[ruby] Add, delete, and modify file content

Prerequisite: mac environment (other environments are slightly different)

1. Delete a row

# 删除前两行
# sed -i '' '1,2d' 文件名
sed -i '' '1,2d' Podfile

2. Add characters before each line of text

#sed 's/^/添加的字符串&/g' 文件名
sed 's/^/添加的字符串&/g' Podfile

3. Replace string

sed -i '' 's/newstr/oldstr/g' Podfile

4. Insert in a row

# 在第一行插入某字符串
sed -i '' "1a\\
if ARGV[2] != '--ln-s' \\
" Podfile

5. Create a new file and insert multiple lines of text

echo '创建计时脚本:pod_time.rb'
touch pod_time.rb
echo '
def pod_time
    startTime = Time.now.to_i
    target_name = "Test"
    post_install do |installer|
        installer.pods_project.targets.each do |target|
            target_name = target.name
        end 
        endTime = Time.now.to_i
        compileTime = endTime - startTime
        compileType = "3"
    end
end
'> pod_time.rb