How do I write a bash script that will let users choose the value of the MIRROR environment variable?

Question

I am presently in the process of writing a Bash function that when invoked will ask users to choose from a list of Sabayon's mirrors, but I would like it if each option could include info on the mirror in question, like its country and connection speed. Currently I have this Bash function:

function sabayon-mirror {
  L=('ftp://mirrors.coopvgg.com.ar/sabayon/ 
  ftp://gd.tuwien.ac.at/linux/sabayonlinux/
  ftp://mirror.optusnet.com.au/sabayon')
  select x in "${L[@]}"
  do
    export MIRROR="$x"
  done
}

Adding the mirror info after each URL makes the info be treated like another option to be selected from.

EDIT: Chaos' answer was what I was originally looking for, but if you have an answer that doesn't require me to list every mirror manually (but rather can fetch it from a remote list) I would still love to hear about it.

how do you propose to get the information you want to write out? or are you asking how? if the latter, it might be a good idea to ask in a sabayon forum. — mikeserv, Nov 25 '15 at 12:00
The info about each mirror I'm willing to provide to the script (like manually writing it in for each mirror I list), I'm just asking how might I show the info on each mirror in the select interface. — Josh Pinto, Nov 25 '15 at 12:06
oh gee. are you sure? dunno about sabayon, but it seems to me that ought to be available to you. on an arch system it is in `/etc/pacman.d/mirrors.`*`forgot extension`*. but i use the [`json`](https://www.archlinux.org/mirrors/status/json/) or [url query](https://www.archlinux.org/mirrorlist/?country=US&protocol=https&use_mirror_status=on) interfaces. all of the distros do stuff like that - mirror status is a big deal to the distro maintainers. there's gotta be something like that you can do - live. — mikeserv, Nov 25 '15 at 12:13
Thanks, ya gave me an idea something like that is available for Sabayon, but nonetheless I'd like this answer in Bash script as I am working on other Bash scripts that will use the `$MIRROR` environment variable. — Josh Pinto, Nov 25 '15 at 12:15
well, you're already connecting in the bash script as it is. im not suggesting you switch languages, just that you make another query. oh, you're not. but you *should*. — mikeserv, Nov 25 '15 at 12:17

score 3 · Accepted Answer · answered Nov 25 '15 at 12:17

How about that:

function sabayon-mirror {
  L=('Info about mirror 1 - ftp://mirrors.coopvgg.com.ar/sabayon/' 
  'Info about mirror 2 - ftp://gd.tuwien.ac.at/linux/sabayonlinux/'
  'Info about mirror 3 - ftp://mirror.optusnet.com.au/sabayon')
  select x in "${L[@]}"
  do
    export MIRROR="${x#*-}"
  done
}

The Info is part of the item. But, when exporting the variable value, it is removed.

score 2 · Answer 2 · answered Nov 25 '15 at 14:27

You are defining an array with a single entry in your script. SInce you are single quoting all elements, they will be treated as a single, long string. Array elements in bash are separated by spaces so you need to quote each separately:

L=('ftp://mirrors.coopvgg.com.ar/sabayon/' 
  'ftp://gd.tuwien.ac.at/linux/sabayonlinux/'
  'ftp://mirror.optusnet.com.au/sabayon')

That said, since you are using bash, you can use associative arrays:

function sabayon-mirror {
  declare -A L=(
    [Info about mirror 1]="ftp://mirrors.coopvgg.com.ar/sabayon/"
    [Info about mirror 2]="ftp://gd.tuwien.ac.at/linux/sabayonlinux/"
    [Info about mirror 3]="ftp://mirror.optusnet.com.au/sabayon")
  select x in "${!L[@]}"
  do
    export MIRROR="${L[$x]}"
  done
}

With that in mind, I took the list of Sabayon mirrors from here and wrote the function for you:

