从外壳程序脚本运行Java时，“没有这样的文件或目录”

Question

I'm trying to run a script from an Amazon Linux machine. The script invokes checkstyle like this (in a script called eval.sh):

CHECKSTYLE="java -jar /home/ec2-user/grader/ext/checkstyle-6.15-all.jar"
CHECKSTYLE_RULES="/home/ec2-user/grader/config/checks.xml"
CHECKSTYLE_OUT="quality.log"
"${CHECKSTYLE}" -c "${CHECKSTYLE_RULES}" -f xml -o "${CHECKSTYLE_OUT}" $(find "${_toCheck}" -name "*.java") 2>"quality.err"

When I run this, I get the following error in quality.err:

 ./grader/eval.sh: line 10: java -jar /home/ec2-user/grader/ext/checkstyle-6.15-all.jar: No such file or directory

I have tried to run the same command directly in the terminal and it is working. Both checkstyle-6.15-all.jar and checks.xml are where they should be.

What could cause this problem?

Answer 1

When you envoke "${CHECKSTYLE}" the shell thinks that is the command you are running. There is no such file name with the spaces and options have you have included there. If you envoke it simply as ${CHECKSTYLE} (drop the quotes) the shell will process it for whitespace as normal and split it into the appropriate pieces for creating the process.

Answer 2

Change "${CHECKSTYLE}" to ${CHECKSTYLE} (without the quotes).

You are passing the entire value of the CHECKSTYLE variable as a single word (that's what the quotes do), so the shell is looking for a relative directory named java -jar , and is trying to find a file under that (nonexistent) directory with the path home/ec2-user/grader/ext/checkstyle-6.15-all.jar .