Parsing Text String - command-line

Question

I have created a running windows process list to a text file using the command:
tasklist > c:\mytasklist.txt. The result something like this:
Image Name PID Session Name Session# Mem Usage
========================= ======== ================ =========== ============
System Idle Process 0 Services 0 24 K
System 4 Services 0 12.408 K
smss.exe 320 Services 0 1.236 K
csrss.exe 424 Services 0 4.720 K
wininit.exe 516 Services 0 4.684 K
csrss.exe 524 Console 1 7.888 K
winlogon.exe 572 Console 1 7.764 K
services.exe 620 Services 0 9.532 K
and so on...
My question:
How I parsing the line on the text file, so I get output like the following format using Lua script:
PID - Process Name - Memory Usage
And the output automatic sorted by the biggest memory usage

Answer 1

local tasklist = io.popen"tasklist /fo csv /nh"
local list = {}
for line in tasklist:lines() do
local exe, pid, mem = line:match'^"(.-)","(%d+)",.-"([^"]+)"$'
table.insert(list, {pid = tonumber(pid), exe = exe, mem = tonumber((mem:gsub("%D", "")))})
end
tasklist:close()
table.sort(list, function(a, b) return a.mem > b.mem end)
for j = 1, math.min(10, #list) do
print(list[j].pid, list[j].mem, list[j].exe)
end
Output:
1036 549416 svchost.exe
4972 439524 firefox.exe
6540 214476 plugin-container.exe
7144 169268 OUTLOOK.EXE
532 75320 svchost.exe
1948 71644 avp.exe
3752 62704 svchost.exe
5268 61100 explorer.exe
596 56732 csrss.exe
5048 50248 CcmExec.exe