Linux - Displaying Memory Usage Live

Question

I'm running GNU - Screen (4.03.01) so I can have multiple terminals in one, and I'm looking for a good way to display live stats of my memory, so as I do things like compiling, testing programs, etc... I can see how much resources I have left.

I know there is "TOP" the performance monitor... and other similar programs, but I'm not looking for the entire active process list etc... I just want a snapshot of my memory stats that updates for example every 3-5 seconds.

I really appreciate anyone taking the time to help me with this, so thank you!

(for visualization purposes)

Screenshot:

Answer 1

You can use the combination of watch which repeats the specified program and displays its output and free which shows current memory usage

watch free -m

free --help

Usage:
 free [options]

Options:
 -b, --bytes         show output in bytes
 -k, --kilo          show output in kilobytes
 -m, --mega          show output in megabytes
 -g, --giga          show output in gigabytes
     --tera          show output in terabytes
 -h, --human         show human-readable output
     --si            use powers of 1000 not 1024
 -l, --lohi          show detailed low and high memory statistics
 -o, --old           use old format (without -/+buffers/cache line)
 -t, --total         show total for RAM + swap
 -s N, --seconds N   repeat printing every N seconds
 -c N, --count N     repeat printing N times, then exit

     --help     display this help and exit
 -V, --version  output version information and exit

For more details see free(1).

watch --help

Usage:
 watch [options] command

Options:
  -b, --beep             beep if command has a non-zero exit
  -c, --color            interpret ANSI color sequences
  -d, --differences[=]
                         highlight changes between updates
  -e, --errexit          exit if command has a non-zero exit
  -g, --chgexit          exit when output from command changes
  -n, --interval   seconds to wait between updates
  -p, --precise          attempt run command in precise intervals
  -t, --no-title         turn off header
  -x, --exec             pass command to exec instead of "sh -c"

 -h, --help     display this help and exit
 -v, --version  output version information and exit