First checkin of real Distutils code.

Lib/distutils/util.py

@@ -0,0 +1,245 @@
+"""distutils.util
+
+General-purpose utility functions used throughout the Distutils
+(especially in command classes).  Mostly filesystem manipulation, but
+not limited to that.  The functions in this module generally raise
+DistutilsFileError when they have problems with the filesystem, because
+os.error in pre-1.5.2 Python only gives the error message and not the
+file causing it."""
+
+# created 1999/03/08, Greg Ward
+
+__rcsid__ = "$Id$"
+
+import os
+from distutils.errors import *
+
+
+# I don't use os.makedirs because a) it's new to Python 1.5.2, and
+# b) it blows up if the directory already exists (I want to silently
+# succeed in that case).
+def mkpath (name, mode=0777, verbose=0):
+    """Create a directory and any missing ancestor directories.  If the
+       directory already exists, return silently.  Raise
+       DistutilsFileError if unable to create some directory along the
+       way (eg. some sub-path exists, but is a file rather than a
+       directory).  If 'verbose' is true, print a one-line summary of
+       each mkdir to stdout."""
+
+    # XXX what's the better way to handle verbosity? print as we create
+    # each directory in the path (the current behaviour), or only announce
+    # the creation of the whole path, and force verbose=0 on all sub-calls?
+
+    if os.path.isdir (name):
+        return
+
+    (head, tail) = os.path.split (name)
+    tails = [tail]                      # stack of lone dirs to create
+    
+    while head and tail and not os.path.isdir (head):
+        #print "splitting '%s': " % head,
+        (head, tail) = os.path.split (head)
+        #print "to ('%s','%s')" % (head, tail)
+        tails.insert (0, tail)          # push next higher dir onto stack
+
+    #print "stack of tails:", tails
+
+    # now 'head' contains the highest directory that already exists
+    for d in tails:
+        #print "head = %s, d = %s: " % (head, d),
+        head = os.path.join (head, d)
+        if verbose:
+            print "creating", head
+        try:
+            os.mkdir (head)
+        except os.error, (errno, errstr):
+            raise DistutilsFileError, "%s: %s" % (head, errstr)
+
+# mkpath ()
+
+
+def newer (file1, file2):
+    """Return true if file1 exists and is more recently modified than
+       file2, or if file1 exists and file2 doesn't.  Return false if both
+       exist and file2 is the same age or younger than file1.  Raises
+       DistutilsFileError if file1 does not exist."""
+
+    if not os.path.exists (file1):
+        raise DistutilsFileError, "file '%s' does not exist" % file1
+    if not os.path.exists (file2):
+        return 1
+
+    from stat import *
+    mtime1 = os.stat(file1)[ST_MTIME]
+    mtime2 = os.stat(file2)[ST_MTIME]
+
+    return mtime1 > mtime2
+
+# newer ()
+
+
+def make_file (src, dst, func, args,
+               verbose=0, update_message=None, noupdate_message=None):
+    """Makes 'dst' from 'src' (both filenames) by calling 'func' with
+       'args', but only if it needs to: i.e. if 'dst' does not exist or
+       'src' is newer than 'dst'."""
+
+    if newer (src, dst):
+        if verbose and update_message:
+            print update_message
+        apply (func, args)
+    else:
+        if verbose and noupdate_message:
+            print noupdate_message
+
+# make_file ()
+
+
+def _copy_file_contents (src, dst, buffer_size=16*1024):
+    """Copy the file 'src' to 'dst'; both must be filenames.  Any error
+       opening either file, reading from 'src', or writing to 'dst',
+       raises DistutilsFileError.  Data is read/written in chunks of
+       'buffer_size' bytes (default 16k).  No attempt is made to handle
+       anything apart from regular files."""
+
+    # Stolen from shutil module in the standard library, but with
+    # custom error-handling added.
