巴什反引号逃逸 [英] Bash backtick escaping

问题描述

这是Bash的变量声明语句：

 富='b'``'AR​​'
 

少的有效的莫过于：

 富='吧'
 

是否格式化挂或对齐缩进（线延续）这种方式：

  a_long_variable_name ='一个看似无限长的'`
                    `'字串需要continuatio'`
                    `'N下一行......
 

产卵子壳，浪费资源，或影响性能以任何方式，除了
讨厌那些谁不喜欢它的形式（抗？）可读性？

效率为：的电脑的效率，而不是人类打字许多人物和创建基于空间的，无偿维修债

会影响（或缺乏）业绩很容易地证明？

解决方案

  tester1（）{
  因为我在{1..1000};做
    a_long_variable_name ='一个看似无限长的'`
                        `'字串需要continuation'`
                        `'下一行......
    回声$ a_long_variable_name＆GT; TMP
  DONE
}tester2（）{
  因为我在{1..1000};做
    a_long_variable_name =一个看似无限长\\
字符串需要延续\\
在下一行......
    回声$ a_long_variable_name＆GT; TMP
  DONE
}回声tester1
时间tester1
回声tester2
时间tester2
 

结果

  tester1真正0m1.878s
用户0m0.209s
SYS 0m0.566stester2真正0m0.335s
用户0m0.026s
SYS 0m0.078s
 

这些都具有相似的时序，以案例2：

 读-r -d''a_long_variable_name＆LT;＆LT; EOF
    一个看似无限长
    字符串需要延续
    在下一行...
EOFa_long_variable_name =一个看似无限长\\
                      字符串需要延续\\
                      在下一行......
 

Is this Bash variable declaration statement:

foo='b'`    `'ar'

less efficient than this:

foo='bar'

Does this way of formatting "hanging" or "aligned" indents (line continuations):

a_long_variable_name='a seemingly infinitely long '`
                    `'string requiring continuatio'`
                    `'n on the next line...'

spawn sub-shells, waste resources, or affect performance in any way, apart from annoying those who dislike its form for (anti?)readability?

Efficiency as in: computer efficiency, not "humans typing many characters and creating space-based, gratuitous maintenance debt".

Can impact (or lack thereof) on performance be easily demonstrated?

解决方案

tester1() {
  for i in {1..1000}; do
    a_long_variable_name='a seemingly infinitely long '`
                        `'string requiring continuation'`
                        `'on the next line...'
    echo $a_long_variable_name > tmp 
  done
}

tester2() {
  for i in {1..1000}; do
    a_long_variable_name="a seemingly infinitely long\
string requiring continuation\
on the next line..."
    echo $a_long_variable_name > tmp 
  done
}

echo tester1
time tester1
echo tester2
time tester2

Results

tester1

real    0m1.878s
user    0m0.209s
sys     0m0.566s

tester2

real    0m0.335s
user    0m0.026s
sys     0m0.078s

These all have similar timings to case 2:

read -r -d '' a_long_variable_name <<EOF
    a seemingly infinitely long
    string requiring continuation
    on the next line...
EOF

a_long_variable_name="a seemingly infinitely long\
                      string requiring continuation\
                      on the next line..."

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