CentOS7 PHP cURL errno 35, 原因：CentOS7中没有安装curl和OpenSSL的最新版

安装OpenSSL的最新版

话不多说，直接上安装步骤

#cd /usr/local/src
# 跳过证书获取失败
# wget https://www.openssl.org/source/openssl-1.0.2n.tar.gz --no-check-certificate
# tar xzvf openssl-1.0.2n.tar.gz
# cd openssl-1.0.2n
# ./config shared enable-ssl2 enable-ssl3 --prefix=/usr
# make depend
# make
# #确认没有错误
# make test
# make install
# #如果顺利的话就好了
# openssl version

进展顺利

安装curl的最新版

这里也大体上就那样,不过，因为wget curl的文件的时候，SSL通信用其他的方法取得

# cd /usr/local/src
# #如果wget不能用其他的方法下载
# wget https://curl.haxx.se/download/curl-7.58.0.tar.gz
# tar xzvf curl-7.58.0.tar.gz
# cd curl-7.58.0
# ./configure --enable-libcurl-option --with-ssl=/usr --prefix=/usr

./confirure 的输出结果的一部分如下：

--如果弄错with-ssl的目录指定，SSL support的部分变成no。
--libcurl option:也确认一下是enabled吧。

configure: Configured to build curl/libcurl:

  curl version:     7.58.0
  Host setup:       x86_64-pc-linux-gnu
  Install prefix:   /usr
  Compiler:         gcc
  SSL support:      enabled (OpenSSL)
  SSH support:      no      (--with-libssh2)
  zlib support:     enabled
  brotli support:   no      (--with-brotli)
  GSS-API support:  no      (--with-gssapi)
  TLS-SRP support:  enabled
  resolver:         POSIX threaded
  IPv6 support:     enabled
  Unix sockets support: enabled
  IDN support:      no      (--with-{libidn2,winidn})
  Build libcurl:    Shared=yes, Static=yes
  Built-in manual:  enabled
  --libcurl option: enabled (--disable-libcurl-option)
  Verbose errors:   enabled (--disable-verbose)
  SSPI support:     no      (--enable-sspi)
  ca cert bundle:   /etc/pki/tls/certs/ca-bundle.crt
  ca cert path:     no
  ca fallback:      no
  LDAP support:     enabled (OpenLDAP)
  LDAPS support:    enabled
  RTSP support:     enabled
  RTMP support:     no      (--with-librtmp)
  metalink support: no      (--with-libmetalink)
  PSL support:      no      (libpsl not found)
  HTTP2 support:    disabled (--with-nghttp2)
  Protocols:        DICT FILE FTP FTPS GOPHER HTTP HTTPS IMAP IMAPS LDAP LDAPS POP3 POP3S RTSP SMB SMBS SMTP SMTPS TELNET TFTP

然后 make

# make

中途输出Warning: compression requested but Gzip is not available，这次没有通过！好像在hugehelp.c上输出了什么，应该不是严重的错误……？

然后 make install

# make install

下面显示输出结果的一部分。

 /bin/sh ../libtool   --mode=install /usr/bin/install -c   libcurl.la '/usr/lib'
libtool: install: /usr/bin/install -c .libs/libcurl.so.4.5.0 /usr/lib/libcurl.so.4.5.0

(略)

----------------------------------------------------------------------
Libraries have been installed in:
   /usr/lib

If you ever happen to want to link against installed libraries
in a given directory, LIBDIR, you must either use libtool, and
specify the full pathname of the library, or use the '-LLIBDIR'
flag during linking and do at least one of the following:
   - add LIBDIR to the 'LD_LIBRARY_PATH' environment variable
     during execution
   - add LIBDIR to the 'LD_RUN_PATH' environment variable
     during linking
   - use the '-Wl,-rpath -Wl,LIBDIR' linker flag
   - have your system administrator add LIBDIR to '/etc/ld.so.conf'

See any operating system documentation about shared libraries for
more information, such as the ld(1) and ld.so(8) manual pages.
----------------------------------------------------------------------

安装好了， curl -V 不过有错误。

curl: error while loading shared libraries: libcurl.so.4: cannot open shared object file: No such file or directory

好像无法读取库。

如果用ldd /usr/bin/curl确认的话，确实没有libcurl.so.4 =>的参照处。但是make install的时候/usr/lib/libcurl.so.4.5.0上写着安装了。

用共享库就好。（http://www.8wave.net/ldconfig.html）

# # 在末尾添加“/usr/lib”
# vim /etc/ld.so.conf.d/lib.conf
# ldconfig

这样就OK了。

curl -V

输出结果

curl 7.58.0 (x86_64-pc-linux-gnu) libcurl/7.58.0 OpenSSL/1.0.2n zlib/1.2.3
Release-Date: 2018-01-24
Protocols: dict file ftp ftps gopher http https imap imaps ldap ldaps pop3 pop3s rtsp smb smbs smtp smtps telnet tftp 
Features: AsynchDNS IPv6 Largefile NTLM NTLM_WB SSL libz TLS-SRP UnixSockets HTTPS-proxy 

大功告成！