bash shell 脚本：预期的整数表达式
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shell script: integer expression expected
提问by Shailendra Rajput
#!/bin/bash
if [$# -ne 1];
then
echo "/root/script.sh a|b"
else if [ ='a'];
then
echo "b"
else if [ ='b']; then
echo "a"
else
echo "/root/script.sh a|b"
fi
I'm getting below error while run above script in Linux.
在 Linux 中运行上述脚本时出现以下错误。
bar.sh: line 2: [: S#: integer expression expected
a
Could you please help to remove this error?
你能帮忙消除这个错误吗？
回答by Rayne
if [$# -ne 1];
[and ]requires spacing. Example:
[并且]需要间距。例子：
if [ $# -ne 1 ];
And else ifshould be elif
并且else if应该是elif
#!/bin/bash
if [ "$#" -ne 1 ];
then
echo "/root/script.sh a|b"
elif [ "" ='a' ];
then
echo "b"
elif [ "" ='b' ]; then
echo "a"
else
echo "/root/script.sh a|b"
fi
Do not forget to quote variables. It is not every time necessary, but recommended.
不要忘记引用变量。并非每次都需要，但建议这样做。
Question: Why do i have -1?
问题：为什么我有-1？
回答by chrisaycock
Bash doesn't allow else if. Instead, use elif.
Bash 不允许else if. 相反，使用elif.
Also, you need spacing within your [...]expression.
此外，您需要在[...]表达式中使用间距。
#!/bin/bash
if [ $# -ne 1 ];
then
echo "/root/script.sh a|b"
elif [ ='a' ];
then
echo "b"
elif [ ='b' ]; then
echo "a"
else
echo "/root/script.sh a|b"
fi
