Bug 912902: basename not guaranteed to work for Shell tools

bin/pt-sift

@@ -1,5 +1,7 @@
 #!/usr/bin/env bash
 
+TOOL="pt-sift"
+
 # This program is part of Percona Toolkit: http://www.percona.com/software/
 # See "COPYRIGHT, LICENSE, AND WARRANTY" at the end of this file for legal
 # notices and disclaimers.
@@ -536,7 +538,8 @@ main() {
 
 # Execute the program if it was not included from another file.  This makes it
 # possible to include without executing, and thus test.
-if [ "$(basename "$0")" = "pt-sift" ] || [ "$(basename "$0")" = "bash" -a "$_" = "$0" ]; then
+if    [ "${0##*/}" = "$TOOL" ] \
+   || [ "${0##*/}" = "bash" -a "$_" = "$0" ]; then
     main "$@"
 fi