+
+    fsrc = None
+    fdst = None
+    try:
+        try:
+            fsrc = open(src, 'rb')
+        except os.error, (errno, errstr):
+            raise DistutilsFileError, "could not open %s: %s" % (src, errstr)
+        
+        try:
+            fdst = open(dst, 'wb')
+        except os.error, (errno, errstr):
+            raise DistutilsFileError, "could not create %s: %s" % (dst, errstr)
+        
+        while 1:
+            try:
+                buf = fsrc.read (buffer_size)
+            except os.error, (errno, errstr):
+                raise DistutilsFileError, \
+                      "could not read from %s: %s" % (src, errstr)
+            
+            if not buf:
+                break
+
+            try:
+                fdst.write(buf)
+            except os.error, (errno, errstr):
+                raise DistutilsFileError, \
+                      "could not write to %s: %s" % (dst, errstr)
+            
+    finally:
+        if fdst:
+            fdst.close()
+        if fsrc:
+            fsrc.close()
+
+# _copy_file_contents()
+
+
+def copy_file (src, dst,
+               preserve_mode=1,
+               preserve_times=1,
+               update=0,
+               verbose=0):
+
+    """Copy a file 'src' to 'dst'.  If 'dst' is a directory, then 'src'
+       is copied there with the same name; otherwise, it must be a
+       filename.  (If the file exists, it will be ruthlessly clobbered.)
+       If 'preserve_mode' is true (the default), the file's mode (type
+       and permission bits, or whatever is analogous on the current
+       platform) is copied.  If 'preserve_times' is true (the default),
+       the last-modified and last-access times are copied as well.  If
+       'update' is true, 'src' will only be copied if 'dst' does not
+       exist, or if 'dst' does exist but is older than 'src'.  If
+       'verbose' is true, then a one-line summary of the copy will be
+       printed to stdout."""
+
+    # XXX doesn't copy Mac-specific metadata
+       
+    from shutil import copyfile
+    from stat import *
+
+    if not os.path.isfile (src):
+        raise DistutilsFileError, \
+              "can't copy %s:not a regular file" % src
+
+    if os.path.isdir (dst):
+        dir = dst
+        dst = os.path.join (dst, os.path.basename (src))
+    else:
+        dir = os.path.dirname (dst)
+
+    if update and not newer (src, dst):
+        return
+
+    if verbose:
+        print "copying %s -> %s" % (src, dir)
+
+    copyfile (src, dst)
+    if preserve_mode or preserve_times:
+        st = os.stat (src)
+        if preserve_mode:
+            os.chmod (dst, S_IMODE (st[ST_MODE]))
+        if preserve_times:
+            os.utime (dst, (st[ST_ATIME], st[ST_MTIME]))
+
+# copy_file ()
+
+
+def copy_tree (src, dst,
+               preserve_mode=1,
+               preserve_times=1,
+               preserve_symlinks=0,
+               update=0,
+               verbose=0):               
+
+    """Copy an entire directory tree 'src' to a new location 'dst'.  Both
+       'src' and 'dst' must be directory names.  If 'src' is not a
+       directory, raise DistutilsFileError.  If 'dst' does not exist, it
+       is created with 'mkpath'.  The endresult of the copy is that
+       every file in 'src' is copied to 'dst', and directories under
+       'src' are recursively copied to 'dst'.
+
+       'preserve_mode' and 'preserve_times' are the same as for
+       'copy_file'; note that they only apply to regular files, not to
+       directories.  If 'preserve_symlinks' is true, symlinks will be
+       copied as symlinks (on platforms that support them!); otherwise
+       (the default), the destination of the symlink will be copied.
+       'update' and 'verbose' are the same as for 'copy_file'."""
+
+    if not os.path.isdir (src):
+        raise DistutilsFileError, \
+              "cannot copy tree %s: not a directory" % src    
+    try:
+        names = os.listdir (src)
+    except os.error, (errno, errstr):
+        raise DistutilsFileError, \
+              "error listing files in %s: %s" % (src, errstr)
+
+        
+    mkpath (dst, verbose=verbose)
+
+    for n in names:
+        src_name = os.path.join (src, n)
+        dst_name = os.path.join (dst, n)
+
+        if preserve_symlinks and os.path.islink (src_name):
+            link_dest = os.readlink (src_name)
+            os.symlink (link_dest, dst_name)
+        elif os.path.isdir (src_name):
+            copy_tree (src_name, dst_name,
+                       preserve_mode, preserve_times, preserve_symlinks,
+                       update, verbose)
+        else:
+            copy_file (src_name, dst_name,
+                       preserve_mode, preserve_times,
+                       update, verbose)
+
+# copy_tree ()