shell使用技巧

shell_tips.sh

# 遍历一个数字范围， https://stackoverflow.com/questions/169511/how-do-i-iterate-over-a-range-of-numbers-defined-by-variables-in-bash
for i in $(seq 1 $END); do echo $i; done

# 枚举多台机器上的java堆栈
for i in $(seq 204 231); do ssh 192.168.12.$i "ls -lh /opt/log/stash/customer/java_pid1.hprof"; done

# 使用sed做替换
gsed -i -e 's/\(FROM .*alpine-openjdk8[^:]*\)$/\1:8u221/g' */*/Dockerfile

# 使用ruby处理json行, 并设定encoding
ruby -n -r json -e "BEGIN {ARGF.set_encoding('gb2312')}" -e 'j=JSON.parse($_); puts "#{j["identityCustomerId"]}, #{j["attr"]["attr3"]}"' registerStore_attr3.csv