Simple grepper (text searcher)

#!/usr/bin/env python

#######################################################################
#
#   The following license supersedes all notices in the source code.
#
#   Copyright (c) 2021 Kurt Dekker/PLBM Games All rights reserved.
#
#   @kurtdekker - http://www.plbm.com
#
#   Redistribution and use in source and binary forms, with or without
#   modification, are permitted provided that the following conditions are
#   met:
#
#   Redistributions of source code must retain the above copyright notice,
#   this list of conditions and the following disclaimer.
#
#   Redistributions in binary form must reproduce the above copyright
#   notice, this list of conditions and the following disclaimer in the
#   documentation and/or other materials provided with the distribution.
#
#   Neither the name of the Kurt Dekker/PLBM Games nor the names of its
#   contributors may be used to endorse or promote products derived from
#   this software without specific prior written permission.
#
#   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
#   IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
#   TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
#   PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
#   HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
#   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
#   TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
#   PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
#   LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
#   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
#   SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
#####################################################################
#
# I cannot believe how irritating it is to search all *.TXT files in
# a posix environment, with huge clumsy find/for/grep combo chains.
#
# This is intended to make a nice simple way of doing things.
#
#####################################################################
#
import os, sys, fnmatch
from string import maketrans
import re

def main():
    argcopy = list(sys.argv[1:])

    option_showfile = 0         # put the file ON the same line
    option_fileonly = 0         # only display the filename
    option_matchcase = 0
    option_count = 0

    filepatterns = "*"

    if len(argcopy) < 2:
        print "Usage: %s [-f] [!]searchtext filepattern[,pattern2,pattern3]" % sys.argv[0]
        print " where ! will search for lines NOT containing searchtext"
        print " options: -f display filename"
        print " options: -l display filename only"
        print " options: -c count occurrences only"
        print " options: -m enforce correct case"
        print
        print "Example: (always escape wildcards on Posix systems)"
        print "$ grp kurt \*.txt"
        print "$ grp MyFunctionName \*.cs"
        exit()

    while len(argcopy[0]) > 1 and argcopy[0][0] == '-':
        if len(argcopy[0]) > 1:
            if argcopy[0][1] == 'f':
                option_showfile = 1
                print >> sys.stderr, "option_showfile enabled"

            if argcopy[0][1] == 'l':
                option_fileonly = 1
                print >> sys.stderr, "option_fileonly enabled"

            if argcopy[0][1] == 'c':
                option_count = 1
                option_fileonly = 1
                print >> sys.stderr, "option_count enabled"

            if argcopy[0][1] == 'm':
                option_matchcase = 1
                print >> sys.stderr, "option_matchcase enabled"

        argcopy = argcopy[1:]

    searchtext = argcopy[0]

    argcopy = argcopy[1:]

    invert = 0
    if len(searchtext) > 0:
        if searchtext[0] == '!':
            searchtext = searchtext[1:]
            invert = 1

    filepatterns = argcopy[0].lower()

    if (not option_matchcase):
        searchtext = searchtext.lower()

    matches = []
    for root, dirnames, filenames in os.walk('.'):
        fnpairs = [(a.lower(),a) for a in filenames]
        for filepattern in filepatterns.split( ","):
            files = [fo for (fl,fo) in fnpairs if fnmatch.fnmatch(fl, filepattern)]
            for n in xrange( len( files)):
                oneline = os.path.join(root, files[n])
                if ((oneline.find( ".hg") < 0) and
                    (oneline.find( ".git") < 0) and
                    (oneline.find( ".DS_Store") < 0) and
                    (oneline.find( ".DSStore") < 0) and
                    True):
                    matches.append(oneline)

    tabtospacett = maketrans( '\t', ' ')

    anyfoundatall = 0

    output = []

    reignorecaseflags = re.IGNORECASE
    if option_matchcase:
        reignorecaseflags = 0
    reflags = reignorecaseflags
    rematcher = re.compile( ".*" + searchtext + ".*", reflags)

    for fn in matches:
        didfilename = 0
        foundany = 0
        count = 0
        try:
            with open( fn) as fp:
                for oneline in [a[:-1] for a in fp.readlines()]:
                    foundmatch = oneline.lower().find( searchtext) >= 0

                    rematched = rematcher.match( oneline)
                    if rematched:
                        foundmatch = 1

                    if option_matchcase:
                        foundmatch = oneline.find( searchtext) >= 0

                    if invert:
                        foundmatch = not foundmatch

                    if foundmatch:
                        count += 1
                        foundany = 1
                        anyfoundatall = 1

                        if option_showfile or not didfilename:
                            didfilename = 1
                            output.append( "File: %s: " % fn)

                        if not option_fileonly:
                            while len(oneline) and (oneline[-1] in ('\n', '\r',)):
                                oneline = oneline[:-1]
                            output.append( oneline.translate(tabtospacett))
        except:
            print "Unable to open " + fn + " for reading..."

        if invert:
            if not foundany:
                output.append( "File: %s:" % fn)

        if option_count:
            if count > 0:
                output.append( "%u" % count)

    if not anyfoundatall:
        print >> sys.stderr, "Don't forget to quote glob chars on Posix shells."
    else:
        if option_fileonly:
            outout = sorted(output)

        for o in output:
            print o

if __name__ == "__main__":
    main()