How to compile a program with static libcurl?

Question

There is a following code:

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

int main(void){
  CURL *curl;
  CURLcode res;

  curl = curl_easy_init();

  if(curl == NULL)
    return 0;

  curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/getAccessAttributes?id=1");

  res = curl_easy_perform(curl);

  if(res != CURLE_OK) {
    fprintf(stderr, "Error: %s\n", curl_easy_strerror(res));
    return 0;
  }

  curl_easy_cleanup(curl);
  return 0;
}

Everything works fine if you collect it from the dynamic link library:

gcc test.c -lcurl -o test

Now I want to raise a static program:

gcc test.c /tmp/curl/lib/libcurl.a -static -lcurl -lssl -lcrypto -ldl -lm -lz -DCURL_STATICLIB -I/tmp/curl/include -o test

He is going with errors:

/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../x86_64-linux-gnu/libcrypto.a(dso_dlfcn.o): In function dlfcn_globallookup': (.text+0x11): warning: Using 'dlopen' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking /tmp/curl/lib/libcurl.a(libcurl_la-netrc.o): In functionCurl_parsenetrc': netrc.c:(.text+0x3c8): warning: Using 'getpwuid_r' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking /tmp/curl/lib/libcurl.a(libcurl_la-curl_addrinfo.o): In function `Curl_getaddrinfo_ex': curl_addrinfo.c:(.text+0x60): warning: Using 'getaddrinfo' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking

The program works only if you specify a host ip address and not example.com. Otherwise the program can not resolve the domain name:

$ ./test
Error: Couldn't resolve host name

How can I solve the problem of name resolution? Thanks!

P.S. Static libcurl I collected the following method:

wget http://curl.haxx.se/download/curl-7.44.0.tar.lzma
tar xf curl-7.44.0.tar.lzma
cd curl-7.44.0
./configure --disable-shared --enable-static --prefix=/tmp/curl --disable-ldap --disable-sspi --without-librtmp --disable-ftp --disable-file --disable-dict --disable-telnet --disable-tftp --disable-rtsp --disable-pop3 --disable-imap --disable-smtp --disable-gopher --disable-smb --without-libidn
make && make install

Answer 1

This is how it looks with dynamic libcurl.

$ ldd test
    linux-vdso.so.1 (0x00007ffcca3aa000)
    libcurl.so.4 => /usr/lib64/libcurl.so.4 (0x00007f5536ed6000)
    libc.so.6 => /lib64/libc.so.6 (0x00007f5536b3e000)
    libssl.so.1.0.0 => /usr/lib64/libssl.so.1.0.0 (0x00007f55368d3000)
    libcrypto.so.1.0.0 => /usr/lib64/libcrypto.so.1.0.0 (0x00007f5536503000)
    libz.so.1 => /lib64/libz.so.1 (0x00007f55362ed000)
    /lib64/ld-linux-x86-64.so.2 (0x00007f5537138000)
    libdl.so.2 => /lib64/libdl.so.2 (0x00007f55360e9000)

If you want to link only curl statically, do not use -static. Just add libcurl.a as one of the objects files or use -lcurl, you don't need to specify it twice. After

gcc test.c curl-7.44.0/lib/.libs/libcurl.a -lssl -lcrypto -ldl -lm -lz -DCURL_STATICLIB -o test

you'll get

$ ldd test
    linux-vdso.so.1 (0x00007ffd9a0a7000)
    libssl.so.1.0.0 => /usr/lib64/libssl.so.1.0.0 (0x00007f947cc7e000)
    libcrypto.so.1.0.0 => /usr/lib64/libcrypto.so.1.0.0 (0x00007f947c8ae000)
    libdl.so.2 => /lib64/libdl.so.2 (0x00007f947c6aa000)
    libm.so.6 => /lib64/libm.so.6 (0x00007f947c3b1000)
    libz.so.1 => /lib64/libz.so.1 (0x00007f947c19b000)
    libc.so.6 => /lib64/libc.so.6 (0x00007f947be03000)
    /lib64/ld-linux-x86-64.so.2 (0x00007f947cee9000)

-static means that you want link all statically. Then you need all libraries prepared as static and the result will be:

$ ldd test
    not a dynamic executable

Answer 2

I found a way. libcurl must be configured with key "--enable-ares".

./configure --disable-shared --enable-static --prefix=/tmp/curl --disable-ldap --disable-sspi --without-librtmp --disable-ftp --disable-file --disable-dict --disable-telnet --disable-tftp --disable-rtsp --disable-pop3 --disable-imap --disable-smtp --disable-gopher --disable-smb --without-libidn --enable-ares

Then the program will feature gethostbyname and will be able to resolve the domain name.

Thank you all for the comments.