title: Memory usage using /usr/bin/time for a giving program
body: <p>I Would like to know how can I gather the memory usage of one program/command (eg. gcc ...) using time command.
  Many properties are reported in the documentation of 'time' command. I don't know which one I should  use:</p>
  
  <p>Memory</p>
  
  <pre><code>   %M     Maximum resident set size of the process during its lifetime,
            in Kbytes.
  
     %t     (Not in tcsh(1).)  Average resident set size of the process,
            in Kbytes.
  
     %K     Average total (data+stack+text) memory use of the process, in
            Kbytes.
  
     %D     Average size of the process's unshared data area, in Kbytes.
  
     %p     (Not in tcsh(1).)  Average size of the process's unshared
            stack space, in Kbytes.
  
     %X     Average size of the process's shared text space, in Kbytes.
  
     %Z     (Not in tcsh(1).)  System's page size, in bytes.  This is a
            per-system constant, but varies between systems.
  
     %F     Number of major page faults that occurred while the process
            was running.  These are faults where the page has to be read
            in from disk.
  
     %R     Number of minor, or recoverable, page faults.  These are
            faults for pages that are not valid but which have not yet
            been claimed by other virtual pages.  Thus the data in the
            page is still valid but the system tables must be updated.
  
     %W     Number of times the process was swapped out of main memory.
  
     %c     Number of times the process was context-switched involuntarily
            (because the time slice expired).
  
     %w     Number of waits: times that the program was context-switched
            voluntarily, for instance while waiting for an I/O operation
            to complete.
  </code></pre>