long getDownloadFileLenth(const char *url){
double downloadFileLenth = 0;//这里一定要是double类型,如果是long long类型获取数据有问题
CURL *handle = curl_easy_init();
curl_easy_setopt(handle, CURLOPT_URL, url);
curl_easy_setopt(handle, CURLOPT_HEADER, 1); //只需要header头
curl_easy_setopt(handle, CURLOPT_NOBODY, 1); //不需要body
if (curl_easy_perform(handle) == CURLE_OK) {
curl_easy_getinfo(handle, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &downloadFileLenth);
} else {
downloadFileLenth = -1;
}
return downloadFileLenth;
}
用上面的代码获取远程文件的大小时失败,因为远程文件的路径是
https://download.hello.com/files/hello/hello.zip
https协议的,libcurl默认是不支持https协议的,
网上传言说加上这两句可以获取大小
curl_easy_setopt(curl,CURLOPT_SSL_VERIFYPEER,false);//设定为不验证证书和HOST
curl_easy_setopt(curl,CURLOPT_SSL_VERIFYHOST,false);
我试了,没有用。
现在编译源码添加openssl的支持
静态库编译方法:
=======================================================
开始菜单进入,查找Microsoft Visual Studio 2010->Visual Studio Tools打开Visual Studio 命令提示(2010)
命令提示窗口
进入以下目录:
E:\qtproject\curl-7.58.0\winbuild>
脚本编译静态库 编译器2010
build_openssl.dat
文件内容如下:
@REM @echo off
@IF [%1]==[debug] (
@echo 正在使用debug模式编译libcurl~~~
@nmake /f Makefile.vc WITH_DEVEL=../../deps mode=static VC=10 ENABLE_IDN=no RTLIBCFG=dll DEBUG=yes MACHINE=x86
) ELSE (
@echo 正在使用release模式编译libcurl~~~
@nmake /f Makefile.vc WITH_DEVEL=../../deps mode=static VC=10 ENABLE_IDN=no RTLIBCFG=dll DEBUG=no MACHINE=x86
)
@REM @echo on
curl -V
E:\qtproject\curl-7.58.0\builds\libcurl-vc10-x86-release-static-ipv6-sspi-winssl\bin>curl -V
curl 7.58.0 (i386-pc-win32) libcurl/7.58.0 WinSSL
Release-Date: 2018-01-24
Protocols: dict file ftp ftps gopher http https imap imaps ldap pop3 pop3s rtsp
smb smbs smtp smtps telnet tftp
Features: AsynchDNS IPv6 Largefile SSPI Kerberos SPNEGO NTLM SSL
E:\qtproject\curl-7.58.0\builds\libcurl-vc10-x86-release-static-ipv6-sspi-winssl\bin>
编译成功,支持https
======================================================================================
动态库编译方法:
=======================================================
开始菜单进入,查找Microsoft Visual Studio 2010->Visual Studio Tools打开Visual Studio 命令提示(2010)
命令提示窗口
进入以下目录:
E:\qtproject\curl-7.58.0\winbuild>
脚本编译静态库 编译器2010
build_dll_openssl.dat
文件内容如下:
@REM @echo off
@IF [%1]==[debug] (
@echo 正在使用debug模式编译libcurl~~~
@nmake /f Makefile.vc WITH_DEVEL=../../deps mode=dll VC=10 ENABLE_IDN=no RTLIBCFG=dll DEBUG=yes MACHINE=x86
) ELSE (
@echo 正在使用release模式编译libcurl~~~
@nmake /f Makefile.vc WITH_DEVEL=../../deps mode=dll VC=10 ENABLE_IDN=no RTLIBCFG=dll DEBUG=no MACHINE=x86
)
@REM @echo on
编译结果:
E:\qtproject\curl-7.58.0\builds\libcurl-vc10-x86-release-dll-ipv6-sspi-winssl\bin>curl -V
curl 7.58.0 (i386-pc-win32) libcurl/7.58.0 WinSSL
Release-Date: 2018-01-24
Protocols: dict file ftp ftps gopher http https imap imaps ldap pop3 pop3s rtsp
smb smbs smtp smtps telnet tftp
Features: AsynchDNS IPv6 Largefile SSPI Kerberos SPNEGO NTLM SSL
E:\qtproject\curl-7.58.0\builds\libcurl-vc10-x86-release-dll-ipv6-sspi-winssl\bin>