如何使用BASH编写多行配置文件,并在多行上使用变量？

Question

如何在myconfig.conf使用BASH 调用的文件中编写多行？

#!/bin/bash
kernel="2.6.39";
distro="xyz";

echo <<< EOL
line 1, ${kernel}
line 2,
line 3, ${distro}
line 4
line ...
EOL >> /etc/myconfig.conf;
cat /etc/myconfig.conf;

Answer 1

语法(<<<)和使用的命令(echo)是错误的.

正确的是:

#!/bin/bash

kernel="2.6.39"
distro="xyz"
cat >/etc/myconfig.conf <<EOL
line 1, ${kernel}
line 2, 
line 3, ${distro}
line 4 line
... 
EOL

cat /etc/myconfig.conf

Answer 2

#!/bin/bash
kernel="2.6.39";
distro="xyz";

cat > /etc/myconfig.conf << EOL
line 1, ${kernel}
line 2,
line 3, ${distro}
line 4
line ...
EOL

这样做你想要的.

Answer 3

如果您不想更换变量,则需要用单引号括起EOL.

cat >/tmp/myconfig.conf <<'EOL'
line 1, ${kernel}
line 2, 
line 3, ${distro}
line 4 line
... 
EOL

上一个例子:

$ cat /tmp/myconfig.conf 
line 1, ${kernel}
line 2, 
line 3, ${distro}
line 4 line
... 

Answer 4

heredoc解决方案当然是最常用的方法.其他常见解决方案是:

echo 'line 1, '"${kernel}"'
line 2,
line 3, '"${distro}"'
line 4' > /etc/myconfig.conf

和

exec 3>&1 # Save current stdout
exec > /etc/myconfig.conf
echo line 1, ${kernel}
echo line 2, 
echo line 3, ${distro}
...
exec 1>&3  # Restore stdout

Answer 5

我正在使用Mac OS并在SH 脚本中编写多行，以下代码对我有用

#! /bin/bash
FILE_NAME="SomeRandomFile"

touch $FILE_NAME

echo """I wrote all
the  
stuff
here.
And to access a variable we can use
$FILE_NAME  

""" >> $FILE_NAME

cat $FILE_NAME

请不要忘记根据需要为脚本文件分配 chmod。我用过

chmod u+x myScriptFile.sh