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@cubedtear
Last active July 7, 2023 04:37
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Self-updating bash script
#!/usr/bin/env bash
VERSION="0.0.2"
SCRIPT_URL='https://gist.github.com/cubedtear/54434fc66439fc4e04e28bd658189701/raw'
SCRIPT_DESCRIPTION=""
SCRIPT_LOCATION="${BASH_SOURCE[@]}"
rm -f updater.sh
function update()
{
TMP_FILE=$(mktemp -p "" "XXXXX.sh")
curl -s -L "$SCRIPT_URL" > "$TMP_FILE"
NEW_VER=$(grep "^VERSION" "$TMP_FILE" | awk -F'[="]' '{print $3}')
ABS_SCRIPT_PATH=$(readlink -f "$SCRIPT_LOCATION")
if [ "$VERSION" \< "$NEW_VER" ]
then
printf "Updating script \e[31;1m%s\e[0m -> \e[32;1m%s\e[0m\n" "$VERSION" "$NEW_VER"
echo "cp \"$TMP_FILE\" \"$ABS_SCRIPT_PATH\"" > updater.sh
echo "rm -f \"$TMP_FILE\"" >> updater.sh
echo "echo Running script again: `basename ${BASH_SOURCE[@]}` $@" >> updater.sh
echo "exec \"$ABS_SCRIPT_PATH\" \"$@\"" >> updater.sh
chmod +x updater.sh
chmod +x "$TMP_FILE"
exec updater.sh
else
rm -f "$TMP_FILE"
fi
}
update "$@"
echo "$@"
@andreas-becker
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andreas-becker commented Nov 2, 2021

SCRIPT_DESCRIPTION is unused and could be removed
${BASH_SOURCE[@]} double quote array expansions to avoid re-splitting elements

@cubedtear
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Author

SCRIPT_DESCRIPTION is unused and could be removed

It is intended as a placeholder in order to remember to describe the scripts usage. A comment would be enough, but they are easily forgotten.

@hueyvle
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hueyvle commented Jul 7, 2023

Thanks for a very good script.
I have a few suggestions tho.

  1. add a check for curl
    which curls > /dev/null 2>&1 || echo "curl not found"

  2. check for curl download failure and add logic to skip if there is no internet connection
    curl --connect-timeout 5 ....

  3. Your version comparison would fail: ie.
    "1.10.1" < "1.2.1" will return true, when it is not.
    There are a few technique to compare versions on the internet. just google it.

  4. update.sh is hardcoded too many times. puting it in a local variable would be better.

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