CacheClean

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Revision as of 21:10, 22 November 2011 by Graysky (Talk | contribs) (now handles .sig files as well / thanks to ellak https://bbs.archlinux.org/viewtopic.php?id=130184)

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This script has been included in the AUR at this page.

It was originally written by "alterkacker" - see his forum thread: A utility for cleaning /var/cache/pacman/pkg


#!/usr/bin/env python
"""cache_clean - a simple python script to clean up the /var/cache/pacman/pkg directory.
More versatile than 'pacman -Sc' in that you can select how many old versions
to keep.
Usage: cache_clean {-p} {-v} <# of copies to keep>
	# of copies to keep - (required) how many generations of each package to keep
	-p - (optional) preview what would be deleted; forces verbose (-v) mode.
	-v - (optional) show deleted packages."""

# Note that the determination of package age is done by simply looking at the date-time
# modified stamp on the file. There is just enough variation in the way package version
# is done that I thought this would be simpler & just as good.
# Also note that you must be root to run this script.

import getopt
import os
import re
import sys

# helper function to get tuple of (file dtm, file name, file sz)    
def fn_stats(fn):
	s = os.stat(fn)
	return (s[8], fn, s[6])

# cleanup does the actual pkg file deletion
def cleanup(run_list):
	# strictly speaking only the first two of these globals need to be listed.
	global n_deleted, bytes_deleted, opt_verbose, opt_preview, n_to_keep
	# return if the run_list is too short
	#print run_list
	#return
	if len(run_list) <= n_to_keep: return
	# Build list of tuples (date-time file modified, file name, file size)
	dtm_list = [fn_stats(tfn) for tfn in run_list]
	# Sort the list by date-time
	dtm_list.sort()
	# Build list of the filenames to delete (all but last n_to_keep).
	# <showing_off>
	#kill_list = [tfn[1] for tfn in dtm_list[:-n_to_keep]]
	#bytes_deleted = sum(x[2] for x in dtm_list[:-n_to_keep])
	# </showing_off>
	kill_list = []
	for x in dtm_list[:-n_to_keep]:
		if os.path.isfile(x[1]):
			kill_list.append(x[1])
			bytes_deleted += x[2]
	if opt_verbose and kill_list: print (kill_list)
	n_deleted += len(kill_list)
	# and finally delete (if not in preview mode)
	if not opt_preview:
		for dfn in kill_list:
			os.unlink(dfn)

######################################################################
# mainline processing

# process command line options
try:
	opts, pargs = getopt.getopt(sys.argv[1:], 'vp')
	opt_dict = dict(opts)
	opt_preview = '-p' in opt_dict
	opt_verbose = '-v' in opt_dict
	if opt_preview: opt_verbose = True
	if len(pargs) == 1:
		n_to_keep = pargs[0]
	else:
		raise getopt.GetoptError("missing required argument.")
	try:
		n_to_keep = int(n_to_keep)
		if n_to_keep <= 0: raise ValueError
	except ValueError as e:
		raise getopt.GetoptError("# of copies to keep must be numeric > 0!")
except getopt.GetoptError as msg:
	print ("Error:",msg,"\n",__doc__)
	sys.exit(1)

# change to the pkg directory & get a sorted list of its contents
os.chdir('/var/cache/pacman/pkg')
pkg_fns = os.listdir('.')
pkg_fns.sort()

# Pattern to use to extract the package name from the tar file name:
# for pkg e.g. 'gnome-common-2.8.0-1-i686.pkg.tar.gz' group(1) is 'gnome-common'.

bpat = re.compile("""
^([^-/][^/]*?)-         # (1) package name
[^-/\s]+-               # (2) version
[^-/\s]+                # (3) release
(-i686|-x86_64|-any)?   # (4) architecture
\.pkg\.tar              # (5) extension
(?:\.(?:gz|bz2|xz|Z))?  # (6) compresssion extension
(?:\.aria2|.sig)?$      # (7) other extension
""", re.X)

n_deleted = 0
bytes_deleted = 0
pkg_base_nm = ''
# now look for "runs" of the same package name differing only in version info.
for run_end in range(len(pkg_fns)):
	fn = pkg_fns[run_end]

	# make sure we skip directories
	if os.path.isfile(fn):
		mo = bpat.match(fn) # test for a match of the package name pattern
		if mo:
			# print ("Processing file '" + fn + "' " + str(mo.lastindex), file=sys.stdout)
			tbase = mo.group(1) # gets the 'base' package name
			# include the architecture in the name if it's present
			if mo.group(2) is not None:
				tbase += mo.group(2)
			# print ('tbase: ' + tbase + '  ' + str(mo.lastindex), file=sys.stdout)
			# is it a new base name, i.e. the start of a new run?
			if tbase != pkg_base_nm: # if so then process the prior run
				if pkg_base_nm != '':
					cleanup(pkg_fns[run_start:run_end])
				pkg_base_nm = tbase # & setup for the new run
				run_start = run_end
		else:
			print ("File '"+fn+"' doesn't match package pattern!", file=sys.stderr)
	else:
		print ("skipping directory '" + fn + "'!", file=sys.stdout)

# catch the final run of the list
run_end += 1
cleanup(pkg_fns[run_start:run_end])

if opt_verbose:
	if opt_preview:
		print ("Preview mode (no files deleted):"),
	print ("{} files deleted, {:.3f} kBytes / {:.3f} MBytes / {:.3f} GBytes".
		format(n_deleted, bytes_deleted/(2**10), bytes_deleted/(2**20), bytes_deleted/(2**30)))