No need to fatal () on startup if $PWD doesn't exist; chdir to "/" instead. src/ChangeLog addition: 2009-11-08 Aidan Kehoe <kehoea@parhasard.net> * sysfile.h (DEFAULT_DIRECTORY_FALLBACK): New #define, "/" on Unix and "C:\\" on Win32 native, a directory that should "always" be available. * fileio.c (Fexpand_file_name): Use DEFAULT_DIRECTORY_FALLBACK here, instead of conditionalising on WIN32_NATIVE. * editfns.c (get_home_directory): Use DEFAULT_DIRECTORY_FALLBACK if looking up the home directory fails, on both Windows and Unix. * buffer.c (init_initial_directory): Don't give a fatal error if the current directory doesn't exist, chdir to DEFAULT_DIRECTORY_FALLBACK instead.

#!/bin/sh
if
test -r $2
then
if
cmp $1 $2 > /dev/null
then
echo $2 is unchanged
rm -f $1
else
mv -f $1 $2
fi
else
mv -f $1 $2
fi