[Fix] `install.sh`: error out if the install instructions are not followed

README.md

@@ -203,7 +203,7 @@ If you're running a system without prepackaged binary available, which means you
 
 **Note:** On OS X, if you do not have Xcode installed and you do not wish to download the ~4.3GB file, you can install the `Command Line Tools`. You can check out this blog post on how to just that:
 
-  - [How to Install Command Line Tools in OS X Mavericks & Yosemite (Without Xcode)](http://osxdaily.com/2014/02/12/install-command-line-tools-mac-os-x/)
+  - [How to Install Command Line Tools in OS X Mavericks & Yosemite (Without Xcode)](https://osxdaily.com/2014/02/12/install-command-line-tools-mac-os-x/)
 
 **Note:** On OS X, if you have/had a "system" node installed and want to install modules globally, keep in mind that:
 
@@ -890,7 +890,7 @@ To change the user directory and/or account name follow the instructions [here](
 [3]: https://travis-ci.org/nvm-sh/nvm
 [4]: https://github.com/nvm-sh/nvm/releases/tag/v0.39.1
 [Urchin]: https://github.com/scraperwiki/urchin
-[Fish]: http://fishshell.com
+[Fish]: https://fishshell.com
 
 **Homebrew makes zsh directories unsecure**
 

install.sh

@@ -10,6 +10,12 @@ nvm_echo() {
   command printf %s\\n "$*" 2>/dev/null
 }
 
+if [ -z "${BASH_VERSION}" ] || [ -n "${ZSH_VERSION}" ]; then
+  # shellcheck disable=SC2016
+  nvm_echo >&2 'Error: the install instructions explicitly say to pipe the install script to `bash`; please follow them'
+  exit 1
+fi
+
 nvm_grep() {
   GREP_OPTIONS='' command grep "$@"
 }

nvm.sh

@@ -101,15 +101,15 @@ nvm_get_latest() {
     if nvm_curl_use_compression; then
       CURL_COMPRESSED_FLAG="--compressed"
     fi
-    NVM_LATEST_URL="$(curl ${CURL_COMPRESSED_FLAG:-} -q -w "%{url_effective}\\n" -L -s -S http://latest.nvm.sh -o /dev/null)"
+    NVM_LATEST_URL="$(curl ${CURL_COMPRESSED_FLAG:-} -q -w "%{url_effective}\\n" -L -s -S https://latest.nvm.sh -o /dev/null)"
   elif nvm_has "wget"; then
-    NVM_LATEST_URL="$(wget -q http://latest.nvm.sh --server-response -O /dev/null 2>&1 | command awk '/^  Location: /{DEST=$2} END{ print DEST }')"
+    NVM_LATEST_URL="$(wget -q https://latest.nvm.sh --server-response -O /dev/null 2>&1 | command awk '/^  Location: /{DEST=$2} END{ print DEST }')"
   else
     nvm_err 'nvm needs curl or wget to proceed.'
     return 1
   fi
   if [ -z "${NVM_LATEST_URL}" ]; then
-    nvm_err "http://latest.nvm.sh did not redirect to the latest release on GitHub"
+    nvm_err "https://latest.nvm.sh did not redirect to the latest release on GitHub"
     return 2
   fi
   nvm_echo "${NVM_LATEST_URL##*/}"

test/slow/nvm_get_latest/nvm_get_latest

@@ -10,8 +10,8 @@ cleanup() {
 
 EXPECTED_VERSION="v12.3.456"
 URL="https://github.com/nvm-sh/nvm/releases/tag/$EXPECTED_VERSION"
-EXPECTED_CURL_ARGS="--compressed -q -w %{url_effective}\n -L -s -S http://latest.nvm.sh -o /dev/null"
+EXPECTED_CURL_ARGS="--compressed -q -w %{url_effective}\n -L -s -S https://latest.nvm.sh -o /dev/null"
-EXPECTED_WGET_ARGS="-q http://latest.nvm.sh --server-response -O /dev/null"
+EXPECTED_WGET_ARGS="-q https://latest.nvm.sh --server-response -O /dev/null"
 
 curl() {
   if [ $# -eq 1 ] && [ "$1" = "-V" ]; then

test/slow/nvm_get_latest/nvm_get_latest failed redirect

@@ -17,7 +17,7 @@ wget() {
 
 OUTPUT="$(nvm_get_latest 2>&1)"
 EXIT_CODE="$(nvm_get_latest >/dev/null 2>&1 ; echo $?)"
-[ "_$OUTPUT" = "_http://latest.nvm.sh did not redirect to the latest release on GitHub" ] \
+[ "_$OUTPUT" = "_https://latest.nvm.sh did not redirect to the latest release on GitHub" ] \
   || die "failed redirect did not report correct error message, got '$OUTPUT'"
 [ "_$EXIT_CODE" = "_2" ] \
   || die "failed redirect did not exit with code 2, got $EXIT_CODE"