Re: cp -up forever

[Dan Jacobson]

Here on debian sid coreutils 5.2.1-2 we see back digits are not tended to:
# touch -r m o
# stat -c %y m o
2004-10-10 01:56:36.561517778 +0800
2004-10-10 01:56:36.561517000 +0800
which must be the key to why cp -up will update repeatedly.

Some lines from the strace you wanted:
fstat64(4, {st_dev=makedev(3, 73), st_ino=22543, st_mode=S_IFREG|0644, 
st_nlink=1, st_uid=1000, st_gid=1000, st_blksize=4096, st_blocks=0, st_size=0, 
st_atime=2004/10/10-01:35:41, st_mtime=2004/10/10-01:35:51, 
st_ctime=2004/10/10-01:35:51}) = 0
fstat64(3, {st_dev=makedev(3, 73), st_ino=22526, st_mode=S_IFREG|0644, 
st_nlink=1, st_uid=1000, st_gid=1000, st_blksize=4096, st_blocks=0, st_size=0, 
st_atime=2004/10/10-01:35:46, st_mtime=2004/10/10-01:35:31, 
st_ctime=2004/10/10-01:35:31}) = 0
utimes("h", {1097343346, 622999})       = 0
getxattr("g", "system.posix_acl_access", 0xbffff4e0, 132) = -1 EOPNOTSUPP 
(Operation not supported)
setxattr("h", "system.posix_acl_access", 
"\x02\x00\x00\x00\x01\x00\x06\x00\xff\xff\xff\xff\x04\x00\x04\x00\xff\xff\xff\xff
 \x00\x04\x00\xff\xff\xff\xff", 28, ) = -1 EOPNOTSUPP (Operation not supported)

P.S. in your docs,
  In a few cases, the GNU utilities' default behavior is incompatible
  with the POSIX standard.  To suppress these incompatibilities, define
  the `POSIXLY_CORRECT' environment variable.
Well, say there how we shall do that. I.e., if all POSIXLY_CORRECT= or
POSIXLY_CORRECT=0 or POSIXLY_CORRECT=1 or POSIXLY_CORRECT="" are
kosher.  BTW, setting it didn't affect cp here.