O script do shell gera um erro não encontrado quando executado a partir de um arquivo sh. Mas se digitados manualmente, os comandos funcionam

Estou tentando usar o script a seguir para gerar um mapa do site para o meu site. Quando o executo, sh thsitemap.shrecebo um erro como esse e cria um arquivo sitemap.xml vazio:

thsitemap.sh: 22: thsitemap.sh: [[: not found
thsitemap.sh: 42: thsitemap.sh: [[: not found
thsitemap.sh: 50: thsitemap.sh: Syntax error: "(" unexpected

Mas como o mesmo usuário rootquando copio e colo manualmente essas linhas no terminal, ele funciona sem nenhum erro e o arquivo sitemap.xml possui todos os URLs. Qual é o problema? Como posso consertar isso?

#!/bin/bash
##############################################
# modified version of original http://media-glass.es/ghost-sitemaps/
# for ghost.centminmod.com
# http://ghost.centminmod.com/ghost-sitemap-generator/
##############################################
url="techhamlet.com"
webroot='/home/leafh8kfns/techhamlet.com'
path="${webroot}/sitemap.xml"
user='leafh8kfns'       # web server user
group='leafh8kfns'      # web server group

debug='n' # disable debug mode with debug='n'
##############################################
date=`date +'%FT%k:%M:%S+00:00'`
freq="daily"
prio="0.5"
reject='.rss, .gif, .png, .jpg, .css, .js, .txt, .ico, .eot, .woff, .ttf, .svg, .txt'
##############################################
# create sitemap.xml file if it doesn't exist and give it same permissions
# as nginx server user/group
if [[ ! -f "$path" ]]; then
    touch $path
    chown ${user}:${group} $path
fi

# check for robots.txt defined Sitemap directive
# if doesn't exist add one
# https://support.google.com/webmasters/answer/183669
if [ -f "${webroot}/robots.txt" ]; then
SITEMAPCHECK=$(grep 'Sitemap:' ${webroot}/robots.txt)
    if [ -z "$SITEMAPCHECK" ]; then
    echo "Sitemap: http://${url}/sitemap.xml" >> ${webroot}/robots.txt
    fi
fi
##############################################
echo "" > $path

# grab list of site urls
list=`wget -r --delete-after $url --reject=${reject} 2>&1 |grep "\-\-"  |grep http | grep -v 'normalize\.css' | awk '{ print $3 }'`

if [[ "$debug" = [yY] ]]; then
    echo "------------------------------------------------------"
    echo "Following list of urls will be submitted to Google"
    echo $list
    echo "------------------------------------------------------"
fi

# put list into an array
array=($list)

echo "------------------------------------------------------"
echo ${#array[@]} "pages detected for $url" 
echo "------------------------------------------------------"

# formatted properly according to
# https://support.google.com/webmasters/answer/35738
echo "<?xml version=\"1.0\" encoding=\"UTF-8\"?>
<urlset xsi:schemaLocation=\"http://www.sitemaps.org/schemas/sitemap/0.9 
http://www.sitemaps.org/schemas/sitemap/0.9/sitemap.xsd\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\"
xmlns=\"http://www.sitemaps.org/schemas/sitemap/0.9\">" > $path

echo ' 
   ' >> $path;
   for ((i=0;i<${#array[*]};i++)); do
echo "<url>
    <loc>${array[$i]:0}</loc>
    <lastmod>$date</lastmod>
    <changefreq>$freq</changefreq>
    <priority>$prio</priority>
</url>" >> $path
   done
echo "" >> $path
echo "</urlset>" >> $path

# notify Google
# URL encode urls as per https://support.google.com/webmasters/answer/183669
if [[ "$debug" = [nN] ]]; then
    wget  -q --delete-after http://www.google.com/webmasters/tools/ping?sitemap=http%3A%2F%2F${url}%2Fsitemap.xml

    rm -rf ${url}
else
    echo "wget  -q --delete-after http://www.google.com/webmasters/tools/ping?sitemap=http%3A%2F%2F${url}%2Fsitemap.xml"

    echo "rm -rf ${url}"
fi
echo "------------------------------------------------------"

exit 0

Execute o script como:

bash script.sh

ou apenas:

./script.sh

Quando bashé executado usando o nome sh, desativa a maioria de suas extensões, como o [[operador de teste.

Como você possui a #!/bin/bashlinha shebang, não precisa especificar explicitamente o interpretador de shell na linha de comando. A execução do script como um comando usará essa linha para encontrar o shell.

Ambos os seus ... if [[ debug = "...“ ]] ; then...comandos estão incorretos, eles devem ler ...

if [ "debug" = "Y" -o "debug" = "y" ]