标签：循环 div 读取文件 name 默认 ice aaa alice 保存
awk ‘awk_program‘ a.txt
awk示例:
[root@docker-01 ~]# awk ‘{print $0}‘ a.txt # 输出a.txt中的每一行 ID name gender age email phone 1 Bob male 28 abc@qq.com 18023394012 2 Alice female 24 def@gmail.com 18084925203 3 Tony male 21 aaa@163.com 17048792503 4 Kevin male 21 bbb@189.com 17023929033 5 Alex male 18 ccc@xyz.com 18185904230 6 Andy female 22 ddd@139.com 18923902352 7 Jerry female 25 exdsa@189.com 18785234906 8 Peter male 20 bax@qq.com 17729348758 9 Steven female 23 bc@sohu.com 15947893212 10 Bruce female 27 bcbd@139.com 13942943905 [root@docker-01 ~]# awk ‘{print $0}{print "hello";print "world"}‘ a.txt ID name gender age email phone hello world 1 Bob male 28 abc@qq.com 18023394012 hello world 2 Alice female 24 def@gmail.com 18084925203 hello world 3 Tony male 21 aaa@163.com 17048792503 hello world 4 Kevin male 21 bbb@189.com 17023929033 hello world 5 Alex male 18 ccc@xyz.com 18185904230 hello world 6 Andy female 22 ddd@139.com 18923902352 hello world 7 Jerry female 25 exdsa@189.com 18785234906 hello world 8 Peter male 20 bax@qq.com 17729348758 hello world 9 Steven female 23 bc@sohu.com 15947893212 hello world 10 Bruce female 27 bcbd@139.com 13942943905 hello world # 多个代码块，代码块中多个语句 # 输出每行之后还输出两行：hello行和world行
对于awk ‘{print $0}‘ a.txt，它类似于shell的while循环while read line;do echo "$line";done <a.txt。awk隐藏了读取每一行的while循环，它会自动读取每一行，其中的{print $0}对应于Shell的while循环体echo "$line"部分。
下面再分析该awk命令的执行过程：
$0，于是$0中保存的就是本次所读取的行数据{print $0}并执行其中代码print $0，即输出$0，也即输出当前所读取的行$0print $0$0，再执行代码块
标签：循环 div 读取文件 name 默认 ice aaa alice 保存
原文地址：https://www.cnblogs.com/liujunjun/p/12388894.html
