用regex替换配置文件

Question

我有文件unbound.conf

如下所示

## Simple recursive caching DNS, UDP port 53
## unbound.conf -- https://calomel.org
#
server:
   access-control: 10.0.0.0/8 allow
   verbosity: 1

forward-zone:
      name: "."
      forward-addr: 8.8.4.4        # Google
      forward-addr: 8.8.8.8        # Google

forward-zone:
      name: "example.com"
      forward-addr: 50.116.23.211  # Open

some-other-config:
      key: "value"

我正在从变量(例如FORWARD_ZONES )中获取前向区域，其示例值为

forward-zone:
      name: "somedns.com"
      forward-addr: 1.1.1.1
      forward-addr: 2.2.2.2

forward-zone:
      name: "someotherdns.com"
      forward-addr: 3.3.3.3
      forward-addr: 4.4.4.4

我需要删除conf文件中的所有前向区域，并根据接收到的输入json数组创建新的区域。

因此，在应用regex结束时，我希望有以下基于上述输入的

## Simple recursive caching DNS, UDP port 53
## unbound.conf -- https://calomel.org
#
server:
   access-control: 10.0.0.0/8 allow
   verbosity: 1

forward-zone:
      name: "somedns.com"
      forward-addr: 1.1.1.1
      forward-addr: 2.2.2.2

forward-zone:
      name: "someotherdns.com"
      forward-addr: 3.3.3.3
      forward-addr: 4.4.4.4

some-other-config:
      key: "value"

我应该使用什么regex来达到上述目的？

sed -i "whatShouldBeRegexStringHereThatUses_FORWARD_ZONES_variable" unbound.conf

编辑:这是操场，它也展示了我做了什么，https://regex101.com/r/x0H2p3/1/

Answer 1

下面这句话对我有用

sed -zri 's/(forward-zone:\s*\n\s*name: \".*\"\s*\n\s*(forward-addr: [0-9\.]*.*\s*\n\s*)+\s*\n\s*)+/$FORWARD_ZONES/' unbound.conf

我需要得到一个有效的regex https://regex101.com/r/x0H2p3/2

然后用sed和

'-z'
'--null-data'
'--zero-terminated'
     Treat the input as a set of lines, each terminated by a zero byte
     (the ASCII 'NUL' character) instead of a newline.  This option can
     be used with commands like 'sort -z' and 'find -print0' to process
     arbitrary file names.

和

'-E'
'-r'
'--regexp-extended'
     Use extended regular expressions rather than basic regular
     expressions.  Extended regexps are those that 'egrep' accepts; they
     can be clearer because they usually have fewer backslashes.
     Historically this was a GNU extension, but the '-E' extension has
     since been added to the POSIX standard
     (http://austingroupbugs.net/view.php?id=528), so use '-E' for
     portability.  GNU sed has accepted '-E' as an undocumented option
     for years, and *BSD seds have accepted '-E' for years as well, but
     scripts that use '-E' might not port to other older systems.  *Note
     Extended regular expressions: ERE syntax.

Answer 2

我相信，awk可以通过以下方式实现这一点：

awk 'BEGIN{p=1}
     /^[-a-zA-Z]*:[[:blank:]]*$/{p=1}
     /^forward-zone:[[:blank:]]*$/{p=0}
     (p==0&&v==0){print var;print ""; v=1}
     p' var=$FORWARD_ZONES foo.conf

它本质上使用变量p检查是否需要打印一行。如果它找到一个带有regex ^[-a-zA-Z]*:[[:blank:]]*$的新配置块，那么它将默认设置打印标志p=1，但是如果配置块是^forward-zone:[[:blank:]]*$，它将禁用打印。第一次禁用打印时，它将注入$FORWARD_ZONES。

如果您的前向区域位于另一个名为forward_zones.conf的文件中，则可以使用

awk 'BEGIN{p=1}
     /^[-a-zA-Z]*:[[:blank:]]*$/{p=1}
     /^forward-zone:[[:blank:]]*$/{while(getline line<f2){print line); p=0}
     (p==0&&v==0){print ""; v=1}
     p' f2=forward_zones.conf foo.conf