Prefix time to each line of bash command output

Look at the ts command from the moreutils package:

NAME ts - timestamp input SYNOPSIS ts [-r] [format] DESCRIPTION ts adds a timestamp to the beginning of each line of input. 

You can e.g. use it as such:

$ top -n 1 | grep init | ts aug 28 17:15:00 1 root 20 0 24448 2272 1340 S 0 0.1 0:01.07 init 

The ps command is better suited for this kind of task. Try something like this:

$ ps -ao bsdstart,fuser,pid,%cpu,%mem,args | grep jre 

From the ps man page:

ps displays information about a selection of the active processes. If you want a repetitive update of the selection and the displayed information, use top(1) instead.

In the command I suggested, the option '-a' tells ps to print processes for all users. The -o specifies the output format. In my example (again from the ps man page):

bsdstart : time the command started. If the process was started less than 24 hours ago, the output format is " HH:MM", else it is " Mmm:SS" (where Mmm is the three letters of the month). See also lstart, start, start_time, and stime. fuser : filesystem access user ID. This will be the textual user ID, if it can be obtained and the field width permits, or a decimal representation otherwise. pid : a number representing the process ID (alias tgid). %cpu : cpu utilization of the process in "##.#" format. Currently, it is the CPU time used divided by the time the process has been running (cputime/realtime ratio), expressed as a percentage. It will not add up to 100% unless you are lucky. (alias pcpu). %mem : ratio of the process's resident set size to the physical memory on the machine, expressed as a percentage. (alias pmem). args : command with all its arguments as a string. Modifications to the arguments may be shown. The output in this column may contain spaces. A process marked <defunct> is partly dead, waiting to be fully destroyed by its parent. Sometimes the process args will be unavailable; when this happens, ps will instead print the executable name in brackets. (alias cmd, command). See also the comm format keyword, the -f option, and the c option. When specified last, this column will extend to the edge of the display. If ps can not determine display width, as when output is redirected (piped) into a file or another command, the output width is undefined (it may be 80, unlimited, determined by the TERM variable, and so on). The COLUMNS environment variable or --cols option may be used to exactly determine the width in this case. The w or -w option may be also be used to adjust width. 

You can change this to suit your needs. Have a look at man ps and search for "STANDARD FORMAT SPECIFIERS" (you can use vi-style search in man pages, hit "/" and enter your search pattern, "n" will move to the next match).