Modified URL resolution method

build-dektec-dkms

@@ -40,7 +40,6 @@ INSTALL=false
 export KEEP=false
 PREPARE_ONLY=false
 UNINSTALL=false
-URL="https://www.dektec.com/products/SDK/DTAPI/Downloads/LatestLinuxSDK"
 VERBOSE=false
 PATCH_OPTION="--silent"
 
@@ -94,11 +93,6 @@ Options:
       uninstall a package. This is useful on unsupported systems (no .rpm,
       no .deb).
 
-  -u "url"
-  --url "url"
-     URL of the Dektec LinuxSDK. Default:
-     $URL
-
   -v
   --verbose
       Display verbose information.
@@ -151,10 +145,6 @@ while [[ $# -gt 0 ]]; do
         --uninstall)
             UNINSTALL=true
             ;;
-        -u|--url)
-            [[ $# -gt 1 ]] || usage; shift
-            URL=$1
-            ;;
         -v|--verbose)
             VERBOSE=true
             PATCH_OPTION=
@@ -172,11 +162,7 @@ DTAPI_H="$SDKDIR/DTAPI/Include/DTAPI.h"
 PKGDIR="$SCRIPTDIR/packages"
 export TMPDIR="$SCRIPTDIR/tmp"
 
-# The download URL is a generic one ending in ../LatestLinuxSDK.
-# The actual file is redirected as ../LinuxSDK_v5.06.2017.0.tar.gz for instance.
-# The file VERSION is created to contain the actual file name.
-
-TARBASE="$SCRIPTDIR/LinuxSDK"
+# Text file containing the name of the LinuxSDK tarball.
 VERSFILE="$SCRIPTDIR/VERSION"
 
 #-----------------------------------------------------------------------------
@@ -185,7 +171,7 @@ VERSFILE="$SCRIPTDIR/VERSION"
 
 if $CLEAN; then
     verbose "cleaning up non-original files"
-    rm -rf "${TARBASE}*" "$SDKDIR" "$TMPDIR" "$VERSFILE"
+    rm -rf "$SCRIPTDIR"/LinuxSDK* "$SDKDIR" "$TMPDIR" "$VERSFILE"
     cleanexit 0
 fi
 
@@ -194,20 +180,18 @@ fi
 #-----------------------------------------------------------------------------
 
 # Download the LinuxSDK if not present.
-[[ -n "$URL" ]] || error "empty URL specified"
 TARNAME=$(cat "$VERSFILE" 2>/dev/null)
 TARBALL="$SCRIPTDIR/$TARNAME"
 if $FORCE || [[ -z "$TARNAME" ]] || [[ ! -e "$TARBALL" ]]; then
+    URL=$($SCRIPTDIR/get-dektec-linux-sdk-url.sh)
+    [[ -n "$URL" ]] || error "got empty URL"
     verbose "downloading $URL"
     mkdir -p "$TMPDIR"
-    # Do not download/redirect, just get the HTTP headers
-    curl -D "$TMPDIR/HEADERS" "$URL" || cleanexit 1
-    TARNAME=$(grep -i Location: "$TMPDIR/HEADERS" | sed -e 's/.*: *//' -e 's/.*\///' -e 's/\r//g')
+    TARNAME=$(basename "$URL")
     TARBALL="$SCRIPTDIR/$TARNAME"
-    [[ -n "$TARNAME" ]] || error "relocation header not found"
     verbose "actual file name: $TARNAME"
     echo "$TARNAME" >"$VERSFILE"
-    curl -L "$URL" -o "$TARBALL" || cleanexit 1
+    curl --location "$URL" -o "$TARBALL" || cleanexit 1
 fi
 
 # Get the Linux SDL version from the file name.

get-dektec-linux-sdk-url.sh

@@ -0,0 +1,89 @@
+#!/bin/bash
+#-----------------------------------------------------------------------------
+#
+#  TSDuck - The MPEG Transport Stream Toolkit
+#  Copyright (c) 2005-2018, Thierry Lelegard
+#  All rights reserved.
+#
+#  Redistribution and use in source and binary forms, with or without
+#  modification, are permitted provided that the following conditions are met:
+#
+#  1. Redistributions of source code must retain the above copyright notice,
+#     this list of conditions and the following disclaimer.
+#  2. Redistributions in binary form must reproduce the above copyright
+#     notice, this list of conditions and the following disclaimer in the
+#     documentation and/or other materials provided with the distribution.
+#
+#  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+#  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+#  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+#  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+#  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+#  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+#  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+#  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+#  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+#  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+#  THE POSSIBILITY OF SUCH DAMAGE.
+#
+#-----------------------------------------------------------------------------
+#
+#  This script retrieves the URL of the latest LinuSDK from Dektec.
+#
+#-----------------------------------------------------------------------------
+
+URL_BASE=https://www.dektec.com
+HTML_URL=$URL_BASE/downloads/SDK/
+GENERIC_URL=$URL_BASE/products/SDK/DTAPI/Downloads/LatestLinuxSDK
+
+SCRIPT=$(basename $BASH_SOURCE)
+error() { echo >&2 "$SCRIPT: $*"; exit 1; }
+
+# Merge an URL with its base.
+merge_url()
+{
+    local ref="$1"
+    local url
+    read url
+
+    if [[ -n "$url" ]]; then
+        if [[ $url == *:* ]]; then
+            echo "$url"
+        elif [[ $url == /* ]]; then
+            echo "$URL_BASE$url"
+        elif [[ $ref == */ ]]; then
+            echo "$ref$url"
+        else
+            ref=$(dirname "$ref")
+            echo "$ref/$url"
+        fi
+    fi
+}
+
+# Retrieve the URL using the redirection from a fixed generic URL.
+# This should be the preferred method but Dektec may forget to update
+# the redirection in the generic URL.
+from_generic_url()
+{
+    curl --silent --show-error --dump-header /dev/stdout "$GENERIC_URL" | \
+        grep -i 'Location:' | \
+        sed -e 's/.*: *//' -e 's/\r//g' | \
+        merge_url "$GENERIC_URL"
+}
+
+# Retrieve the URL by parsing the HTML from the Dektec download web page.
+from_html_page()
+{
+    curl --silent --show-error --location "$HTML_URL" | \
+        grep 'href=".*LinuxSDK' | \
+        sed -e 's/.*href="//' -e 's/".*//' | \
+        merge_url "$HTML_URL"
+}
+
+# Try the HTML parsing first, then redirection.
+URL=$(from_html_page)
+[[ -z "$URL" ]] && URL=$(from_generic_url)
+[[ -z "$URL" ]] && error "cannot locate LinuxSDK location from Dektec"
+
+echo "$URL"
+exit 0