CentOS7 curl版本升级过程

curl 7.19.7 (x86_64-redhat-linux-gnu) libcurl/7.19.7 nss/3.21 basic ecc zlib/1.2.3 libidn/1.18 libssh2/1.4.2
protocols: tftp ftp telnet dict ldap ldaps http file https ftps scp sftp
features: gss-negotiate idn ipv6 largefile ntlm ssl libz

 首先备份一下：
#cp /etc/pki/tls/certs/ca-bundle.crt /etc/pki/tls/certs/ca-bundle.crt.bak
更新并替换：
#curl http://curl.haxx.se/ca/cacert.pem -o /etc/pki/tls/certs/ca-bundle.crt

新增 repo：
vim /etc/yum.repos.d/city-fan-for-curl.repo
centos6 编辑为如下：

[cityfanforcurl]
name=city fan repo
baseurl=http://www.city-fan.org/ftp/contrib/yum-repo/rhel6/x86_64/
enabled=0
gpgcheck=0

[cityfanforcurl]
name=city fan repo
baseurl=http://www.city-fan.org/ftp/contrib/yum-repo/rhel7/x86_64/
enabled=0
gpgcheck=0

yum update curl --enablerepo=cityfanforcurl -y

# curl --version 

curl 7.53.1 (x86_64-redhat-linux-gnu) libcurl/7.53.1 openssl/1.0.1e zlib/1.2.3 c-ares/1.12.0 libssh2/1.8.0 nghttp2/1.6.0