I found this weather program on the main page (it seems to rotate what it here):

// Get your local weather report
pragma(lib, "curl");
import std.functional, std.json, std.net.curl,
    std.stdio, std.string;

alias getJSON = pipe!(get, parseJSON);
auto K2C = (float f) => f - 273.15;
auto K2F = (float f) => f / 5 * 9 - 459.67;

void main()
{
    auto loc = getJSON("ipinfo.io/")["loc"]
        .str.split(",");
    auto resp = getJSON(
        "api.openweathermap.org/data/2.5/weather" ~
        "?lat=" ~ loc[0] ~ "&lon=" ~ loc[1]);

    auto city = resp["name"].str;
    auto country = resp["sys"]["country"].str;
    auto desc = resp["weather"][0]["description"].str;
    auto temp = resp["main"]["temp"].floating;

    writefln(`
        +-----------------------------------------+
        |%s|
        +-----------------------------------------+
        |  weather      |  %-23s|
        +-----------------------------------------+
        |  temperature  |  %.2f°C (%.2f°F)      |
        +-----------------------------------------+
        `.outdent,
        centerJustifier(city ~ ", " ~ country, 41),
        desc, temp.K2C, temp.K2F);
}

I am compiling on Ubuntu 14.02 with DMD v2.066.1

I get this compile error:

weather_report.d(32): Error: undefined identifier centerJustifier

On Sunday 23 August 2015 11:54, Tony wrote:

> weather_report.d(32): Error: undefined identifier centerJustifier

`centerJustifier` is new in 2.068. You're probably using an older version of D. You can replace `centerJustifier` with `center` here.

On Sunday, 23 August 2015 at 09:54:37 UTC, Tony wrote:
> I found this weather program on the main page (it seems to rotate what it here):
>
> [...]

try with `center()` or update the compiler. centerJustifier() was added on 25 Apr 2015 so after 2.066.1 release:

https://github.com/D-Programming-Language/phobos/commit/f85101eea1b875311e5716143cd6346fe4655f02

Thanks for the replies. It compiles OK with just. However, it isn't linking:

/usr/bin/ld: cannot find -lcurl


I do have some versions of libcurl on my system:

/usr/lib/x86_64-linux-gnu/libcurl.so.3
/usr/lib/x86_64-linux-gnu/libcurl.so.4.3.0
/usr/lib/x86_64-linux-gnu/libcurl.so.4

I see there is a -L option to pass things to the linker

-Llinkerflag   pass linkerflag to link

but I am not sure how to use it.

On Sunday, 23 August 2015 at 16:00:19 UTC, Tony wrote:
> Thanks for the replies. It compiles OK with just. However, it isn't linking:
>
> /usr/bin/ld: cannot find -lcurl
>
>
> I do have some versions of libcurl on my system:
>
> /usr/lib/x86_64-linux-gnu/libcurl.so.3
> /usr/lib/x86_64-linux-gnu/libcurl.so.4.3.0
> /usr/lib/x86_64-linux-gnu/libcurl.so.4
>
> I see there is a -L option to pass things to the linker
>
> -Llinkerflag   pass linkerflag to link
>
> but I am not sure how to use it.

I tried

ld weather_report.o -lcurl -L/usr/lib/x86_64-linux-gnu

and

ld weather_report.o -lcurl -L /usr/lib/x86_64-linux-gnu

but it also says it can't find libcurl:

ld: cannot find -lcurl

On Sunday, 23 August 2015 at 16:00:19 UTC, Tony wrote:
> /usr/bin/ld: cannot find -lcurl

Just the other day I had a similar problem (compiling vibenews, ld complained of missing -levent and -lssl), which I managed to solve simply by installing the development versions of the libraries (i.e. libevent-dev and libssl-dev). Maybe if you install libcurl-dev you will have the same luck I had. (But hopefully someone will give a more enlightened reply.)

On Sun, 23 Aug 2015 16:00:16 +0000, Tony wrote:

> Thanks for the replies. It compiles OK with just. However, it isn't linking:
> 
> /usr/bin/ld: cannot find -lcurl
> 
> 
> I do have some versions of libcurl on my system:
> 
> /usr/lib/x86_64-linux-gnu/libcurl.so.3 /usr/lib/x86_64-linux-gnu/libcurl.so.4.3.0 /usr/lib/x86_64-linux-gnu/libcurl.so.4
> 
> I see there is a -L option to pass things to the linker
> 
> -Llinkerflag   pass linkerflag to link
> 
> but I am not sure how to use it.

