knoppix@Microknoppix:~/perl/Monks$ perl -ni.BAK -e '
print unless m{^my \$t0 = \[gettimeofday\];} .. m{^\s+\}};' d971401/*.pm
knoppix@Microknoppix:~/perl/Monks$ ls d971401/*
d971401/File1.pm      d971401/File3.pm      d971401/File5.pm
d971401/File1.pm.BAK  d971401/File3.pm.BAK  d971401/File5.pm.BAK
d971401/File2.pm      d971401/File4.pm
d971401/File2.pm.BAK  d971401/File4.pm.BAK
knoppix@Microknoppix:~/perl/Monks$