lua rewrite

modules/util.lua

@@ -0,0 +1,95 @@
+local M = {}
+
+-- Helper functions
+
+function M.format_time(time)
+    local seconds = time
+    local days = math.floor(seconds / 86400)
+    local hours = math.floor(seconds % 86400 / 3600)
+    local minutes = math.floor(seconds % 3600 / 60)
+    local result = ""
+
+    if days > 0 then
+        result = result .. days .. "d "
+    end
+
+    if hours > 0 then
+        result = result .. hours .. "h "
+    end
+
+    if minutes > 0 then
+        result = result .. minutes .. "m"
+    end
+
+    return result
+end
+
+-- Capture the first line of an invoked system process
+-- (discards of error messages of the last command (the
+-- one after the last pipe ('|')))
+function M.process_get_one_line(proc)
+    local pipe = io.popen(proc .. " 2>/dev/null", "r")
+    if not pipe then return nil end
+
+    local data = pipe:read("*l")
+    pipe:close()
+    return data
+end
+
+-- Get the lenght of the longest info name (for padding)
+function M.longest_info_name_length(modules)
+    local longest = 0
+
+    for _, mod in ipairs(modules) do
+        if type(mod.name) == "string" and #mod.name > longest then
+            longest = #mod.name
+        end
+    end
+
+    return longest
+end
+
+--[[
+-- Loop through a file and for each line perform
+-- a callback function, if it returns true, the
+-- loop can end prematurely (this is wanted)
+--]]
+function M.for_line_in_file(filename, callback)
+    local file = io.open(filename, "r")
+    if not file then return nil end
+
+    for line in file:lines() do
+        if callback(line) then
+            file:close()
+            return true
+        end
+    end
+
+    file:close()
+    return false
+end
+
+-- filter a file line-by-line and return the given match
+function M.grep(filename, regex)
+    local capture
+
+    M.for_line_in_file(filename, function(line)
+        capture = line:match(regex)
+
+        return capture ~= nil
+    end)
+
+    return capture
+end
+
+-- Returns the contents of the first line in a file
+function M.cat_first_line(filename)
+    local file = io.open(filename, "r")
+    if not file then return nil end
+
+    local line = file:read("*l")
+    file:close()
+    return line
+end
+
+return M