, :
~/.hgrc(UNIX/Mac) c:\users [ ]\mercurial.ini,
[extensions]
extdiff=
[extdiff]
cmd.vdiff = opendiff
cmd.kdiff = kdiff3
hg vdiff filename
hg kdiff filename
opendiff kdiff3 , , , .
cmd.echo = echo
, 2 ,
hg echo filename
hg echo -r -2 filename <-- you will see different filenames if that revision exists