Such as I have one file:
file1

hostname=abcd1234
server name=qwer1234

I need get the value of hostname: abcd1234 and the server name value to input file2, how to write a script do that? Thanks a lot!
file2.sh

#!/bin/sh
var1=$hostname
var2=$server name

echo $var1
echo $var2

Is the space in the variable name a requirement? Else you can just source file1 in file2.sh:

#!/bin/sh

. ./file1

var1=$hostname
var2=$server_name

echo $var1
echo $var2

Did you try source file1 before the var= parts from within file2.sh yet?

hth

Sorry, maybe I don't write clearly.
my means if the file1 not hostname, just like A=abcd1234, how to get the abcd1234 and input in file2?

File1:

A=abc1234d
B=qwer1234

File2:

var1=$A
var2=$B

echo $var1
echo $var2

Thanks a lot!

What's the difference? Try the solutions proposed...

Maybe we have not been clear. There is obviously a language barrier here.

You cannot have a space character in a shell variable name. So you cannot have a variable named server name .

If you change file1 to contain the text:

hostname=abcd1234
server_name=qwer1234

then if you change the contents of file2.sh as Walter Misar suggested to:

#!/bin/sh

. ./file1

var1=$hostname
var2=$server_name

echo $var1
echo $var2

and run your script, it should print:

abcd1234
qwer1234

If this isn't what you are trying to do, we have completely misunderstood what you are trying to accomplish.

Thank you, the . ./file1 works