如果使用变量，可以使用

first_var="Hello"
second_var="How are you"

如果你想连接两个字符串并将其写入文件，那么使用下面的方法

echo "${first_var} - ${second_var}" > ./file_name.txt

你的file_name.txt内容将是"Hello - How are you"

我喜欢这个答案:

cat > FILE.txt <<EOF

info code info 
...
EOF

但建议cat >> file .txt << EOF，如果你只是想在文件末尾添加一些东西，而不清除已经存在的东西

是这样的:

cat >> FILE.txt <<EOF

info code info 
...
EOF

我知道这是一个该死的老问题，但由于OP是关于脚本的，而且谷歌将我带到了这里，因此还应该提到同时打开文件描述符以进行读写。

#!/bin/bash

# Open file descriptor (fd) 3 for read/write on a text file.
exec 3<> poem.txt

    # Let's print some text to fd 3
    echo "Roses are red" >&3
    echo "Violets are blue" >&3
    echo "Poems are cute" >&3
    echo "And so are you" >&3

# Close fd 3
exec 3>&-

然后在终端上cat文件

$ cat poem.txt
Roses are red
Violets are blue
Poems are cute
And so are you

This example causes file poem.txt to be open for reading and writing on file descriptor 3. It also shows that *nix boxes know more fd's then just stdin, stdout and stderr (fd 0,1,2). It actually holds a lot. Usually the max number of file descriptors the kernel can allocate can be found in /proc/sys/file-max or /proc/sys/fs/file-max but using any fd above 9 is dangerous as it could conflict with fd's used by the shell internally. So don't bother and only use fd's 0-9. If you need more the 9 file descriptors in a bash script you should use a different language anyways :)

无论如何，fd可以以许多有趣的方式使用。

#!/bin/bash

cat > FILE.txt <<EOF

info code info 
info code info
info code info

EOF 

如果使用变量，可以使用

first_var="Hello"
second_var="How are you"

如果你想连接两个字符串并将其写入文件，那么使用下面的方法

echo "${first_var} - ${second_var}" > ./file_name.txt

你的file_name.txt内容将是"Hello - How are you"

#!/bin/sh

FILE="/path/to/file"

/bin/cat <<EOM >$FILE
text1
text2 # This comment will be inside of the file.
The keyword EOM can be any text, but it must start the line and be alone.
 EOM # This will be also inside of the file, see the space in front of EOM.
EOM # No comments and spaces around here, or it will not work.
text4 
EOM