foreach ( @i ) {
  my @proc = /^
            (\w+)            # capture username
            \s+
            (\d+)            # capture PID
            \s+\d+\s+\d+\s+
            (              # cluster (not capturing)
              \d{4}              # capture %Y
              |                    # or
              \d{2}:\d{2}        # capture %H:%M
              |                    # or
              \d{2}:\d{2}:\d{2}  # capture %H:%M:%S
              |                    # or
              \w{3}\d{2}         # capture %b%d
              |                    # or
              \w{3}\s+\d{2}      # capture %b %d
            )
            \s+\S+\s+\S+\s+  # skip 2 columns after the 5th column
            (.*)             # capture the command
    $/gx;

    print join ' | ', @proc;
    print "\n";
}