## Declare the associative array
declare -A L=(
[Argentina 1]="ftp://mirrors.coopvgg.com.ar/sabayon/entropy"              [Argentina 2]="http://mirrors.coopvgg.com.ar/sabayon/entropy"
[Austria 1]="ftp://gd.tuwien.ac.at/linux/sabayonlinux/entropy"            [Austria 2]="http://gd.tuwien.ac.at/linux/sabayonlinux/entropy"
[Australia 1]="ftp://mirror.internode.on.net/pub/sabayon/entropy"         [Australia 2]="http://mirror.internode.on.net/pub/sabayon/entropy"
[Australia 3]="ftp://mirror.optusnet.com.au/sabayon/entropy"              [Australia 4]="http://mirror.optusnet.com.au/sabayon/entropy"
[Belgium 1]="ftp://ftp.belnet.be/mirror/sabayonlinux/entropy"             [Belgium 2]="http://ftp.belnet.be/mirror/sabayonlinux/entropy"
[Brazil 1]="ftp://sabayon.c3sl.ufpr.br/sabayon/entropy"                   [Brazil 2]="http://sabayon.c3sl.ufpr.br/entropy"
[Czech Republic 1]="ftp://mirror.dkm.cz/pub/sabayon/entropy"              [Czech Republic 2]="http://sabayon.mirror.dkm.cz/pub/sabayon/entropy"
[Germany 1]="http://mirror.de.sabayon.org/entropy"                        [Denmark 1]="ftp://ftp.klid.dk/sabayonlinux/enttropy"
[Denmark 2]="http://ftp.klid.dk/sabayonlinux/entropy"                     [Greece 1]="ftp://ftp.cc.uoc.gr/mirrors/linux/SabayonLinux/entropy"
[Greece 2]="http://ftp.cc.uoc.gr/mirrors/linux/SabayonLinux/entropy"      [Hungary 1]="ftp://ftp.fsn.hu/pub/linux/distributions/sabayon/entropy"
[Hungary 2]="http://ftp.fsn.hu/pub/linux/distributions/sabayon/entropy"   [Italy 1]="http://mirror.it.sabayon.org/entropy"
[Italy 2]="ftp://na.mirror.garr.it/mirrors/sabayonlinux/entropy"          [Italy 3]="http://na.mirror.garr.it/mirrors/sabayonlinux/entropy"
[Japan 1]="ftp://ftp.riken.jp/Linux/sabayon/entropy"                      [Japan 2]="http://ftp.riken.jp/Linux/sabayon/entropy"
[Japan 3]="ftp://ftp.kddilabs.jp/Linux/packages/sabayonlinux/entropy"     [Japan 4]="http://ftp.kddilabs.jp/Linux/packages/sabayonlinux/entropy"
[Japan 5]="http://ftp.tsukuba.wide.ad.jp/Linux/sabayon/entropy"           [Netherlands 1]="ftp://ftp.nluug.nl/pub/os/Linux/distr/sabayonlinux/entropy"
[Netherlands 2]="http://ftp.nluug.nl/os/Linux/distr/sabayonlinux/entropy" [Netherlands 3]="ftp://ftp.surfnet.nl/pub/os/Linux/distr/sabayonlinux/entropy"
[Portugal 1]="ftp://glua.ua.pt/sabayon/entropy"                           [Portugal 2]="ftp://ftp.rnl.ist.utl.pt/pub/sabayon/entropy"
[Portugal 3]="http://ftp.rnl.ist.utl.pt/pub/sabayon/entropy"              [Russian Federation 1]="ftp://mirror.yandex.ru/sabayon/entropy"
[Russian Federation 2]="http://mirror.yandex.ru/sabayon/entropy"          [Sweden 1]="ftp://ftp.portlane.com/pub/os/linux/sabayon/entropy"
[Sweden 2]="http://ftp.portlane.com/pub/os/linux/sabayon/entropy"         [United States 1]="ftp://mirrors-usa.go-parts.com/sabayon/entropy"
[United States 2]="http://mirrors-usa.go-parts.com/sabayon/entropy"       [United States 3]="ftp://mirror.cs.vt.edu/pub/SabayonLinux/entropy"
[United States 4]="http://mirror.cs.vt.edu/pub/SabayonLinux/entropy"      [United States 5]="http://cross-lfs.sabayonlinux.org/entropy"
[United States 6]="http://mirror.clarkson.edu/sabayon/entropy"            [United States 7]="http://mirror.umd.edu/sabayonlinux/entropy"
[South Africa 1]="ftp://sabayon.mirror.ac.za/entropy"                     [South Africa 2]="http://sabayon.mirror.ac.za/entropy"
)
## Unfortunately, associative arrays are not stored in the
## order you create them with so, to have the select show
## sorted options, we need a second, helper array.
sorted=(
[1]="Argentina 1"             [2]="Argentina 2"             [3]="Australia 1"
[4]="Australia 2"             [5]="Australia 3"             [6]="Australia 4"
[7]="Austria 1"               [8]="Austria 2"               [9]="Belgium 1"
[10]="Belgium 2"              [11]="Brazil 1"               [12]="Brazil 2"
[13]="Czech Republic 1"       [14]="Czech Republic 2"       [15]="Denmark 1"
[16]="Denmark 2"              [17]="Germany 1"              [18]="Greece 1"
[19]="Greece 2"               [20]="Hungary 1"              [21]="Hungary 2"
[22]="Italy 1"                [23]="Italy 2"                [24]="Italy 3"
[25]="Japan 1"                [26]="Japan 2"                [27]="Japan 3"
[28]="Japan 4"                [29]="Japan 5"                [30]="Netherlands 1"
[31]="Netherlands 2"          [32]="Netherlands 3"          [33]="Portugal 1"
[34]="Portugal 2"             [35]="Portugal 3"             [36]="Russian Federation 1"
[37]="Russian Federation 2"   [38]="South Africa 1"         [39]="South Africa 2"
[40]="Sweden 1"               [41]="Sweden 2"               [42]="United States 1"
[43]="United States 2"        [44]="United States 3"        [45]="United States 4"
[46]="United States 5"        [47]="United States 6"        [48]="United States 7"
)
select x in "${sorted[@]}"
do
    export MIRROR="${L[$x]}"
    break
done

There's bound to be a better way to do this, I'm sure the available mirrors are stored somewhere in your Sabayon system, but I don't use Sabayon so I don't know. According to the page I linked to above, they are probably stored in /etc/entropy/repositories.conf.d. If you edit your question with the format of that directory, we should be able to help you generate the mirror list on the fly.

How do I write a bash script that will let users choose the value of the MIRROR environment variable?

2 Answers2