How do I convert all hexadecimal numbers to decimal in Vim?

Explanation

When cleaning logs, protocol dumps, or generated code, you may need to normalize 0x... literals into decimal quickly. Vim's expression replacement (\=) can evaluate each match and compute a converted value inline. This avoids external scripts and keeps the transformation fully repeatable in-editor.

How it works

• :%s/.../.../g runs a global substitute over the whole buffer
• 0x\x\+ matches hexadecimal literals like 0x1A, 0xff, 0x10
• \= tells substitute to evaluate the replacement as Vimscript
• submatch(0) returns the full matched literal
• str2nr(..., 16) converts that match from base-16 to decimal text

Every hex match is replaced by its decimal equivalent in one pass.

Example

Input:

mask=0xff
offset=0x10
limit=0x1a

Run:

:%s/0x\x\+/\=str2nr(submatch(0), 16)/g

Output:

mask=255
offset=16
limit=26

Tips

• Restrict scope with a range, for example :'<,'>s/.../.../g for a visual selection.
• Add c flag (.../gc) if you want confirmation per match.
• Keep a macro or command-line history entry for repeated data-cleaning tasks.