# util.py - utility functions and platform specfic implementations
#
# Copyright 2005 K. Thananchayan <thananck@yahoo.com>
#
# This software may be used and distributed according to the terms
# of the GNU General Public License, incorporated herein by reference.
import os, errno
from demandload import *
demandload(globals(), "re")
def unique(g):
seen = {}
for f in g:
if f not in seen:
seen[f] = 1
yield f
class CommandError(Exception): pass
def always(fn): return True
def never(fn): return False
def globre(pat, head = '^', tail = '$'):
"convert a glob pattern into a regexp"
i, n = 0, len(pat)
res = ''
group = False
def peek(): return i < n and pat[i]
while i < n:
c = pat[i]
i = i+1
if c == '*':
if peek() == '*':
i += 1
res += '.*'
else:
res += '[^/]*'
elif c == '?':
res += '.'
elif c == '[':
j = i
if j < n and pat[j] in '!]':
j += 1
while j < n and pat[j] != ']':
j += 1
if j >= n:
res += '\\['
else:
stuff = pat[i:j].replace('\\','\\\\')
i = j + 1
if stuff[0] == '!':
stuff = '^' + stuff[1:]
elif stuff[0] == '^':
stuff = '\\' + stuff
res = '%s[%s]' % (res, stuff)
elif c == '{':
group = True
res += '(?:'
elif c == '}' and group:
res += ')'
group = False
elif c == ',' and group:
res += '|'
else:
res += re.escape(c)
return head + res + tail
_globchars = {'[': 1, '{': 1, '*': 1, '?': 1}
def matcher(cwd, names, inc, exc, head = ''):
def patlike(name):
for prefix in 're:', 'glob:', 'path:':
if name.startswith(prefix): return True
for c in name:
if c in _globchars: return True
def regex(name, tail):
'''convert a pattern into a regular expression'''
if name.startswith('re:'):
return name[3:]
elif name.startswith('path:'):
return '^' + re.escape(name[5:]) + '$'
elif name.startswith('glob:'):
return head + globre(name[5:], '', tail)
return head + globre(name, '', tail)
cwdsep = cwd + os.sep
def under(fn):
"""check if fn is under our cwd"""
return not cwd or fn.startswith(cwdsep)
def matchfn(pats, tail):
"""build a matching function from a set of patterns"""
if pats:
pat = '(?:%s)' % '|'.join([regex(p, tail) for p in pats])
if cwd:
pat = re.escape(cwdsep) + pat
return re.compile(pat).match
pats = filter(patlike, names)
files = [n for n in names if not patlike(n)]
if pats: plain = []
elif cwd: plain = [cwdsep + f for f in files]
else: plain = files
patmatch = matchfn(pats, '$')
filematch = matchfn(files, '(?:/|$)')
incmatch = matchfn(inc, '(?:/|$)') or under
excmatch = matchfn(exc, '(?:/|$)') or (lambda fn: False)
return plain, lambda fn: (incmatch(fn) and not excmatch(fn) and
(fn.endswith('/') or
(not pats and not files) or
(pats and patmatch(fn)) or
(files and filematch(fn))))
def system(cmd, errprefix=None):
"""execute a shell command that must succeed"""
rc = os.system(cmd)
if rc:
errmsg = "%s %s" % (os.path.basename(cmd.split(None, 1)[0]),
explain_exit(rc)[0])
if errprefix:
errmsg = "%s: %s" % (errprefix, errmsg)
raise CommandError(errmsg)
def rename(src, dst):
try:
os.rename(src, dst)
except:
os.unlink(dst)
os.rename(src, dst)
def copytree(src, dst, copyfile):
"""Copy a directory tree, files are copied using 'copyfile'."""
names = os.listdir(src)
os.mkdir(dst)
for name in names:
srcname = os.path.join(src, name)
dstname = os.path.join(dst, name)
if os.path.isdir(srcname):
copytree(srcname, dstname, copyfile)
elif os.path.isfile(srcname):
copyfile(srcname, dstname)
else:
raise IOError("Not a regular file: %r" % srcname)
def _makelock_file(info, pathname):
ld = os.open(pathname, os.O_CREAT | os.O_WRONLY | os.O_EXCL)
os.write(ld, info)
os.close(ld)
def _readlock_file(pathname):
return file(pathname).read()
# Platfor specific varients
if os.name == 'nt':
nulldev = 'NUL:'
def is_exec(f, last):
return last
def set_exec(f, mode):
pass
def pconvert(path):
return path.replace("\\", "/")
makelock = _makelock_file
readlock = _readlock_file
def explain_exit(code):
return "exited with status %d" % code, code
else:
nulldev = '/dev/null'
def is_exec(f, last):
return (os.stat(f).st_mode & 0100 != 0)
def set_exec(f, mode):
s = os.stat(f).st_mode
if (s & 0100 != 0) == mode:
return
if mode:
# Turn on +x for every +r bit when making a file executable
# and obey umask.
umask = os.umask(0)
os.umask(umask)
os.chmod(f, s | (s & 0444) >> 2 & ~umask)
else:
os.chmod(f, s & 0666)
def pconvert(path):
return path
def makelock(info, pathname):
try:
os.symlink(info, pathname)
except OSError, why:
if why.errno == errno.EEXIST:
raise
else:
_makelock_file(info, pathname)
def readlock(pathname):
try:
return os.readlink(pathname)
except OSError, why:
if why.errno == errno.EINVAL:
return _readlock_file(pathname)
else:
raise
def explain_exit(code):
"""return a 2-tuple (desc, code) describing a process's status"""
if os.WIFEXITED(code):
val = os.WEXITSTATUS(code)
return "exited with status %d" % val, val
elif os.WIFSIGNALED(code):
val = os.WTERMSIG(code)
return "killed by signal %d" % val, val
elif os.WIFSTOPPED(code):
val = os.STOPSIG(code)
return "stopped by signal %d" % val, val
raise ValueError("invalid exit code")