grep 同时知足多个关键字和知足任意关键字

grep 同时知足多个关键字和知足任意关键字

① grep -E "word1|word2|word3"   file.txt

   知足任意条件（word一、word2和word3之一）将匹配。

② grep word1 file.txt | grep word2 |grep word3

   必须同时知足三个条件（word一、word2和word3）才匹配。

 

 

其实这很好理解，只是我平时没有用多个关键字搜索过，一会儿有点蒙，平时遇到也是先度娘，哈哈哈哈哈，哎

 

grep keyword filename  |  grep keyword2

前一段多搜索结果  经过管道到另外一边 在查询颇有关键字keyword2到

 

却是知足任何一个关键字到， -E命令要记一下

 

 

 

-E, --extended-regexp

             Interpret pattern as an extended regular expression (i.e. force

             grep to behave as egrep).

 

     -e pattern, --regexp=pattern

             Specify a pattern used during the search of the input: an input

             line is selected if it matches any of the specified patterns.

             This option is most useful when multiple -e options are used to

             specify multiple patterns, or when a pattern begins with a dash

             (`-').

 

     --exclude

             If specified, it excludes files matching the given filename pat-

             tern from the search.  Note that --exclude patterns take priority

             over --include patterns, and if no --include pattern is speci-

             fied, all files are searched that are not excluded.  Patterns are

             matched to the full path specified, not only to the filename com-

             ponent.

 

     --exclude-dir

             If -R is specified, it excludes directories matching the given

             filename pattern from the search.  Note that --exclude-dir pat-

             terns take priority over --include-dir patterns, and if no

             --include-dir pattern is specified, all directories are searched

             that are not excluded.

 

     -F, --fixed-strings

             Interpret pattern as a set of fixed strings (i.e. force grep to

             behave as fgrep).

 

     -f file, --file=file

             Read one or more newline separated patterns from file.  Empty

             pattern lines match every input line.  Newlines are not consid-

             ered part of a pattern.  If file is empty, nothing is matched.