In /usr/bin/ps2ps line 7:
gs="`dirname \"$0\"`/$GS_EXECUTABLE"
    ^--------------^ SC2006: Use $(...) notation instead of legacy backticked `...`.

Did you mean: 
gs="$(dirname \"$0\")/$GS_EXECUTABLE"


In /usr/bin/ps2ps line 24:
	echo "Usage: `basename \"$0\"` [options] input.ps output.ps" 1>&2
                     ^---------------^ SC2006: Use $(...) notation instead of legacy backticked `...`.

Did you mean: 
	echo "Usage: $(basename \"$0\") [options] input.ps output.ps" 1>&2


In /usr/bin/ps2ps line 25:
	echo "  e.g. `basename \"$0\"` -sPAPERSIZE=a4 input.ps output.ps" 1>&2
                     ^---------------^ SC2006: Use $(...) notation instead of legacy backticked `...`.

Did you mean: 
	echo "  e.g. $(basename \"$0\") -sPAPERSIZE=a4 input.ps output.ps" 1>&2


In /usr/bin/ps2ps line 29:
exec "$GS_EXECUTABLE" -q -sDEVICE=ps2write -sstdout=%stderr "-sOutputFile=$2" -dNOPAUSE -dBATCH $OPTIONS "$1"
                                                                                                ^------^ SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
exec "$GS_EXECUTABLE" -q -sDEVICE=ps2write -sstdout=%stderr "-sOutputFile=$2" -dNOPAUSE -dBATCH "$OPTIONS" "$1"

For more information:
  https://www.shellcheck.net/wiki/SC2086 -- Double quote to prevent globbing ...
  https://www.shellcheck.net/wiki/SC2006 -- Use $(...) notation instead of le...