Check for a modern version of sndfile in configure scripts (bug #44976). * configure.ac: Call OCTAVE_CHECK_LIB_SNDFILE_OK after first determining that sndfile library exists. * m4/acinclude.m4 (OCTAVE_CHECK_LIB_SNDFILE_OK): New macro to check for a modern version of lib sndfile with Ogg support.

#!/bin/sh
#
# Like mv $1 $2, but if the files are the same, just delete $1.
# Status is 0 if $2 is changed, 1 otherwise.

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