echo $ with Bash

Question

我为某些东西编写了一个安装脚本，现在我需要用它创建一个虚拟主机。为此，我使用了以下代码：

echo -e \
"WSGISocketPrefix $DIRECTORY/socks/\n"\
"WSGIPythonHome $DIRECTORY/env/local\n"\
"WSGIRestrictStdout On\n"\
"WSGIRestrictSignal Off\n"\
"WSGIPythonOptimize 1\n"\
"<VirtualHost *:80>\n"\
"   ServerAdmin root@localhost.com\n"\
"   ServerName app.localhost\n"\
"   DocumentRoot \"$DIRECTORY\"\n"\
"   Alias /m/ $DIRECTORY/static/\n"\
"   Alias /upfiles/ $DIRECTORY/askbot/upfiles/\n"\
"   <DirectoryMatch \"$DIRECTORY/askbot/skins/([^/]+)/media\">\n"\
"       Order deny,allow\n"\
"       Allow from all\n"\
"   </DirectoryMatch>\n"\
"   <Directory \"$DIRECTORY/askbot/upfiles\">\n"\
"       Order deny,allow\n"\
"       Allow from all\n"\
"   </Directory>\n"\
"\n"\
"   WSGIDaemonProcess askbot_"$NUMBER"_\n"\
"   WSGIProcessGroup askbot_"$NUMBER"_\n"\
"   WSGIScriptAlias / $DIRECTORY/django.wsgi\n"\
"\n"\      
'   ErrorLog ${APACHE_LOG_DIR}/askbot_error.log'"\n"\
'   CustomLog ${APACHE_LOG_DIR}/askbot_access.log combined'"\n"\
"</VirtualHost>\n" > /etc/apache2/sites-available/app.conf

$DIRECTORY是一个包含路径的变量，因此应该打印它的内容。然而，${APACHE_LOG_DIR}在这里并不是变量，应该按原样打印。不幸的是，它不是将内容写入文件，而是将内容回显到终端，出现一些错误(文件未找到等)。当我删除最后两行时，它确实有效，但这当然不是一个解决方案，但我似乎无法让它工作。

有什么想法吗？

Answer 1

用这里的文件。如果需要的话，可以使用\来避开美元符号。

cat <<EOF > /etc/apache2/sites-available/app.conf
WSGISocketPrefix $DIRECTORY/socks/
WSGIPythonHome $DIRECTORY/env/local
WSGIRestrictStdout On
WSGIRestrictSignal Off
WSGIPythonOptimize 1
<VirtualHost *:80>
   ServerAdmin root@localhost.com
   ServerName app.localhost
   DocumentRoot "$DIRECTORY"
   Alias /m/ $DIRECTORY/static/
   Alias /upfiles/ $DIRECTORY/askbot/upfiles/
   <DirectoryMatch "$DIRECTORY/askbot/skins/([^/]+)/media">
       Order deny,allow
       Allow from all
   </DirectoryMatch>
   <Directory "$DIRECTORY/askbot/upfiles">
       Order deny,allow
       Allow from all
   </Directory>

   WSGIDaemonProcess askbot_$NUMBER_
   WSGIProcessGroup askbot_$NUMBER_
   WSGIScriptAlias / $DIRECTORY/django.wsgi

   ErrorLog \${APACHE_LOG_DIR}/askbot_error.log
   CustomLog \${APACHE_LOG_DIR}/askbot_access.log combined
</VirtualHost>
EOF

Answer 2

echo理解多行字符串：

echo "
fist section here with ${substitutions}


" > /etc/apache2/sites-available/app.conf

然后追加最后一节：

echo '
second section here without substitutions
' >> /etc/apache2/sites-available/app.conf

但是在这种情况下，创建一个模板文件然后使用例如sed来进行字符串替换可能更容易吗？我使用Jinja2的命令行接口来执行相同的任务(https://github.com/kolypto/j2cli)，但对于这样一个简单的模板，这几乎肯定是过分的；)