~bzr-pqm/bzr/bzr.dev

# Bazaar-NG -- distributed version control

# Copyright (C) 2005 by Canonical Ltd

# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.

# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.

# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

import os, types, re, time, types
from stat import S_ISREG, S_ISDIR, S_ISLNK, ST_MODE, ST_SIZE

from errors import bailout

def make_readonly(filename):
    """Make a filename read-only."""
    # TODO: probably needs to be fixed for windows
    mod = os.stat(filename).st_mode
    mod = mod & 0777555
    os.chmod(filename, mod)


def make_writable(filename):
    mod = os.stat(filename).st_mode
    mod = mod | 0200
    os.chmod(filename, mod)


_QUOTE_RE = re.compile(r'([^a-zA-Z0-9.,:/_~-])')
def quotefn(f):
    """Return shell-quoted filename"""
    ## We could be a bit more terse by using double-quotes etc
    f = _QUOTE_RE.sub(r'\\\1', f)
    if f[0] == '~':
        f[0:1] = r'\~' 
    return f


def file_kind(f):
    mode = os.lstat(f)[ST_MODE]
    if S_ISREG(mode):
        return 'file'
    elif S_ISDIR(mode):
        return 'directory'
    elif S_ISLNK(mode):
        return 'symlink'
    else:
        bailout("can't handle file kind with mode %o of %r" % (mode, f)) 



def isdir(f):
    """True if f is an accessible directory."""
    try:
        return S_ISDIR(os.lstat(f)[ST_MODE])
    except OSError:
        return False



def isfile(f):
    """True if f is a regular file."""
    try:
        return S_ISREG(os.lstat(f)[ST_MODE])
    except OSError:
        return False


def pumpfile(fromfile, tofile):
    """Copy contents of one file to another."""
    tofile.write(fromfile.read())


def uuid():
    """Return a new UUID"""
    
    ## XXX: Could alternatively read /proc/sys/kernel/random/uuid on
    ## Linux, but we need something portable for other systems;
    ## preferably an implementation in Python.
    try:
        return chomp(file('/proc/sys/kernel/random/uuid').readline())
    except IOError:
        return chomp(os.popen('uuidgen').readline())


def chomp(s):
    if s and (s[-1] == '\n'):
        return s[:-1]
    else:
        return s


def sha_file(f):
    import sha
    ## TODO: Maybe read in chunks to handle big files
    if hasattr(f, 'tell'):
        assert f.tell() == 0
    s = sha.new()
    s.update(f.read())
    return s.hexdigest()


def sha_string(f):
    import sha
    s = sha.new()
    s.update(f)
    return s.hexdigest()



def fingerprint_file(f):
    import sha
    s = sha.new()
    b = f.read()
    s.update(b)
    size = len(b)
    f.close()
    return {'size': size,
            'sha1': s.hexdigest()}



def username():
    """Return email-style username.

    Something similar to 'Martin Pool <mbp@sourcefrog.net>'

    :todo: Check it's reasonably well-formed.

    :todo: Allow taking it from a dotfile to help people on windows
           who can't easily set variables.

    :todo: Cope without pwd module, which is only on unix. 
    """
    e = os.environ.get('BZREMAIL') or os.environ.get('EMAIL')
    if e: return e

    import socket
    
    try:
        import pwd
        uid = os.getuid()
        w = pwd.getpwuid(uid)
        gecos = w.pw_gecos
        comma = gecos.find(',')
        if comma == -1:
            realname = gecos
        else:
            realname = gecos[:comma]
        return '%s <%s@%s>' % (realname, w.pw_name, socket.getfqdn())
    except ImportError:
        pass

    import getpass, socket
    return '<%s@%s>' % (getpass.getuser(), socket.getfqdn())


def user_email():
    """Return just the email component of a username."""
    e = os.environ.get('BZREMAIL') or os.environ.get('EMAIL')
    if e:
        import re
        m = re.search(r'[\w+.-]+@[\w+.-]+', e)
        if not m:
            bailout('%r is not a reasonable email address' % e)
        return m.group(0)


    import getpass, socket
    return '%s@%s' % (getpass.getuser(), socket.getfqdn())

    


def compare_files(a, b):
    """Returns true if equal in contents"""
    # TODO: don't read the whole thing in one go.
    BUFSIZE = 4096
    while True:
        ai = a.read(BUFSIZE)
        bi = b.read(BUFSIZE)
        if ai != bi:
            return False
        if ai == '':
            return True



def local_time_offset(t=None):
    """Return offset of local zone from GMT, either at present or at time t."""
    # python2.3 localtime() can't take None
    if t is None:
        t = time.time()
        
    if time.localtime(t).tm_isdst and time.daylight:
        return -time.altzone
    else:
        return -time.timezone

    
def format_date(t, offset=0, timezone='original'):
    ## TODO: Perhaps a global option to use either universal or local time?
    ## Or perhaps just let people set $TZ?
    import time
    
    assert isinstance(t, float)
    
    if timezone == 'utc':
        tt = time.gmtime(t)
        offset = 0
    elif timezone == 'original':
        if offset == None:
            offset = 0
        tt = time.gmtime(t + offset)
    elif timezone == 'local':
        tt = time.localtime(t)
        offset = local_time_offset(t)
    else:
        bailout("unsupported timezone format %r",
                ['options are "utc", "original", "local"'])

    return (time.strftime("%a %Y-%m-%d %H:%M:%S", tt)
            + ' %+03d%02d' % (offset / 3600, (offset / 60) % 60))


def compact_date(when):
    return time.strftime('%Y%m%d%H%M%S', time.gmtime(when))
    


def filesize(f):
    """Return size of given open file."""
    return os.fstat(f.fileno())[ST_SIZE]


if hasattr(os, 'urandom'): # python 2.4 and later
    rand_bytes = os.urandom
else:
    # FIXME: No good on non-Linux
    _rand_file = file('/dev/urandom', 'rb')
    rand_bytes = _rand_file.read


## TODO: We could later have path objects that remember their list
## decomposition (might be too tricksy though.)

def splitpath(p):
    """Turn string into list of parts.

    >>> splitpath('a')
    ['a']
    >>> splitpath('a/b')
    ['a', 'b']
    >>> splitpath('a/./b')
    ['a', 'b']
    >>> splitpath('a/.b')
    ['a', '.b']
    >>> splitpath('a/../b')
    Traceback (most recent call last):
    ...
    BzrError: ("sorry, '..' not allowed in path", [])
    """
    assert isinstance(p, types.StringTypes)
    ps = [f for f in p.split('/') if f != '.']
    for f in ps:
        if f == '..':
            bailout("sorry, %r not allowed in path" % f)
    return ps

def joinpath(p):
    assert isinstance(p, list)
    for f in p:
        if (f == '..') or (f is None) or (f == ''):
            bailout("sorry, %r not allowed in path" % f)
    return '/'.join(p)


def appendpath(p1, p2):
    if p1 == '':
        return p2
    else:
        return p1 + '/' + p2
    

def extern_command(cmd, ignore_errors = False):
    mutter('external command: %s' % `cmd`)
    if os.system(cmd):
        if not ignore_errors:
            bailout('command failed')