I am trying to use top to prove that my test process on a Leopardboard (embedded-linux) target has a memory leak. Why does this command
/ # top -b | grep test >> /media/top.txt &
seem to die immediately like this?
[3]+ Stopped (tty output) top -b | grep test 1>>/media/top.txt
I see that is has produced an empty file
-rwxr-xr-x 1 root root 0 Jan 15 15:35 top.txt
Top does run in interactive mode producing output like this
1079 1 root S 83668 289% 17% test
but I need to record what happens to the memory for this process over a long period of time to file.
Sounds like you have a buggy {top|shell|grep} in that order of likelyhood ;) Lemme guess it's a busybox-based system?
Perhaps a better alternative is to write a simple script to monitor the process' direct stats through the /proc file system. Some entries of interest to you might be
/proc//maps - info about currently mapped memory regions
/proc//smaps - memory consumption for each of the process's mappings
/proc//stat - some useful stats including resident set size (total current memory usage)
The man page proc(5) has much more information about what information is contained within these /proc/ entries.
Happy hunting!