Lua exact match line from file

Question

So here is my scenario :

I have nginx-lua config, that it contains json data (from POST request) :

{
    "profile_name": "test",
    "number_from_json": "12",
}

In my /opt/file1.csv

1283813122344
12
12838138931316
128381383131

I have

So I'm having this config

location /reader_x {
   proxy_set_header X-Forwarded-Host $host;
   proxy_set_header X-Forwarded-Server $host;
   proxy_set_header X-Real-IP $remote_addr;
   proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
   proxy_set_header X-Url-Scheme $scheme;
   proxy_set_header X-Forwarded-Proto $scheme;
   proxy_set_header Host $http_host;
   proxy_redirect off;
   proxy_pass_request_body on;
   proxy_pass_request_headers on;
   proxy_ssl_verify off;
   if ($request_method = POST ) {
   rewrite_by_lua '
   ngx.req.read_body()
   local check_body = ngx.req.get_body_data()
   local data = ngx.req.get_body_data()
   json = require "dkjson"
   local json_parse = json.decode(check_body)
   local number_cut = json_parse.number_from_json
   local filepath = "/opt/file1.csv"
   local open_file = io.open(filepath, "rb")
   local second_one = open_file:read("*a")
   io.close(open_file)
   local  match0 = string.match(number_cut, second_one)
   if match0 then
   ngx.say("this is exactly matched 12")
else
   ngx.say("not matching")
   end
   ';
proxy_pass https://localhost:8421 ;

So I need only to match 12 unique number, not if the other numbers are contains "12"

Let me know if you need more info

rodvlopes · Accepted Answer · 2023-03-06T18:04:38.037

2

You may be using the string.match parameters switched.

If I got the point, your question could be "how to match the whole word in Lua". This is a working example based on your scenario:

local number_cut = 12
local second_one = [[
1283813122344
12
12838138931316
128381383131
]]

local match0 = string.match(second_one, "%f[%w_]" .. number_cut .. "%f[^%w_]")

if (match0) then
    print "this is exactly matched 12"
else
    print "not matching"
end

https://ideone.com/P18FxV

Ref.: how to check if a word appears as a whole word in a string in Lua

edited Mar 06 '23 at 18:04

answered Mar 06 '23 at 15:30

rodvlopes

895
1
8
18

Thanks so much @rodvlopes. Works like charm. Can you please let me know what is the %f[%w_] pattern? Thanks! – Vancho Mar 06 '23 at 16:52
Please have a look on the reference link that is on the bottom of the answer, it explains how word boundary works in Lua. – rodvlopes Mar 06 '23 at 18:06

Lua exact match line from file

1 Answers1