Read user input properly in linux_install.sh for Gentoo (#4395)

* Change spaces to tabs on two lines

The rest of the file uses tabs

* Read user input in a non-terrible, non-hacky way

* Remove unnecessary tee call

* read -p is not POSIX

* Add missing $ to echo GENTOO_WARNING

* Replace non-POSIX echo -n with printf

* Use cd ... || exit 1 in case git clone fails

* Add missing sudo

Thanks @snortwolf

* Undo replacing tee with >>

1 files changed, 8 insertions, 10 deletions

diff --git a/util/linux_install.sh b/util/linux_install.sh
index 70b389c0d..d6e6b86cd 100755
--- a/util/linux_install.sh
+++ b/util/linux_install.sh
@@ -32,7 +32,7 @@ if grep ID /etc/os-release | grep -qE "fedora"; then
 elif grep ID /etc/os-release | grep -qE 'debian|ubuntu'; then
         DEBIAN_FRONTEND=noninteractive
         DEBCONF_NONINTERACTIVE_SEEN=true
-        export DEBIAN_FRONTEND DEBCONF_NONINTERACTIVE_SEEN
+        export DEBIAN_FRONTEND DEBCONF_NONINTERACTIVE_SEEN
         sudo apt-get update
         sudo apt-get install \
                 build-essential \
@@ -70,20 +70,18 @@ elif grep ID /etc/os-release | grep -q 'arch\|manjaro'; then
                 wget \
                 zip
         git clone https://aur.archlinux.org/dfu-programmer.git /tmp/dfu-programmer
-        cd /tmp/dfu-programmer
+        cd /tmp/dfu-programmer || exit 1
         makepkg -sic
         rm -rf /tmp/dfu-programmer/
 
 elif grep ID /etc/os-release | grep -q gentoo; then
-        echo GENTOO_WARNING | fmt
-        echo -n "Proceed (y/N)? "
-        old_stty_cfg=$(stty -g)
-        stty raw -echo
-        answer=$( while ! head -c 1 | grep -i '[ny]' ;do true ;done )
-        stty $old_stty_cfg
-        if echo "$answer" | grep -iq "^y" ;then
+        echo "$GENTOO_WARNING" | fmt
+        printf "\nProceed (y/N)? "
+        read -r answer
+        if echo "$answer" | grep -iq "^y"; then
                 sudo touch /etc/portage/package.use/qmkfirmware
-                echo "sys-devel/gcc multilib" | sudo tee --append /etc/portage/package.use/qmkfirmware > /dev/null
+                # tee is used here since sudo doesn't apply to >>
+                echo "sys-devel/gcc multilib" | sudo tee --append /etc/portage/package.use/qmkfirmware >/dev/null
                 sudo emerge -auN \
                         app-arch/unzip \
                         app-arch/zip \