How to download a file to home with C++

[shababhsiddique]

I have heard that it is possible to download a file from link using C++ wanna know how. help me downloading the simple file in C++

[/URL][url]ftp://ftp.gnu.org/pub/gnu/wget/wget-latest.tar.gz (http://3.bp.blogspot.com/_I2X40Rw3Mog/Saus9LfBVZI/AAAAAAAAABY/k2sSSJZomN4/s1600-h/seek+patience.jpg)

curl doesnot seem to download a file , it just access the html code for some reason I cant even try curl since last install, under linker settings which file should I add? libcurl.so.x.x?

I am a not very good in C++ but got the basics, try to be simple

[dwhitney67]

You should read here:
http://curl.haxx.se/libcurl/using/

And here (for programming examples):
http://curl.haxx.se/libcurl/c/example.html

Edit: Added example below...


#include <curl/curl.h>
#include <libgen.h>
#include <stdio.h>

size_t writeData(void* ptr, const size_t size, const size_t nmemb, FILE* stream)
{
return fwrite(ptr, size, nmemb, stream);
}

int main(int argc, char** argv)
{
CURL* curl = curl_easy_init();

if (curl)
{
const char* url = argv[1];
const char* filename = basename((char*)url);
FILE* ofile = fopen(filename, "wb");

if (ofile)
{
curl_easy_setopt(curl, CURLOPT_URL, url);
curl_easy_setopt(curl, CURLOPT_WRITEDATA, ofile);
curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, writeData);

curl_easy_perform(curl);

fclose(ofile);
}

/* always cleanup */
curl_easy_cleanup(curl);
}

return 0;
}

To build:


gcc getURL.c -lcurl

[shababhsiddique]

sorry for late response..
I cant get my curl work.It says xxCURLxx not found/not declared....blah blah blah...

here is how my linker looks like.

[dwhitney67]

IMO, IDEs tend to numb the mind, and hence one's progress/knowledge in the field of s/w development. Why not consider using the command line to build your applications before jumping into using code::blocks?

Nevertheless, based on the screen shot you provided, it looks like you are not specifying the library correctly. Remove the two entries you entered, and instead enter "curl", of course, without the quotes.

[s3a]

I don't know anything about this but I just wanted to add that the geany IDE (don't know about others) lets you use a built-in terminal that can automatically go to the directory of your program's files by right clicking and selecting the option. This allows for convenient usage of the "troublesome" way of doing things. (answer to the numbing the mind comment)

[shababhsiddique]

IMO, IDEs tend to numb the mind, and hence one's progress/knowledge in the field of s/w development. Why not consider using the command line to build your applications before jumping into using code::blocks?


ARE YOU SURE????? IDE to COMMAND LINE??? I AM NOT THAT GEEK ( YET!! ) I shall be pleased if you show me the path ....!.... were can I learn this thinks?? I havent got any book about it... books here seem to just stay upto "compiling from command"



Nevertheless, based on the screen shot you provided, it looks like you are not specifying the library correctly. Remove the two entries you entered, and instead enter "curl", of course, without the quotes.

Well I know that I am entering a wrong linker, I know it is curl but could not find the actual .so / .a / .lib /.bundle name.......... Plz anyone tell me what is the actual linker name and were is it located???? /lib* .. /usr/lib* .... I am new to ubuntu donno where are those stuff saved?. Entering simply "curl" or "CURL" does not work(of course without quotes! ) . consider that

[Zugzwang]

Ok, two things:

- Please copy & paste the precise error message you get. "Not declared" and "Not found" are two different things.

- Then, if just adding "curl" as a library does not work, consider this: you probably do not have have the libcurl development package installed (either libcurl4-gnutls-dev or libcurl4-openssl-dev).

[shababhsiddique]

Ok, two things:

- Please copy & paste the precise error message you get. "Not declared" and "Not found" are two different things.

- Then, if just adding "curl" as a library does not work, consider this: you probably do not have have the libcurl development package installed (either libcurl4-gnutls-dev or libcurl4-openssl-dev).

here is it

[dwhitney67]

It was suggested that you consider doing two things, yet it appears that you only did one of them.

Please, install the curl development library on your system!


sudo apt-get install libcurl4-openssl-dev


When you are done, you should be able to list the libcurl files using a typical terminal:


$ ls-l /usr/lib/libcurl*
-rw-r--r-- 1 root root 378518 2009-08-13 18:07 /usr/lib/libcurl.a
lrwxrwxrwx 1 root root 19 2009-11-12 17:18 /usr/lib/libcurl-gnutls.so.3 -> libcurl-gnutls.so.4
lrwxrwxrwx 1 root root 23 2009-11-12 17:18 /usr/lib/libcurl-gnutls.so.4 -> libcurl-gnutls.so.4.1.1
-rw-r--r-- 1 root root 256384 2009-08-13 18:07 /usr/lib/libcurl-gnutls.so.4.1.1
-rw-r--r-- 1 root root 929 2009-08-13 18:07 /usr/lib/libcurl.la
lrwxrwxrwx 1 root root 16 2010-01-18 14:11 /usr/lib/libcurl.so -> libcurl.so.4.1.1
lrwxrwxrwx 1 root root 12 2009-11-12 17:32 /usr/lib/libcurl.so.3 -> libcurl.so.4
lrwxrwxrwx 1 root root 16 2009-11-12 17:32 /usr/lib/libcurl.so.4 -> libcurl.so.4.1.1
-rw-r--r-- 1 root root 273020 2009-08-13 18:07 /usr/lib/libcurl.so.4.1.1

[shababhsiddique]

Thanks for the reply ....


I think I would restore my system . .. Is it causing from the update crash???(I have poor Internet connection here, the update error occurred a few day ago..)

[dwhitney67]

Maybe I made a mistake; maybe it is this package that you need to install: libcurl4-gnutls-dev

[shababhsiddique]

Maybe I made a mistake; maybe it is this package that you need to install: libcurl4-gnutls-dev

thanks again for the reply

Well re-installing my system solved it....! May be it was due to the update crash..

You were right curl+ libcurl4-openssl-dev was enough... anyway what is in - libcurl4-gnutls-dev? its not installed yet but still working.

Thanks again for your kind help..