shell编程系列20--文本处理三剑客之awk常用选项

shell编程系列20--文本处理三剑客之awk常用选项awk选项总结选项        解释
-v        参数传递
-f        指定脚本文件
-F        指定分隔符
-V        查看awk的版本号[root@localhost shell]# awk -v num2="$num1" -v var1="$var" 'BEGIN{print num2,var1}'
20 hello world# -f 选项 文件中读取表达式
[root@localhost shell]# cat 1.awk 
BEGIN{str="I hava a tream"location=index(str,"ea")print location
}
[root@localhost shell]# awk -f 1.awk 
12[root@localhost shell]# awk -f 2.awk 
Transaction $ Start,Event ID:9002
[root@localhost shell]# cat 2.awk 
BEGIN{str="Transaction 243 Start,Event ID:9002"count=sub(/[0-9]+/,"$",str)print str
}# -F 指定分隔符
[root@localhost shell]# awk -F ":" '{print $7}' passwd 
/bin/bash
/sbin/nologin
/sbin/nologin
/sbin/nologin
/sbin/nologin
/bin/sync
/sbin/shutdown
/sbin/halt
/sbin/nologin
/sbin/nologin
/sbin/nologin
/sbin/nologin
/sbin/nologin
/sbin/nologin
/sbin/nologin
/sbin/nologin
/sbin/nologin
/sbin/nologin
/bin/bash
/sbin/nologin
/bin/bash
/sbin/nologin# 显示版本号
[root@localhost shell]# awk -V
GNU Awk 4.0.2
Copyright (C) 1989, 1991-2012 Free Software Foundation.This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.You should have received a copy of the GNU General Public License
along with this program. If not, see http://www.gnu.org/licenses/.