问题

I want to save a specified line of a file to a variable in bash script
example:

FileToReadFromThat.txt

a
b
c
d
e

What I want to save in a simple line:

variable="line 3 from $HOME/FileToReadFromThat.txt"

And result to get from that:

$ echo $varible
c

a
b
c
d
e

variable="line 3 from $HOME/FileToReadFromThat.txt"

$ echo $varible
c

答案1

得分: 2

使用awk尝试：

VARIABLE=`awk 'NR==3' file`

或者使用sed：

VARIABLE=`sed '3!d' file`

VARIABLE=`awk 'NR==3' file`

VARIABLE=`sed '3!d' file`

答案2

得分: 1

或者使用 `cut`：
```sh
VARIABLE="$(<file cut -d $'\n' -f 3)"

或者使用Bash特定的read，对于小行数来说速度最快的方式：

IFS=$'\n' read -r -d '' _ _ VARIABLE _ <file

或者使用Bash的mapfile，可能是最多功能且最快的方式，只使用Bash的内置命令而不派生子进程：

mapfile -t -s 2 -n 1 VARIABLE <file

<details>
<summary>英文:</summary>
Or `cut`:
```sh
VARIABLE=&quot;$(&lt;file cut -d $&#39;\n&#39; -f 3)&quot;

Or using Bash specific read and the fastest for small line numbers

IFS=$'\n' read -r -d '' _ _ VARIABLE _ <file

or using Bash's mapfile and probably the most versatile and fastest way using only Bash's built-in commands without forking sub-processes:

mapfile -t -s 2 -n 1 VARIABLE <file