The backup suffix for -i may not be separated by a space. diff -Naur perl-5.8.1.orig/pod/perlrun.pod perl-5.8.1/pod/perlrun.pod --- perl-5.8.1.orig/pod/perlrun.pod 2003-09-10 01:42:21.000000000 +1000 +++ perl-5.8.1/pod/perlrun.pod 2003-09-28 11:22:17.000000000 +1000 @@ -444,20 +444,20 @@ This allows you to add a prefix to the backup file, instead of (or in addition to) a suffix: - $ perl -pi 'orig_*' -e 's/bar/baz/' fileA # backup to 'orig_fileA' + $ perl -pi'orig_*' -e 's/bar/baz/' fileA # backup to 'orig_fileA' Or even to place backup copies of the original files into another directory (provided the directory already exists): - $ perl -pi 'old/*.orig' -e 's/bar/baz/' fileA # backup to 'old/fileA.orig' + $ perl -pi'old/*.orig' -e 's/bar/baz/' fileA # backup to 'old/fileA.orig' These sets of one-liners are equivalent: $ perl -pi -e 's/bar/baz/' fileA # overwrite current file - $ perl -pi '*' -e 's/bar/baz/' fileA # overwrite current file + $ perl -pi'*' -e 's/bar/baz/' fileA # overwrite current file - $ perl -pi '.orig' -e 's/bar/baz/' fileA # backup to 'fileA.orig' - $ perl -pi '*.orig' -e 's/bar/baz/' fileA # backup to 'fileA.orig' + $ perl -pi'.orig' -e 's/bar/baz/' fileA # backup to 'fileA.orig' + $ perl -pi'*.orig' -e 's/bar/baz/' fileA # backup to 'fileA.orig' From the shell, sayingThread Next