Linux – Delphi cross compiler for linux

From this news group posting by Mark Zbikowski himself:

The differences between .CMD and .BAT as far as CMD.EXE is concerned are: With extensions enabled, PATH/APPEND/PROMPT/SET/ASSOC in .CMD files will set ERRORLEVEL regardless of error. .BAT sets ERRORLEVEL only on errors.

In other words, if ERRORLEVEL is set to non-0 and then you run one of those commands, the resulting ERRORLEVEL will be:

• left alone at its non-0 value in a .bat file
• reset to 0 in a .cmd file.

The simplest and most widely available method to get user input at a shell prompt is the read command. The best way to illustrate its use is a simple demonstration:

while true; do
    read -p "Do you wish to install this program?" yn
    case $yn in
        [Yy]* ) make install; break;;
        [Nn]* ) exit;;
        * ) echo "Please answer yes or no.";;
    esac
done

Another method, pointed out by Steven Huwig, is Bash's select command. Here is the same example using select:

echo "Do you wish to install this program?"
select yn in "Yes" "No"; do
    case $yn in
        Yes ) make install; break;;
        No ) exit;;
    esac
done

With select you don't need to sanitize the input – it displays the available choices, and you type a number corresponding to your choice. It also loops automatically, so there's no need for a while true loop to retry if they give invalid input.

Also, Léa Gris demonstrated a way to make the request language agnostic in her answer. Adapting my first example to better serve multiple languages might look like this:

set -- $(locale LC_MESSAGES)
yesptrn="$1"; noptrn="$2"; yesword="$3"; noword="$4"

while true; do
    read -p "Install (${yesword} / ${noword})? " yn
    if [[ "$yn" =~ $yesexpr ]]; then make install; exit; fi
    if [[ "$yn" =~ $noexpr ]]; then exit; fi
    echo "Answer ${yesword} / ${noword}."
done

Obviously other communication strings remain untranslated here (Install, Answer) which would need to be addressed in a more fully completed translation, but even a partial translation would be helpful in many cases.

Finally, please check out the excellent answer by F. Hauri.