如何在 Linux BASH 中获取命令输出的一部分？
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How do I get a part of the output of a command in Linux BASH?
提问by William Edwards
As the title says, how do I get a part of the output of a command in Bash?
正如标题所说，如何在 Bash 中获取命令输出的一部分？
For example, the command php -voutputs:
例如，命令php -v输出：
PHP 5.3.28 (cli) (built: Jun 23 2014 16:25:09)
Copyright (c) 1997-2013 The PHP Group
Zend Engine v2.3.0, Copyright (c) 1998-2013 Zend Technologies with the ionCube PHP Loader v4.6.1, Copyright (c) 2002-2014, by ionCube Ltd.
and I only want to output the PHP 5.3.28 (cli)part, how do I do that?
我只想输出PHP 5.3.28 (cli)部分，我该怎么做？
I've tried php -v | grep 'PHP 5.3.28'but that outputs: PHP 5.3.28 (cli) (built: Jun 23 2014 16:25:09)and that's not what I want.
我试过，php -v | grep 'PHP 5.3.28'但输出：PHP 5.3.28 (cli) (built: Jun 23 2014 16:25:09)这不是我想要的。
回答by Avinash Raj
You could try the below awk command,
你可以试试下面的 awk 命令，
$ php -v | awk 'NR==1{print ,,}'
PHP 5.3.28 (cli)
It prints the first three columns from the first line of input.
它从输入的第一行打印前三列。
NR==1(condition)ie, execute the statements within{}only if the value of NR variable is 1.{print $1,$2,$3}Print col1,col2,col3.,in the print statement means OFS(Output Field Seperator)
NR==1（条件）即，{}仅当 NR 变量的值为 1 时才执行其中的语句。{print $1,$2,$3}打印 col1,col2,col3。,在打印语句中表示 OFS（输出字段分隔符）
回答by slavik
In pure bash you can do
在纯粹的 bash 中你可以做
echo 'PHP 5.3.28 (cli) (built: Jun 23 2014 16:25:09)' | cut -d '(' -f 1,2
Out:
出去：
PHP 5.3.28 (cli)
Or using space as delimiter
或者使用空格作为分隔符
echo 'PHP 5.3.28 (cli) (built: Jun 23 2014 16:25:09)' | cut -d ' ' -f 1,2,3
回答by nafas
if you want all the lines that contain "php" do this:
如果您想要包含“php”的所有行，请执行以下操作：
$ php -v | grep -i "php"
then supposedly you want the first three words within those you can add another pipe as @Avinash suggested:
那么据说您想要其中的前三个词，您可以按照@Avinash 的建议添加另一个管道：
$ php -v | grep -i "php" | awk 'NR==1{print ,,}'
回答by starkers
a classic "million ways to skin a cat" question..
一个经典的“给猫剥皮的百万种方法”问题。
These methods seem to filter by spaces.. if the versions/notes contains spaces this fails.
这些方法似乎按空格过滤……如果版本/注释包含空格，则失败。
The (brackets however seem consistent across all my platforms so I've used the following:
(然而，括号在我的所有平台上似乎都是一致的，所以我使用了以下内容：
EG: on debian:
EG：在 debian 上：
root@host:~# php -v | head -1
PHP 5.3.28-1~dotdeb.0 with Suhosin-Patch (cli) (built: Dec 13 2013 01:38:56)
root@host:~# php -v | head -1 | cut -d " " -f 1-2
PHP 5.3.28-1~dotdeb.0
So here I trim everything before the second (:
所以在这里我在第二个之前修剪所有东西(：
root@host:~# php -v | head -1 | cut -d "(" -f 1-2
PHP 5.3.28-1~dotdeb.0 with Suhosin-Patch (cli)
note: there will be a trailing white-space. (blank space at the end)
注意：会有一个尾随空格。（末尾有空格）
Alternatively you could always use your package manager to determine this (recommended):
或者，您可以始终使用您的包管理器来确定这一点（推荐）：
root@debian-or-ubuntu-host:~# dpkg -s php5 | grep 'Version'
Version: 5.3.28-1~dotdeb.0
....or on a centos/redhat/scientic linux distro:
....或在 centos/redhat/scientic linux 发行版上：
[root@rpm-based-host ~]# rpm -qa | grep php-5
php-5.4.28-1.el6.remi.x86_64
