[英]Replace bash variables in template file
我正在尝试使用 Bash 来运行某种形式的安装过程。 在此过程中,会复制配置文件并替换其中的某些值。 这样的配置可以在下面找到:
server {
listen 80;
root ${INSTALLPATH};
server_name ${SITEURL};
client_max_body_size 20m;
client_body_timeout 120s;
location / {
try_files /public/router.php =404;
fastcgi_split_path_info ^(.+?\.php)(/.*)$;
fastcgi_pass ${PHPSERV};
fastcgi_index router.php;
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
include /etc/nginx/fastcgi_params;
}
location /assets {
try_files /app/$uri =404;
}
}
#Enables HTTPS access
#This requires you to install certificates and is not enabled by default
#If you wish to enable HTTPS, uncomment (remove the #s) from the below lines
#And change the ssl_certificate and ssl_certificate_key to point to the correct
#certificates.
#server {
# listen 443;
# root ${INSTALLPATH};
# server_name ${SITEURL};
#
# ssl on;
# ssl_certificate /etc/nginx/ssl/site.crt;
# ssl_certificate_key /etc/nginx/ssl/site.key;
#
# location / {
# try_files /public/router.php =404;
# fastcgi_split_path_info ^(.+?\.php)(/.*)$;
# fastcgi_pass ${PHPSERV};
# fastcgi_index router.php;
# fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
# include /etc/nginx/fastcgi_params;
# }
#
# location /assets {
# try_files /app/$uri =404;
# }
#
#}
我发现大多数示例都源于 eval 的使用,并且我尝试使用它来进行此替换,但是似乎此处的文件没有正确扩展,并且 bash 尝试执行某些内容并且不能执行。
目前,我有这个
INSTALLPATH="/var/www/html/mycustomsite/"
PHPSERV="127.0.0.1:9000"
SITEURL="example.com"
while read -r line; do
eval echo -e "${line}"
done < template
但是,这不能正确替换声明的值,也不能正确生成文件。 例如,它会丢失任何以 # 开头的行并尝试执行其他行(同时丢失一些间距)。
仅使用 Bash 和大多数 Linux 系统上可用的命令来执行此操作的正确方法是什么?
这不考虑安全问题! 使用eval
是邪恶的!
兼容的答案不是更好!
当然,你必须对你的模板内容有信心!!
如果没有,请尝试使用sed ! (见我最后的回答)
在bash 下,您可以简单地:
eval "INSTALLPATH='/somepath/somewhere' SITEURL='example.com' PHPSERV='127.0.0.1:9000'; echo \"$(<template)\""
或者
eval "INSTALLPATH='/somepath/somewhere'
SITEURL='example.com'
PHPSERV='127.0.0.1:9000';
echo \"$(<template)\""
当您使用eval
,您可以将生成的配置文件存储到一个变量中:
eval "INSTALLPATH='/somepath/somewhere'
SITEURL='example.com'
PHPSERV='127.0.0.1:9000';
cfgBody=\"$(<template)\""
然后
echo "$cfgBody"
和/或
echo "$cfgBody" >/cfgpath/cfgfile
tmplBody="$(<template)"
while read INSTALLPATH SITEURL PHPSERV CFGFILE;do
[ "$CFGFILE" ] && eval "echo \"$tmplBody\"" >"$CFGFILE"
done <<<"
/somepath/somewhere example.com 127.0.0.1:9000 /tmp/file1
'/some\ other\ path/elsewhere' sample2.com 127.0.0.1:9001 /tmp/file2
"
注意:在第二行,有转义空格(前面带有反斜杠\\
和引号'
。反斜杠告诉read
不要拆分变量,并且引号必须添加到结果/tmp/file2
。
#!/bin/sh
(
cat <<eohead
#!/bin/sh
INSTALLPATH='/somepath/somewhere'
SITEURL='example.com'
PHPSERV='127.0.0.1:9000';
cat <<eof
eohead
cat template
echo eof
) | /bin/sh
这不需要 bash,在dash和busybox下进行了测试。
sedcmd=''
for var in INSTALLPATH SITEURL PHPSERV;do
printf -v sc 's/${%s}/%s/;' $var "${!var//\//\\/}"
sedcmd+="$sc"
done
sed -e "$sedcmd" <template
可以进入一个循环:
while read INSTALLPATH SITEURL PHPSERV CFGFILE;do
if [ "$CFGFILE" ] ;then
sedcmd=''
for var in INSTALLPATH SITEURL PHPSERV;do
printf -v sc 's/${%s}/%s/;' $var "${!var//\//\\/}"
sedcmd+="$sc"
done
sed -e "$sedcmd" <template >"$CFGFILE"
fi
done <<<"
/somepath/somewhere example.com 127.0.0.1:9000 /tmp/file1
'/some\ other\ path/elsewhere' sample2.com 127.0.0.1:9001 /tmp/file2
"
sed
这可以在没有所谓的bashisms 的情况下工作,进入循环:
#!/bin/sh
while read INSTALLPATH SITEURL PHPSERV CFGFILE;do
sedcmd="s|\\\${INSTALLPATH}|${INSTALLPATH}|;"
sedcmd="${sedcmd}s|\\\${SITEURL}|${SITEURL}|;"
sedcmd="${sedcmd}s|\\\${PHPSERV}|${PHPSERV}|;"
sed -e "$sedcmd" template >"$CFGFILE"
done <<eof
/somepath/somewhere example.com 127.0.0.1:9000 /tmp/file1
'/some\ other\ path/elsewhere' sample2.com 127.0.0.1:9001 /tmp/file2
eof
比较输出:
diff -u99 /tmp/file{1,2}
--- /tmp/file1 2015-05-31 11:02:03.407463963 +0200
+++ /tmp/file2 2015-05-31 11:02:03.407463963 +0200
@@ -1,22 +1,22 @@
server {
listen 80;
- root /somepath/somewhere;
- server_name example.com;
+ root '/some other path/elsewhere';
+ server_name sample2.com;
client_max_body_size 20m;
client_body_timeout 120s;
location / {
try_files /public/router.php =404;
fastcgi_split_path_info ^(.+?\.php)(/.*)$;
- fastcgi_pass 127.0.0.1:9000;
+ fastcgi_pass 127.0.0.1:9001;
fastcgi_index router.php;
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
include /etc/nginx/fastcgi_params;
}
location /assets {
try_files /app/$uri =404;
}
}
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