Auto-indenting graphviz .dot file

Question

I am working on a long and complex architectural graph. The document indentation mixes tabs, spaces and indentation levels, which drives me crazy.

Is there a simple way to automatically indent graphviz .dot files in Linux environment?

A pure command line tool would be best, but plugins to popular editors like vim would be a good solution too.

Update:

The vim indentation has a bug with : in node names in edges. For example, server_a:event -> log_server; causes the next line to be further indented, presumably because the : is parsed as a block declaration (see comments on Harry Pehkonen's answer). Quoting the node name (e.g. "server_a":event -> log_server;) solves this issue:

#!/usr/bin/python3

import re

dot=open('components.dot').read()
reg=re.compile("(\s)(\S+)(\:.*\-\>)")
print(reg.sub(r'\1"\2"\3', dot))

Answer 1

Vim has dot syntax knowledge out of the box, and seems to re-indent dot files for me.

I removed all indentation, went to the top of the file, and did =G

Your global tab-related values determine whether to use tabs/spaces, how many, etc.

If you want, you can create a script with:

> vim -W reIndentAndSave whatever.dot

Edit your dot file by re-indenting from top with

gg=G

...Save

:x

Then, for each file you want to re-indent via the script that you just recorded,

> vim -s reIndentAndSave somegraph.dot

Answer 2

On emacs, if the buffer has a mode that supports indentation, you can reindent a whole buffer like this: C-x h to select all buffer then indent-region.

It's interactive not scripted, but it works.

If your emacs that has graphviz-dot-mode, you can give it a try.

Yet I'm not fully satisfied by the result in this particular mode since it tends to not get closing braces aligned with opening braces (at least with graphviz-dot-mode.el Version 0.3.6 dates 19/02/2011).