使用shell脚本从文件中读取值

Question

我有一个Jenkinsfile，我想从一个shell脚本中读取一些值。

文件的部分是

-- Jenkinsfile
stage ('Setup Vars') {
  switch(BRANCH_NAME) {
    case 'develop':
      env.ECHO_CHAMBER_BRANCH = 'develop'
      env.HENDRICKS_JS_INTEGRATION_BRANCH = 'master'
      env.FEATURES_BRANCH = 'master'
    break
    case 'master':
      env.ECHO_CHAMBER_BRANCH = 'develop'
      env.HENDRICKS_JS_INTEGRATION_BRANCH = 'master'
      env.FEATURES_BRANCH = 'master'
    break
    default:
      env.ECHO_CHAMBER_BRANCH = 'feature-branch'
      env.HENDRICKS_JS_INTEGRATION_BRANCH = 'feature-branch'
      env.FEATURES_BRANCH = 'feature-branch'
    break
  }
}

我需要在case语句的默认部分中读取分配给env.ECHO_CHAMBER_BRANCH、env.HENDRICKS_JS_INTEGRATION和env.FEATURES_BRANCH的值，因此在这个示例中，我希望为每个变量返回feature-branch。

使用shell脚本，如何获得这些值？

Answer 1

改进的case_to_var脚本(使用"case_to_var文件名“)：

#!/bin/sed -nf
# Only look at lines ending in ':'
/:$/{
    # remove leading `case`, spaces, and the ':', and save name.
    s/.* \|://g
    h
    # until the `break` line, recall name, append variable name, 
    # and make it shell-parsable.
    :foo g
        N
        y/./_/
        s/'//g
        s/ = /=/
        s/\n.*env//gp
        /break$/!b foo
}

case_to_var Jenkinsfile输出

develop_ECHO_CHAMBER_BRANCH=develop
develop_HENDRICKS_JS_INTEGRATION_BRANCH=master
develop_FEATURES_BRANCH=master
master_ECHO_CHAMBER_BRANCH=develop
master_HENDRICKS_JS_INTEGRATION_BRANCH=master
master_FEATURES_BRANCH=master
default_ECHO_CHAMBER_BRANCH=feature-branch
default_HENDRICKS_JS_INTEGRATION_BRANCH=feature-branch
default_FEATURES_BRANCH=feature-branch

使输出shell可解析，允许执行和使用它；与谨慎使用eval一样

eval $(case_to_var Jenkinsfile)
echo $default_FEATURES_BRANCH $develop_FEATURES_BRANCH

输出：

feature-branch master

一条龙版本：

sed -n '/:$/{s/.* \|://g;h;:foo g;N;y/./_/;s/'"'"'//g;s/ = /=/;s/\n.*env//gp;/break$/!b foo}' Jenkinsfile