bash 意外标记“fi”附近的语法错误
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Syntax error near unexpected token 'fi'
提问by Calvin Koder
I'm trying to write a script that removes all the .jpg's that end in an odd number. This is my code:
我正在尝试编写一个脚本来删除所有以奇数结尾的 .jpg。这是我的代码：
#!/bin/bash
echo "start\n"
for f in *.jpg
do
fname=$(basename "$f")
echo "fname is $fname\n"
fname="${filename%.*}"
echo "fname is $fname\n"
if[$((fname % 2)) -eq 1 ] then
echo "removing $fname\n"
rm $f
fi
done
When I run it it outputs start and then says "syntax error near unexpected token 'fi'"
当我运行它时，它输出 start 然后说“意外标记 'fi' 附近的语法错误”
When I had then on the line after if it said "syntax error near unexpected token 'then'"
当我上线后，如果它说“意外标记附近的语法错误'then'”
How do i fix this?
我该如何解决？
回答by jprice
As well as having thenon a new line, you also need a space before and after the [, which is a special symbol in BASH.
除了then换行外，您还需要在 前后留一个空格[，这是 BASH 中的一个特殊符号。
#!/bin/bash
echo "start\n"
for f in *.jpg
do
fname=$(basename "$f")
echo "fname is $fname\n"
fname="${filename%.*}"
echo "fname is $fname\n"
if [ $((fname % 2)) -eq 1 ]
then
echo "removing $fname\n"
rm "$f"
fi
done
回答by Sagar
Use Notepad ++ and use the option to Convert the file to UNIX format. That should solve this problem.
使用 Notepad ++ 并使用将文件转换为 UNIX 格式的选项。那应该可以解决这个问题。
回答by peterh - Reinstate Monica
"Then" is a command in bash, thus it needs a ";" or a newline before it.
“then”是bash中的命令，因此它需要一个“;” 或者它之前的换行符。
#!/bin/bash
echo "start\n"
for f in *.jpg
do
fname=$(basename "$f")
echo "fname is $fname\n"
fname="${filename%.*}"
echo "fname is $fname\n"
if [$[fname%2] -eq 1 ]
then
echo "removing $fname\n"
rm $f
fi
done
回答by Aleks-Daniel Jakimenko-A.
The first problem with your script is that you have to put a space after the [.
Type type [to see what is really happening. It should tell you that [is an alias to testcommand, so [ ]in bash is not some special syntax for conditionals, it is just a command on its own. What you should prefer in bash is [[ ]]. This common pitfall is greatly explained hereand here.
你的脚本的第一个问题是你必须在[.
键入type [以查看实际发生的情况。它应该告诉你这[是test命令的别名，所以[ ]在 bash 中不是一些特殊的条件语法，它本身只是一个命令。在 bash 中你应该更喜欢的是[[ ]]. 这个常见的陷阱在这里和这里都有很好的解释。
Another problem is that you didn't quote "$f"which might become a problem later. This is explained here
另一个问题是您没有引用"$f"这可能会在以后成为问题。这是解释here
You can use arithmetic expressions in if, so you don't have to use [ ]or [[ ]]at all in some cases. More info here
您可以在 中使用算术表达式if，因此在某些情况下您不必使用[ ]或根本不必使用[[ ]]。更多信息在这里
Also there's no need to use \nin every echo, because echoplaces newlines by default. If you want TWO newlines to appear, then use echo -e 'start\n'or echo $'start\n'. This $''syntax is explained here
也不需要\n在 every 中使用echo，因为echo默认情况下会放置换行符。如果您希望出现两个换行符，请使用echo -e 'start\n'或echo $'start\n'。此$''语法解释here
To make it completely perfect you should place --before arbitrary filenames, otherwise rmmight treat it as a parameter if the file name starts with dashes. This is explained here.
为了使其完全完美，您应该将其放在--任意文件名之前，否则rm如果文件名以破折号开头，则可能会将其视为参数。这是解释here。
So here's your script:
所以这是你的脚本：
#!/bin/bash
echo "start"
for f in *.jpg
do
fname="${f##*/}"
echo "fname is $fname"
if (( fname % 2 == 1 )); then
echo "removing $fname"
rm -- "$f"
fi
done
