rootls -- list the contents of ROOT files from the terminal

#! /usr/bin/env python

"""\
Usage: %prog <rootfile>

List the contents of a ROOT file, and their types.
The format can be controlled a bit -- see the options.

TODO:
  * Add regex path filtering
"""

## Set up argument parser
import optparse, sys
op = optparse.OptionParser(usage=__doc__)
fchoices = "fancy|plain|minimal"
op.add_option("-f", "--format", dest="FORMAT", type="choice", choices=fchoices.split("|"),
              help="choose the printout format from %s (default: %%default)" % fchoices, default="fancy")

## Handle arguments
opts, args = op.parse_args()
try:
    fname = args[0]
except:
    op.print_usage()
    sys.exit(1)



import ROOT
ROOT.gROOT.SetBatch(True)

def fancylistall(d, indent=""):
    "Print out all contents of a "
    for key in d.GetListOfKeys():
        kname = key.GetName()
        if key.IsFolder():
            print indent+"D", kname
            fancylistall(d.Get(kname), indent+"  ")
        else:
            print "%s%s %s" % (indent, d.Get(kname).ClassName(), kname)

def getall(d, basepath="/"):
    for key in d.GetListOfKeys():
        kname = key.GetName()
        if key.IsFolder():
            # TODO: -> "yield from" in Py3
            for i in getall(d.Get(kname), basepath+kname+"/"):
                yield i
        else:
            yield basepath+kname, d.Get(kname)



## Loop over the file contents
f = ROOT.TFile(fname)
print "Listing for ROOT file '%s':\n" % fname
if opts.FORMAT == "fancy":
    fancylistall(f)
else:
    for k, o in getall(f):
        t = o.ClassName()+"  " if opts.FORMAT != "minimal" else ""
        print t+k