langgrep

#! /usr/bin/env python

# langgrep: grep for a pattern but only in files written in the
# specified language (as specified by the shebang line).
#
# Copyright 2009 by Akkana Peck.
# Please share, modify and enjoy under the terms of the GPL v2
# or, at your option, any later GPL version.
#
# Bugs: it isn't smart about parsing the grep flags.
# Anything beginning with a - will be considered a flag
# and passed on to grep; the first argument not starting with -
# is taken to be the search pattern, and everything after that
# is the file list.
#

import string, os, sys
import subprocess
import shlex

def Usage():
    print("langgrep lang [grepflags] pattern files")
    print(" e.g. langgrep python -w find *")
    sys.exit(0)

def check_file_lang(filename, lang):
    if lang.startswith("python") and filename.endswith(".py"):
        return True
    if os.path.isdir(filename) or not os.path.exists(filename):
        return False
    try:
        f = open(filename, 'rb')
        firstline = f.readline()
        f.close()
    except IOError as e:
        print("IOError", e)
        #print "exc_info is", sys.exc_info()
        sys.exit(1)
        return False

    if firstline[0:2] == "#!" and firstline.find(lang) >= 0:
        return True
    return False

# main()
if len(sys.argv) < 3:
    Usage()
lang = sys.argv[1]

# After the language, any flag argument plus the grep pattern
# gets appended to args -- these will be the grep args.
patindex = 0
for i in range(2, len(sys.argv)):
    if sys.argv[i][0] != '-':
        patindex = i+1
        break
args = sys.argv[2:patindex]

# Now args are the arguments passed to grep;
# the file list, if any, is sys.argv[patindex+1:]
# If no file list, use ~/bin/*
if patindex >= len(sys.argv):
    files = set()

    # Look nonrecursively at ~/bin/*
    bindir = os.path.join(os.getenv("HOME"), "bin")
    for f in os.listdir(bindir):
        files.add(os.path.join(bindir, f))

    # If language is python, also look in $PYTHONPATH, recursively.
    if lang == "python":
        pypathdir = os.path.join(bindir, "pythonpath")
        if os.path.exists(pypathdir):
            for root, dirs, fs in os.walk(pypathdir, followlinks=True):
                for f in fs:
                    if f.endswith(".py"):
                        files.add(os.path.join(root, f))

else:
    files = sys.argv[patindex:]

try:
    filelist = list(files)
    filelist.sort()
    for fil in filelist:
        if check_file_lang(fil, lang):
            arglist = ['grep', '-H']
            arglist.extend(args)
            arglist.append(fil)
            proc = subprocess.Popen(arglist,
                                    shell=False, stdout=subprocess.PIPE)
            pout = proc.communicate()[0]

            # Go through the output removing all but the last dir of the path.
            # Otherwise lines are so long they're confusing.
            if not pout:
                continue
            for line in pout.decode("utf-8").split('\n'):
                # For some reason the split is giving us every other line empty
                if not line:
                    continue
                colon = line.find(":")
                pathparts = line[:colon].split('/')
                if len(pathparts) < 2 or pathparts[-2] == "bin":
                    path = pathparts[-1]
                else:
                    path = '/'.join(pathparts[-2:])
                s = "%s%s" % (path, line[colon:])
                print(s.encode('utf-8', "backslashreplace"))

# Try to catch ctrl-C and print a nicer message. This doesn't work, though:
# subprocess.call just terminates the whole process.
except KeyboardInterrupt as e:
    print("Interrupt!")
    sys.exit(1)