#!/bin/sh
target=~/.gitconfig
if [ -z "$OVERWRITE_GITCONFIG" ] && [ -e "$target" ]
then
  exit
fi

user=$(id -un)                                   || exit
[ "$user" ]                                      || exit
email=${user}@$(hostname --fqdn)                 || exit
[ "$email" ]                                     || exit
name=$(getent passwd "$user" | cut -d: -f2)      || : ok
temp=$(mktemp ~/.gitconfig.tmp.XXX)              || exit
[ "$temp" ]                                      || exit

gitconfig()
{
cat <<END
[user]
        email = ${email}
        name = ${name:-$email}
[core]
        excludesfile = ~/.config/git/ignore
END
}

gitconfig > "$temp" &&
  mv "$temp" "$target" ||
    rm -f "$temp"