upper- to lower-case using sed

Question

I\'d like to change the following patterns:

getFoo_Bar

to:

getFoo_bar

(note the lower b)

Knowing

Answer 1

Somewhat shorter:

echo getFoo_Bar | sed 's/_\(.\)/_\L\1/'

Answer 2

To change getFoo_Bar to getFoo_bar using sed :

echo "getFoo_Bar" | sed 's/^\(.\{7\}\)\(.\)\(.*\)$/\1\l\2\3/'

The upper and lowercase letters are handled by :

• \U Makes all text to the right uppercase.
• \u makes only the first character to the right uppercase.
• \L Makes all text to the right lowercase.
• \l Makes only the first character to the right lower case. (Note its a lowercase letter L)

The example is just one method for pattern matching, just based on modifying a single chunk of text. Using the example, getFoo_BAr transforms to getFoo_bAr, note the A was not altered.

Answer 3

Shortest I can come up with:

echo getFoo_Bar | sed 's/_./\L&/'

Answer 4

echo getFoo_Bar | sed 's/[Bb]/\L&/g'

Answer 5

If you want to write everything in lowercase just after underscore, than this would work for you:

echo getFoo_Bar | gawk -F_ '{print tolower($2)}'

Answer 6

You can use perl for this one:

perl -pe 's/(get[A-Z][A-Za-z0-9]*)_([A-Z])/\1_\l\2/'

The \l is the trick here.

sed doesn't do upper/lowercase on matched groups.