Grep command usage

n When matching rows are displayed , Display with file line number .（ Display the line number of the result ）

R Recursively read all files in each directory , Follow all matching links .

i Ignore character case differences

-E Can deliver multiple content , Use | To split multiple pattern , To achieve OR operation

[[email protected] ~]# grep -Rn "LoadModule" /etc/httpd*

/etc/httpd/conf/httpd.conf:48:# have to place corresponding `LoadModule' lines at this location so the
/etc/httpd/conf/httpd.conf:54:# LoadModule foo_module modules/mod_foo.so
/etc/httpd/conf.modules.d/00-dav.conf:1:LoadModule dav_module modules/mod_dav.so
/etc/httpd/conf.modules.d/00-dav.conf:2:LoadModule dav_fs_module modules/mod_dav_fs.so
/etc/httpd/conf.modules.d/00-dav.conf:3:LoadModule dav_lock_module modules/mod_dav_lock.so
/etc/httpd/conf.modules.d/00-lua.conf:1:LoadModule lua_module modules/mod_lua.so