I've had the same problem recently. What I did was that I ran `dmd main.d
-L-L/usr/lib/x86_64-linux-gnu/ -L-lcurl -v`. It would still fail to link,
but I can find the linking command from the verbose output. It was
something like this: `gcc main.o -o main -m64 -L/usr/lib/x86_64-linux-
gnu/ -lcurl -L/usr/lib/x86_64-linux-gnu -Xlinker --export-dynamic -
l:libphobos2.a -lpthread -lm -lrt`.
As you can see, -lcurl is there, but it still needs to be added again
after -l:libphobos2.a. So just add it again so the command becomes:
`gcc main.o -o main -m64 -L/usr/lib/x86_64-linux-gnu/ -lcurl -L/usr/lib/
x86_64-linux-gnu -Xlinker --export-dynamic -l:libphobos2.a -lpthread -lm -
lrt -lcurl`. And it links and runs.

On Sunday, 23 August 2015 at 16:20:04 UTC, Gerald Jansen wrote:
> On Sunday, 23 August 2015 at 16:00:19 UTC, Tony wrote:
>> /usr/bin/ld: cannot find -lcurl
>
> Just the other day I had a similar problem (compiling vibenews, ld complained of missing -levent and -lssl), which I managed to solve simply by installing the development versions of the libraries (i.e. libevent-dev and libssl-dev). Maybe if you install libcurl-dev you will have the same luck I had. (But hopefully someone will give a more enlightened reply.)

Synaptic gave me a choice of 3 libcurl*
libcurl4-nss-dev (NSS flavour)
libcurl4-gnutls-dev (GnuTLS flavour)
libcurl4-openssl-dev (OpenSSL flavour)

Confusing that there are 3 choices.

I downloaded the OpenSSL one and the "can't find lcurl" has gone away. But I am now getting linking errors with regard to curl certain curl functions not being found.

On Monday, 24 August 2015 at 06:28:34 UTC, Yazan D wrote:
> On Sun, 23 Aug 2015 16:00:16 +0000, Tony wrote:
>
>> Thanks for the replies. It compiles OK with just. However, it isn't linking:
>> 
>> /usr/bin/ld: cannot find -lcurl
>> 
>> 
>> I do have some versions of libcurl on my system:
>> 
>> /usr/lib/x86_64-linux-gnu/libcurl.so.3 /usr/lib/x86_64-linux-gnu/libcurl.so.4.3.0 /usr/lib/x86_64-linux-gnu/libcurl.so.4
>> 
>> I see there is a -L option to pass things to the linker
>> 
>> -Llinkerflag   pass linkerflag to link
>> 
>> but I am not sure how to use it.
>
> I've had the same problem recently. What I did was that I ran `dmd main.d
> -L-L/usr/lib/x86_64-linux-gnu/ -L-lcurl -v`. It would still fail to link,
> but I can find the linking command from the verbose output. It was
> something like this: `gcc main.o -o main -m64 -L/usr/lib/x86_64-linux-
> gnu/ -lcurl -L/usr/lib/x86_64-linux-gnu -Xlinker --export-dynamic -
> l:libphobos2.a -lpthread -lm -lrt`.
> As you can see, -lcurl is there, but it still needs to be added again
> after -l:libphobos2.a. So just add it again so the command becomes:
> `gcc main.o -o main -m64 -L/usr/lib/x86_64-linux-gnu/ -lcurl -L/usr/lib/
> x86_64-linux-gnu -Xlinker --export-dynamic -l:libphobos2.a -lpthread -lm -
> lrt -lcurl`. And it links and runs.

I  had an additional -lcurl in already in my output, but added another at the end:

gcc weather_report.o -o weather_report -m64 -L/usr/lib/x86_64-linux-gnu/ -lcurl -L/usr/lib/x86_64-linux-gnu -Xlinker --export-dynamic -lcurl -l:libphobos2.a -lpthread -lm -lrt -lcurl

but it still complains that it cannot find -lcurl.  It even does it if I add -lcurl everywhere:

gcc weather_report.o -o weather_report -m64 -L/usr/lib/x86_64-linux-gnu/ -lcurl -L/usr/lib/x86_64-linux-gnu -Xlinker --export-dynamic -lcurl -l:libphobos2.a -lcurl -lpthread -lcurl -lm -lrt -lcurl

As an aside, I remember having to add additional mentions of a library in a link line years ago on Unix. I am surprised they haven't changed the way it works so that you only have to mention it once.

I happened to notice that among my libcurl*s

libcurl-gnutls.so.3
libcurl-gnutls.so.4
libcurl-gnutls.so.4.3.0
libcurl.so.3
libcurl.so.4
libcurl.so.4.3.0

none were just libcurl.so. So I made a link for libcurl.so to the latest version and now I am getting the same link errors I got after downloading the -dev version. So apparently my "can't find -lcurl" was because I didn't have a non-versioned libcurl.so available as it went away when I created one (and there was probably one created by the -dev download).