Bash-比较两个命令的输出

Question

I have this code:

#!/bin/bash

CMDA=$(curl -sI website.com/example.txt | grep Content-Length)

CMDB=$(curl -sI website.com/example.txt | grep Content-Length)

if [ "CMDA" == "CMDB" ];then
  echo "equal";
else
  echo "not equal";
fi

with this output

root@abcd:/var/www/html# bash ayy.sh
not equal

which should be "equal" instead of "not equal". What did I do wrong?

Thnaks

Answer 1

You forgot the $ for the variables CMDA and CMDB there. This is what you need:

if [ "$CMDA" = "$CMDB" ]; then

I also changed the == operator to = , because man test only mentions = , and not == .

Also, you have some redundant semicolons. The whole thing a bit cleaner:

if [ "$CMDA" = "$CMDB" ]; then
  echo "equal"
else
  echo "not equal"
fi

Answer 2

您正在将字符串“ CMDA”与“ CMDB”进行比较，而应使用$来比较变量，例如$ {CMDA}