surf is highly customizable, with many patches available. This build
automates some of the customizations, controlled by the following
environment variables:

PATCH
  Patch the source with patches/*.diff. Currently this includes the
  homepage, searchengines, and startfullscreen patches, which are enabled
  by default (see patches.txt for details). To build with no patches,
  use "PATCH=no".

TERMINAL
  surf runs wget in a terminal when downloading files. This must be a
  terminal emulator that supports the -e (execute command) option. Default
  is "rxvt". Other candidates: urxvt, xterm, Terminal.

HOMEPAGE
  The URL to start the browser with, if no argument given on the command
  line. Default is "https://duckduckgo.com/html/". Has no effect if
  PATCH=no.

WIDTH
HEIGHT
  The default window size for surf to use, when it starts. Default values
  are WIDTH=1280 HEIGHT=1024.

SLACKVER
  The version of Slackware you're building for. If not set, the
  version from /etc/slackware-version will be used. You only need to
  set this if building on Slackware-current (use the latest stable
  version). This is only used for the searchengines patch, so it does
  nothing if PATCH=no.

STRICTSSL
  If STRICTSSL=yes, refuse untrusted connections (e.g. invalid/unknown
  certificates). Default is no.

The values of all these variables are stored within the package, in
/usr/doc/surf-$VERSION/buildopts.sh. You can build surf again with the
same options by sourcing buildopts.sh before running surf.SlackBuild.