PAC function reference

The functions a PAC file can call, what they really do, and which engines provide them. Availability is derived from the engines' own helper libraries, not from documentation.

Standard (Netscape) functions

• isPlainHostName(host)

  True if the host name contains no domain part (no dot), e.g. "intranet".

• dnsDomainIs(host, domain)

  True if host ends with domain. A plain string suffix comparison, no DNS lookup.

• localHostOrDomainIs(host, hostdom)

  True if host equals hostdom exactly, or host is the unqualified first label of hostdom.

• isResolvable(host)

  True if the host name resolves in DNS. Performs a blocking DNS lookup.

• isInNet(host, pattern, mask)

  True if the IP address of host is in the network pattern/mask. Resolves host via DNS if it is not an IP literal.

• dnsResolve(host)

  Resolves a host name to an IP address string, or null. Performs a blocking DNS lookup.

• myIpAddress()

  Returns an IP address of the machine running the PAC. Which address you get is engine-specific.

• dnsDomainLevels(host)

  Number of dots in the host name ("www.corp.example" gives 2).

• shExpMatch(str, pattern)

  Shell-glob match of str against pattern; * matches any sequence, ? one character. The whole string must match.

• weekdayRange(wd1 [, wd2] [, "GMT"])

  True on the given weekday or within the weekday range (SUN, MON, ... SAT). Local time unless "GMT" is passed.

• dateRange(day | month | year ... [, "GMT"])

  True if the current date is within the given day, month and/or year range.

• timeRange(hour | hour, min | hour, min, sec ... [, "GMT"])

  True if the current time is within the given hour/minute/second range.

Microsoft IPv6 extensions (*Ex)

• dnsResolveEx(host)

  Microsoft IPv6 extension. Returns a semicolon-separated list of IPv4 and IPv6 addresses, or an empty string.

• myIpAddressEx()

  Microsoft IPv6 extension. Semicolon-separated list of the machine's addresses.

• isResolvableEx(host)

  Microsoft IPv6 extension. True if the host resolves to any IPv4 or IPv6 address.

• isInNetEx(ip, prefix)

  Microsoft IPv6 extension. True if ip is inside the CIDR prefix, e.g. isInNetEx(ip, "2001:db8::/32").

• sortIpAddressList(list)

  Microsoft IPv6 extension. Sorts a semicolon-separated IP address list.

Debugging

• alert(message)

  Debug output from a PAC. Where it goes depends on the engine; remove it from production files.

Availability by engine