Recursively Traverse Directory And Replace Function Calls

I would like to traverse a directory recursively and find all files that have at least one of the function calls of the following set: A(a) B(a,b) C(a,b,c) now, disregarding the a

Solution 1:

This uses os.walk to traverse all files recursively (starting from the current working directory).

The backup='_bak' argument tells fileinput.input to make a backup of each file.

import os
import sys
import re
import fileinput

defsub_callback(match):
    func,args=match.groups()
    fargs=','.join('f({a})'.format(a=a) for a in args.split(','))
    return ('''\
#if def LOL
    {func}_new({fa})        
#else
    {func}({a})
#endif
'''.format(func=func,a=args,fa=fargs))

for root, dirs, files in os.walk('.'):
    for line in fileinput.input(
        (os.path.join(root,name) for name in files),
        inplace=True,
        backup='_bak'
        ):
        line=re.sub(r'\b([A-C])\((.*?)\)',sub_callback,line)
        sys.stdout.write(line)

Solution 2:

find -type f -exec perl -i.bak -pe'
   if (my ($orig, $pre, $func, $args, $post) =/^((.*)\b(A|B|C)\((.*?)\)(.*?))\n/s
   ) {
       $args= join ', ', map { "f($_)" } split /,\s*/, $args;
       $_="#ifdef LOL\n";
       $_.=$pre${func}_new($args)$post\n";
       $_ .= "#else\n";
       $_ .= $orig\n";
       $_.="#endif\n";
   }
' {} +

Makes a lot of assumptions. Let me know if one of them produces too many problems.