Fail if curl call fails (#276)

* Yay HTTPS on erlang.org!

* issue-275: fail if curl fails

* issue-275: forgot to remove tmp curled file

2 files changed, 18 insertions, 9 deletions

diff --git a/README.md b/README.md
index e94ad16..cde4550 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,7 @@
 kerl [![TravisCI build status](https://travis-ci.org/kerl/kerl.svg?branch=master)](https://travis-ci.org/kerl/kerl) [![CircleCI](https://circleci.com/gh/kerl/kerl.svg?style=svg)](https://circleci.com/gh/kerl/kerl)
 ====
 
-Easy building and installing of [Erlang/OTP](http://www.erlang.org) instances.
+Easy building and installing of [Erlang/OTP](https://www.erlang.org) instances.
 
 Kerl aims to be shell agnostic and its only dependencies, excluding what's
 required to actually build Erlang/OTP, are `curl` and `git`.
@@ -57,7 +57,7 @@ Kerl keeps tracks of the releases it downloads, builds and installs, allowing
 easy installations to new destinations (without complete rebuilding) and easy
 switches between Erlang/OTP installations.
 
-By default, kerl downloads source tarballs from the [official Erlang website](http://www.erlang.org), but
+By default, kerl downloads source tarballs from the [official Erlang website](https://www.erlang.org), but
 you can tell kerl to download tarballs of Erlang source code from the tags
 pushed to the [official source code](https://github.com/erlang/otp) by setting `KERL_BUILD_BACKEND=git`
 
@@ -380,7 +380,7 @@ Glossary
 
 Here are the abstractions kerl is handling:
 
-- **releases**: Erlang/OTP releases from [erlang.org](http://erlang.org)
+- **releases**: Erlang/OTP releases from [erlang.org](https://erlang.org)
 
 - **builds**: the result of configuring and compiling releases or git repositories
 
@@ -406,7 +406,7 @@ Creates a named build either from an official Erlang/OTP release or from a git r
 You can specify the configure options to use when building Erlang/OTP with the
 `KERL_CONFIGURE_OPTIONS` variable, either in your $HOME/.kerlrc file or
 prepending it to the command line.  Full list of all options can be in
-[Erlang documentation](http://erlang.org/doc/installation_guide/INSTALL.html#Advanced-configuration-and-build-of-ErlangOTP_Configuring).
+[Erlang documentation](https://erlang.org/doc/installation_guide/INSTALL.html#Advanced-configuration-and-build-of-ErlangOTP_Configuring).
 
     $ KERL_CONFIGURE_OPTIONS=--enable-hipe kerl build 19.2 19.2-hipe
 
diff --git a/kerl b/kerl
index e561866..27906f3 100755
--- a/kerl
+++ b/kerl
@@ -27,7 +27,7 @@ unset ERL_TOP
 KERL_VERSION='1.8.2'
 
 DOCSH_GITHUB_URL='https://github.com/erszcz/docsh.git'
-ERLANG_DOWNLOAD_URL='http://www.erlang.org/download'
+ERLANG_DOWNLOAD_URL='https://www.erlang.org/download'
 KERL_CONFIG_STORAGE_FILENAME='.kerl_config'
 
 if [ -z "$HOME" ]; then
@@ -211,10 +211,19 @@ get_git_releases() {
 }
 
 get_tarball_releases() {
-    curl -f -q -L -s $ERLANG_DOWNLOAD_URL/ | \
-        sed $SED_OPT -e 's/^.*<[aA] [hH][rR][eE][fF]=\"otp_src_([-0-9A-Za-z_.]+)\.tar\.gz\">.*$/\1/' \
-                     -e '/^R1|^[0-9]/!d' | \
-        sed -e 's/^R\(.*\)/\1:R\1/' | sed -e 's/^\([^\:]*\)$/\1-z:\1/' | sort | cut -d: -f2
+    tmp="$(mktemp /tmp/kerl.XXXXXX)"
+    if [ 200 = "$(curl -qsL --output "$tmp" --write-out '%{http_code}' $ERLANG_DOWNLOAD_URL/)" ]; then
+        sed $SED_OPT \
+            -e 's/^.*<[aA] [hH][rR][eE][fF]=\"otp_src_([-0-9A-Za-z_.]+)\.tar\.gz\">.*$/\1/' \
+            -e '/^R1|^[0-9]/!d' "$tmp" \
+        | sed -e 's/^R\(.*\)/\1:R\1/' \
+        | sed -e 's/^\([^\:]*\)$/\1-z:\1/' \
+        | sort | cut -d: -f2
+        rm "$tmp"
+        return 0
+    fi
+    rm "$tmp"
+    exit 1
 }
 
 update_checksum_file() {