Question

Could you help me with a regex to change lines like

<string name="Final time">Final time</string>
<string name="After extra time">After extra time</string>

to lines

<string name="final_time">Final time</string>
<string name="after_extra_time">After extra time</string>

So between double quotations replace space with underscore and make all letters lowercase.

I will use this regex with search/replace in VIM.

Answer 1

A generic approach:

:%s/\(<string name="\)\(\u\)\([^" ]\+\) \([^" ]\+\)/\1\l\2\e\3_\4/

This replaces every string @name that

• starts with an upper case character (\u) and
• consists of two space-separated words (\([^" ]\+\) \([^" ]\+\)) and
• replaces it with the corresponding lower-case character (\l\2\e).
• It also replaces the space with an underscore.

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To make everything in @name lower-case, this could be simplified:

:%s/\(<string name="\)\([^" ]\+\) \([^" ]\+\)/\1\l\2_\3_\e/

---

To get rid of multiple spaces, do two steps. First, make the attribute value lower-case:

:%s/\(<string name="\)\([^"]\+\)/\1\l\2\e/

then, replace every space in the attribute value with an underscore

:%s/\(<string name="[^"]*\)\@<= /_/g

Note that the \@<= is vim’s way of expressing a positive look-behind assertion.