现在浏览器基本都支持PAC格式的代理脚本。本文仅介绍PAC脚本语法,并不解释使用方法。
示例脚本
function FindProxyForURL(url, host) {
// our local URLs from the domains below example.com don't need a proxy:
if (shExpMatch(host, "*.example.com")) {
return "DIRECT";
}
// URLs within this network are accessed through
// port 8080 on fastproxy.example.com:
if (isInNet(host, "10.0.0.0", "255.255.248.0")) {
return "PROXY fastproxy.example.com:8080";
}
// All other requests go through port 8080 of proxy.example.com.
// should that fail to respond, go directly to the WWW:
return "PROXY proxy.example.com:8080; DIRECT";
}
主体
PAC脚本主体是一个FindProxyForURL的JS函数。函数的反回值有三类:
function FindProxyForURL(url,host) {
if(host=="http://www.domain.com/") return "DIRECT";
return "PROXY myproxy:80;PROXY myotherproxy:8080;DIRECT";
}
函数
isPlainHostName(host)
判断是否是本地主机
dnsDomainIs(host,domain) localHostOrDomainIs(host,"")
判断访问主机是否属于某个域和某个域名
示例:
function FindProxyForURL(url, host) {
if ((isPlainHostName(host) ||
dnsDomainIs(host, ".company.com")) &&
!localHostOrDomainIs(host, "http://www.company.com/") &&
!localHostOrDomainIs(host, "home.company.com"))
return "DIRECT";
else
return "PROXY proxy:80";
}
isResolvable(host)
主机名是否能被dns服务器解析
示例:
function FindProxyForURL(url, host) {
if (isResolvable(host))
return "DIRECT";
else
return "PROXY proxy:80";
}
isInNet(host,"","")
访问IP是否在某个子网内
shExpMatch(host,"")
主机名判断
示例:
function FindProxyForURL(url, host) {
if (isPlainHostName(host))
return "DIRECT";
else if (shExpMatch(host, "*.com"))
return "PROXY comproxy:80";
else if (shExpMatch(host, "*.edu"))
return "PROXY eduproxy:80";
else
return "PROXY proxy:80";
}
url.substring(0,n)
截取协议字符串
示例:
function FindProxyForURL(url, host) {
if (url.substring(0, 5) == "http:") {
return "PROXY proxy:80";
}
else if (url.substring(0, 4) == "ftp:") {
return "PROXY fproxy:80";
}
else if (url.substring(0, 7) == "gopher:") {
return "PROXY gproxy";
}
else if (url.substring(0, 6) == "https:") {
return "PROXY secproxy:8080";
} else {
return "DIRECT";
}
}
dnsResolve(host)
域名ip解析
示例:
function FindProxyForURL(url, host) {
if (dnsResolve(host) == "166.111.8.237") {
return "PROXY secproxy:8080";
} else {
return "PROXY proxy:80";
}
}
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