英文:
How to save a specified line of a file to a variable
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
英文:
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 $varible
c
答案1
得分: 2
使用awk尝试：
VARIABLE=`awk 'NR==3' file`
或者使用sed：
VARIABLE=`sed '3!d' file`
英文:
Try using awk:
VARIABLE=`awk 'NR==3' file`
Or with sed
VARIABLE=`sed '3!d' file`
答案2
得分: 1
或者使用 `cut`：
```sh
VARIABLE="$(<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="$(<file cut -d $'\n' -f 3)"
Or using Bash specific read and the fastest for small line numbers
IFS=$'\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
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