GNU ParallelでAndroid NDKの全バージョンを一括ダウンロード

----

Android NDKのセットアップするついでに「どーせなら過去バージョンもダウンロードしちゃえ」と思ったので`parallel`の練習ついでにやってみた。
shellはzshです。

`-jN`で同時実行数抑えるの大事！

```
[mazgi@Mac] $ parallel -j4 --eta curl -sLI {} \| head -1 \| grep -qi \'200 ok\' \&\& curl -LOR {} ::: http://dl.google.com/android/ndk/android-ndk-r{1..9}{"",{b-e}}-darwin-x86.tar.bz2

Computers / CPU cores / Max jobs to run
1:local / 8 / 4

Computer:jobs running/jobs completed/%of started jobs/Average seconds to complete
ETA  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 47.8M  100 47.8M    0     0  3057k      0  0:00:16  0:00:16 --:--:-- 2395k
ETA: 1  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 47.8M  100 47.8M    0     0  2845k      0  0:00:17  0:00:17 --:--:-- 4052k
ETA: 1  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 50.2M  100 50.2M    0     0  2739k      0  0:00:18  0:00:18 --:--:-- 3530k
ETA: 9s 10left 1.00avg  local:4/22  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 50.3M  100 50.3M    0     0  4598k      0  0:00:11  0:00:11 --:--:-- 4108k
ETA  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 48.3M  100 48.3M    0     0  1570k      0  0:00:31  0:00:31 --:--:-- 3067k
ETA: 10s 7left 1.44avg    % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 67.9M  100 67.9M    0     0  2630k      0  0:00:26  0:00:26 --:--:-- 2649k
E  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 70.3M  100 70.3M    0     0  2705k      0  0:00:26  0:00:26 --:--:-- 1749k
ETA: 9s 5left 1.81avg    % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 70.4M  100 70.4M    0     0  2865k      0  0:00:25  0:00:25 --:--:-- 2962k
ETA: 8s 4left 2.07avg  loc  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 92.1M  100 92.1M    0     0  2459k      0  0:00:38  0:00:38 --:--:-- 1876k
ETA: 7s 3left 2.52avg  loc  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100  172M  100  172M    0     0  2704k      0  0:01:05  0:01:05 --:--:-- 3254k
ETA: 11s 2left 3.73avg  local:2/30/  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100  204M  100  204M    0     0  3186k      0  0:01:05  0:01:05 --:--:-- 2730k
ETA: 7s 1left 3.65avg  local:1/31/100%/  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100  294M  100  294M    0     0  5133k      0  0:00:58  0:00:58 --:--:-- 8025k
ETA: 3s 0left 3.56avg  local:0/32/100%/3.6s 
[mazgi@Mac] $ ll
total 2492320
-rw-r--r--  1 mazgi  staff   50210863 Dec  7  2010 android-ndk-r5-darwin-x86.tar.bz2
-rw-r--r--  1 mazgi  staff   50217983 Jan 27  2011 android-ndk-r5b-darwin-x86.tar.bz2
-rw-r--r--  1 mazgi  staff   50714712 Jun  8  2011 android-ndk-r5c-darwin-x86.tar.bz2
-rw-r--r--  1 mazgi  staff   52682746 Jul 12  2011 android-ndk-r6-darwin-x86.tar.bz2
-rw-r--r--  1 mazgi  staff   52798843 Aug 31  2011 android-ndk-r6b-darwin-x86.tar.bz2
-rw-r--r--  1 mazgi  staff   71262092 Nov 12  2011 android-ndk-r7-darwin-x86.tar.bz2
-rw-r--r--  1 mazgi  staff   73817184 Feb 15  2012 android-ndk-r7b-darwin-x86.tar.bz2
-rw-r--r--  1 mazgi  staff   73836512 Apr 10  2012 android-ndk-r7c-darwin-x86.tar.bz2
-rw-r--r--  1 mazgi  staff   96650992 May  2  2012 android-ndk-r8-darwin-x86.tar.bz2
-rw-r--r--  1 mazgi  staff  181255568 Jul 19  2012 android-ndk-r8b-darwin-x86.tar.bz2
-rw-r--r--  1 mazgi  staff  214270840 Nov 14 03:00 android-ndk-r8c-darwin-x86.tar.bz2
-rw-r--r--  1 mazgi  staff  308328942 Dec 21 07:00 android-ndk-r8d-darwin-x86.tar.bz2
```