sudo apt-get purge winetricks

#!/bin/sh
# Create and switch to a temporary directory writeable by current user. See:
#   https://www.tldp.org/LDP/abs/html/subshells.html
cd "$(mktemp -d)" || exit 1

# Use a BASH "here document" to create an updater shell script file.
# See:
#   https://www.tldp.org/LDP/abs/html/here-docs.html
# >  outputs stdout to a file, overwriting any pre-existing file
# << takes input, directly from the script itself, till the second '_EOF_SCRIPT' marker, as stdin
# the cat command hooks these 2 streams up (stdin and stdout)
###### create update_winetricks START ########
cat > update_winetricks <<_EOF_SCRIPT
#!/bin/sh

# Create and switch to a temporary directory writeable by current user. See:
#   https://www.tldp.org/LDP/abs/html/subshells.html
cd "\$(mktemp -d)"

# Download the latest winetricks script (master="latest version") from Github.
wget https://raw.githubusercontent.com/Winetricks/winetricks/master/src/winetricks

# Mark the winetricks script (we've just downloaded) as executable. See:
#   https://www.tldp.org/LDP/GNU-Linux-Tools-Summary/html/x9543.htm
chmod +x winetricks

# Move the winetricks script to a location which will be in the standard user PATH. See:
#   https://www.tldp.org/LDP/abs/html/internalvariables.html
sudo mv winetricks /usr/bin

# Download the latest winetricks BASH completion script (master="latest version") from Github.
wget https://raw.githubusercontent.com/Winetricks/winetricks/master/src/winetricks.bash-completion

# Move the winetricks BASH completion script to a standard location for BASH completion modules. See:
#   https://www.tldp.org/LDP/abs/html/tabexpansion.html
sudo mv winetricks.bash-completion /usr/share/bash-completion/completions/winetricks

# Download the latest winetricks MAN page (master="latest version") from Github.
wget https://raw.githubusercontent.com/Winetricks/winetricks/master/src/winetricks.1

# Move the winetricks MAN page to a standard location for MAN pages. See:
#   https://www.pathname.com/fhs/pub/fhs-2.3.html#USRSHAREMANMANUALPAGES
sudo mv winetricks.1 /usr/share/man/man1/winetricks.1
_EOF_SCRIPT
###### create update_winetricks FINISH ########

# Mark the update_winetricks script (we've just written out) as executable. See:
#   https://www.tldp.org/LDP/GNU-Linux-Tools-Summary/html/x9543.htm
chmod +x update_winetricks

# We must escalate privileges to root, as regular Linux users do not have write access to '/usr/bin'.
sudo mv update_winetricks /usr/bin/

man mktemp
man mv
man wget
man sudo
...

cd "$(mktemp -d)"
cat > update_winetricks <<_EOF_SCRIPT
#!/bin/sh

cd "\$(mktemp -d)"
wget https://raw.githubusercontent.com/Winetricks/winetricks/master/src/winetricks
wget https://raw.githubusercontent.com/Winetricks/winetricks/master/src/winetricks.bash-completion
chmod +x winetricks
su root sh -c 'mv winetricks /usr/bin ; mv winetricks.bash-completion /usr/share/bash-completion/completions/winetricks'
_EOF_SCRIPT

chmod +x update_winetricks
su root sh -c 'mv update_winetricks /usr/bin/'

sudo ln "/usr/bin/update_winetricks" "/etc/cron.weekly/update_winetricks"

cd "$(mktemp -d)"
cat > winetricks_update.timer <<_EOF_TIMER_UNIT
[Unit]
Description=Run winetricks update script weekly (Saturday)

[Timer]
OnCalendar=Sat
Persistent=true

[Install]
WantedBy=timers.target
_EOF_TIMER_UNIT

cat > winetricks_update.service <<_EOF_SERVICE_UNIT
[Unit]
Description=Run winetricks update script
After=network.target

[Service]
ExecStart=/bin/sh /usr/bin/update_winetricks
Type=oneshot
_EOF_SERVICE_UNIT

sudo mv winetricks_update.timer winetricks_update.service /etc/systemd/system/

sudo systemctl daemon-reload
sudo systemctl enable winetricks_update.timer
sudo systemctl start winetricks_update.timer

winetricks --self-update

sudo winetricks --self-update

w_metadata icecat apps \
    title="GNU Icecat 38.8.0" \
    publisher="GNU Foundation" \
    year="2016" \
    media="download" \
    file1="icecat-38.8.0.en-US.win32.zip" \
    installed_exe1="${W_PROGRAMS_X86_WIN}/icecat/icecat.exe"

load_icecat()
{
    w_download https://ftp.gnu.org/gnu/gnuzilla/38.8.0/${file1} e5f9481e78710c25eb3a271d81aceb19ef44ff6e8599da7d5f7a2da584c01213
    w_try_unzip "${W_PROGRAMS_X86_UNIX}" "${W_CACHE}/${W_PACKAGE}/${file1}"
}