关于grep过滤配置文件中的#注释

网上很多关于grep过滤#注释的方法都是 grep -v '^#'。

使用后发现这种方法有缺陷，就是有些注释并不是以#开头的，而是带有空格然后再是#。

于是就自己研究了下“正确”的过滤空行+注释的方法。

grep -Ev '^$|^\s*#'

^$ 匹配空行。

^\s*# 与原来的^#相比，增加了使用 \s* 来匹配 # 前面可能会出现的空格。

注： 注释#在正文后方的代码行不会有影响。

例如nginx.conf的原配置文件

[root@master-1:/usr/local]# cat /etc/nginx/nginx.conf
user www-data;
worker_processes auto;
pid /run/nginx.pid;
include /etc/nginx/modules-enabled/*.conf;

events {
    
    
    worker_connections 768;
    # multi_accept on;
}

http {
    
    

    ##
    # Basic Settings
    ##

    sendfile on;
    tcp_nopush on;
    tcp_nodelay on;
    keepalive_timeout 65;
    types_hash_max_size 2048;
    # server_tokens off;

    # server_names_hash_bucket_size 64;
    # server_name_in_redirect off;

    include /etc/nginx/mime.types;
    default_type application/octet-stream;

    ##
    # SSL Settings
    ##

    ssl_protocols TLSv1 TLSv1.1 TLSv1.2 TLSv1.3; # Dropping SSLv3, ref: POODLE
    ssl_prefer_server_ciphers on;

    ##
    # Logging Settings
    ##

    access_log /var/log/nginx/access.log;
    error_log /var/log/nginx/error.log;

    ##
    # Gzip Settings
    ##

    gzip on;

    # gzip_vary on;
    # gzip_proxied any;
    # gzip_comp_level 6;
    # gzip_buffers 16 8k;
    # gzip_http_version 1.1;
    # gzip_types text/plain text/css application/json application/javascript text/xml application/xml application/xml+rss text/javascript;

    ##
    # Virtual Host Configs
    ##

    include /etc/nginx/conf.d/*.conf;
    include /etc/nginx/sites-enabled/*;
}


#mail {
    
    
#    # See sample authentication script at:
#    # http://wiki.nginx.org/ImapAuthenticateWithApachePhpScript
#
#    # auth_http localhost/auth.php;
#    # pop3_capabilities "TOP" "USER";
#    # imap_capabilities "IMAP4rev1" "UIDPLUS";
#
#    server {
    
    
#        listen     localhost:110;
#        protocol   pop3;
#        proxy      on;
#    }
#
#    server {
    
    
#        listen     localhost:143;
#        protocol   imap;
#        proxy      on;
#    }
#}

使用 grep -Ev '^$|^#' 的结果还会带有部分注释。

[root@master-1:/usr/local]# grep -Ev '^$|^#' /etc/nginx/nginx.conf
user www-data;
worker_processes auto;
pid /run/nginx.pid;
include /etc/nginx/modules-enabled/*.conf;
events {
    
    
	worker_connections 768;
	# multi_accept on;
}
http {
    
    
	##
	# Basic Settings
	##
	sendfile on;
	tcp_nopush on;
	tcp_nodelay on;
	keepalive_timeout 65;
	types_hash_max_size 2048;
	# server_tokens off;
	# server_names_hash_bucket_size 64;
	# server_name_in_redirect off;
	include /etc/nginx/mime.types;
	default_type application/octet-stream;
	##
	# SSL Settings
	##
	ssl_protocols TLSv1 TLSv1.1 TLSv1.2 TLSv1.3; # Dropping SSLv3, ref: POODLE
	ssl_prefer_server_ciphers on;
	##
	# Logging Settings
	##
	access_log /var/log/nginx/access.log;
	error_log /var/log/nginx/error.log;
	##
	# Gzip Settings
	##
	gzip on;
	# gzip_vary on;
	# gzip_proxied any;
	# gzip_comp_level 6;
	# gzip_buffers 16 8k;
	# gzip_http_version 1.1;
	# gzip_types text/plain text/css application/json application/javascript text/xml application/xml application/xml+rss text/javascript;
	##
	# Virtual Host Configs
	##
	include /etc/nginx/conf.d/*.conf;
	include /etc/nginx/sites-enabled/*;
}

使用 grep -Ev '^$|^\s*#' 就可以正常的去掉全部注释。

[root@master-1:/usr/local]# grep -Ev '^$|^\s*#' /etc/nginx/nginx.conf
user www-data;
worker_processes auto;
pid /run/nginx.pid;
include /etc/nginx/modules-enabled/*.conf;
events {
    
    
	worker_connections 768;
}
http {
    
    
	sendfile on;
	tcp_nopush on;
	tcp_nodelay on;
	keepalive_timeout 65;
	types_hash_max_size 2048;
	include /etc/nginx/mime.types;
	default_type application/octet-stream;
	ssl_protocols TLSv1 TLSv1.1 TLSv1.2 TLSv1.3; # Dropping SSLv3, ref: POODLE
	ssl_prefer_server_ciphers on;
	access_log /var/log/nginx/access.log;
	error_log /var/log/nginx/error.log;
	gzip on;
	include /etc/nginx/conf.d/*.conf;
	include /etc/nginx/sites-enabled/*;
}