capture groups (although & is a one in a way):

echo "taco my-fish-tacos my_fish_tacos" | sed 's/[^ _-]*/\u&/g'

The output:

Taco My-Fish-Tacos My_Fish_Tacos

The escaped lower case "u" capitalizes the next character in the matched sub-string.

Answer 2

Using awk:

echo 'test' | awk '{
     for ( i=1; i <= NF; i++) {
         sub(".", substr(toupper($i), 1,1) , $i);
         print $i;
         # or
         # print substr(toupper($i), 1,1) substr($i, 2);
     }
}'

Answer 3

Try the following:

sed 's/\([a-z]\)\([a-z]*\)/\U\1\L\2/g'

It works for me using GNU sed, but I don't think BSD sed supports \U and \L.