linux命令积累之egrep命令

学搭建Nginx环境，必须要配置的Nginx.conf文件中，如下：

#user nobody;
worker_processes 1;

#error_log logs/error.log;
#error_log logs/error.log notice;
#error_log logs/error.log info;

#pid logs/nginx.pid;

events {
worker_connections 1024;
}

http {
include mime.types;
default_type application/octet-stream;

    #log_format main '$remote_addr - $remote_user [$time_local] "$request" '
    #                  '$status $body_bytes_sent "$http_referer" '
    #                  '"$http_user_agent" "$http_x_forwarded_for"';

#access_log logs/access.log main;

sendfile on;
#tcp_nopush on;

#keepalive_timeout 0;
keepalive_timeout 65;

#gzip on;

    server {
        listen       80;
        server_name localhost;

#charset koi8-r;

#access_log logs/host.access.log main;

        location / {
            root   html;
            index index.html index.htm;
        }

一般我们初学的，不可能一下子把配置文件一下子搭出来。要逐个模块去了解，注释部分可以先去掉，接下来就可以用这个命令进行排除掉#和空行

语法

grep -v '#|^$' filename

egrep -v '#|^$' filename

命令的作用

grep, egrep, fgrep - print lines matching a pattern

参数：

-v, --invert-match 排除

-E, --extended-regexp

egrep -i 'devops' file 不考虑sam的大小写,含有sam的行.
egrep -l "dear ken" * 包含dear ken的所有文件的清单.
egrep -n tom file 包含tom的行, 每行前面追加行号.
egrep -s "$name" file 找到变量名$name的, 不打印而是显示退出状态. 0表示找到. 1表示表达式没找到符合要求的, 2表示文件没找到.

实例：

[root@web01 conf]# egrep -v '#|^$' nginx.conf.default > nginx.conf
[root@web01 conf]# cat nginx.conf
worker_processes 1;
events {
    worker_connections 1024;
}
http {
    include       mime.types;
    default_type application/octet-stream;
    sendfile        on;
    keepalive_timeout 65;
    server {
        listen       80;
        server_name localhost;
        location / {
            root   html;
            index index.html index.htm;
        }
        error_page   500 502 503 504 /50x.html;
        location = /50x.html {
            root   html;
        }
    }
}