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elixir - 分割文件名和提取时间长生不老药

问题描述

在这种模式下，我有近 100k 个文件。

["192.168.1.225_01_20190316070000734_TIMING.jpg",
 "192.168.1.225_01_20190316071000736_TIMING.jpg",
 "192.168.1.225_01_20190316072000736_TIMING.jpg",
 "Camera_1_615696208_20190318075200317_TIMING.jpg",
 "Camera_1_615696208_20190318080200322_TIMING.jpg",
 "Camera_1_615696208_20190318082200326_TIMING.jpg",
 "camera2_615696156_20190318080000375_TIMING.jpg",
 "camera2_615696156_20190318081000377_TIMING.jpg",
 "camera2_615696156_20190318093000394_TIMING.jpg"]

他们主要在我正在做的本地驱动器中File.ls(@picture_directory)

所有这些都是 3 台相机的图片，其标识符为

 cameras = %{
  "Camera_1_615696208_" => "nch1-zcpes",
  "camera2_615696156_" => "nch2-zkhcy",
  "192.168.1.225_01_" => "nch3-ipljs"
}

左侧是日期和时间之前的前缀。右侧是标识符。

我想做的是做3-tuple. 像这样..

[filename, datetime, indentifier]

假设在一个文件中。

["192.168.1.225_01_20190316070000734_TIMING.jpg", "20190316070000734", "nch3-ipljs']

到目前为止，我已经尝试过了。

defmodule EvercamMedia.Nch do
  @picture_directory "/home/junaid/Desktop/NCH"

  def move do
    cameras = %{
      "Camera_1_615696208_" => "nch1-zcpes",
      "camera2_615696156_" => "nch2-zkhcy",
      "192.168.1.225_01_" => "nch3-ipljs"
    }

    File.ls!(@picture_directory)
    |> Enum.sort
    |> Enum.map(fn file ->
      Enum.each(cameras, fn cam ->
        {prefix, exid} = cam
        with true <- String.contains?(file, prefix) do
          datetime = file |> String.trim_leading(prefix) |> String.trim_trailing("_TIMING.jpg")
          [file, datetime, exid]
        else
          _ -> :noop
        end
      end)
    end)
  end
end

但这只会返回一个列表：ok..

标签： elixir

解决方案

这会解析每个文件名中的日期，并将其放在一个列表中，就像您的示例一样。

[
  "192.168.1.225_01_20190316070000734_TIMING.jpg",
  "192.168.1.225_01_20190316071000736_TIMING.jpg",
  "192.168.1.225_01_20190316072000736_TIMING.jpg",
  "Camera_1_615696208_20190318075200317_TIMING.jpg",
  "Camera_1_615696208_20190318080200322_TIMING.jpg",
  "Camera_1_615696208_20190318082200326_TIMING.jpg",
  "camera2_615696156_20190318080000375_TIMING.jpg",
  "camera2_615696156_20190318081000377_TIMING.jpg",
  "camera2_615696156_20190318093000394_TIMING.jpg"
]
|> Enum.map(fn
  "192.168.1.225_01_" <> <<date::binary-size(17)>> <> _ = file -> [file, date, "nch3-ipljs"]
  "Camera_1_615696208_" <> <<date::binary-size(17)>> <> _ = file -> [file, date, "nch1-zcpes"]
  "camera2_615696156_" <> <<date::binary-size(17)>> <> _ = file -> [file, date, "nch2-zkhcy"]
end)

输出：

[
  ["192.168.1.225_01_20190316070000734_TIMING.jpg", "20190316070000734",
   "nch3-ipljs"],
  ["192.168.1.225_01_20190316071000736_TIMING.jpg", "20190316071000736",
   "nch3-ipljs"],
  ["192.168.1.225_01_20190316072000736_TIMING.jpg", "20190316072000736",
   "nch3-ipljs"],
  ["Camera_1_615696208_20190318075200317_TIMING.jpg", "20190318075200317",
   "nch1-zcpes"],
  ["Camera_1_615696208_20190318080200322_TIMING.jpg", "20190318080200322",
   "nch1-zcpes"],
  ["Camera_1_615696208_20190318082200326_TIMING.jpg", "20190318082200326",
   "nch1-zcpes"],
  ["camera2_615696156_20190318080000375_TIMING.jpg", "20190318080000375",
   "nch2-zkhcy"],
  ["camera2_615696156_20190318081000377_TIMING.jpg", "20190318081000377",
   "nch2-zkhcy"],
  ["camera2_615696156_20190318093000394_TIMING.jpg", "20190318093000394",
   "nch2-zkhcy"]
]

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