Jenkins部署脚本问题：Version与BuildNumber分支逻辑失效排查

问题根源 #

你的脚本里[ -n $Version ]和[ -n $BuildNumber ]的写法存在隐患——当变量未定义或为空时，展开后会变成[ -n ]，而test命令（即[ ]）会把-n当作非空字符串处理，导致无论变量是否有值，if分支的条件都会判定为真。这就是传入BuildNumber时依然走if分支的核心原因。

修复方案：给变量加双引号 #

给变量加上双引号，确保空变量展开后是明确的空字符串，test命令才能正确判断：

#!/bin/bash
if [ -n "$Version" ]; then
    echo "Version is present"
    curl http://localhost:8080/artifactoryservices/artifactory/downloadArtifact/"${Version}"
elif [ -n "$BuildNumber" ]; then
    echo "BuildNumber is Present"
    curl http://localhost:8080/artifactoryservices/artifactory/downloadArtifact/"${BuildNumber}"
else
    echo "No Version or Build Number found"
fi

替代实现方式 #

方式1：使用Bash扩展测试[[ ]] #

Bash的[[ ]]语法更安全，无需担心变量空值展开的问题，写法也更简洁：

#!/bin/bash
if [[ -n $Version ]]; then
    echo "Version is present"
    curl http://localhost:8080/artifactoryservices/artifactory/downloadArtifact/${Version}
elif [[ -n $BuildNumber ]]; then
    echo "BuildNumber is Present"
    curl http://localhost:8080/artifactoryservices/artifactory/downloadArtifact/${BuildNumber}
else
    echo "No Version or Build Number found"
fi

方式2：严格检查变量存在性（Bash 4.2+） #

如果需要区分“变量未定义”和“变量为空字符串”，可以用-v选项检查变量是否存在：

#!/bin/bash
if [[ -v Version && -n $Version ]]; then
    echo "Version is present"
    curl http://localhost:8080/artifactoryservices/artifactory/downloadArtifact/${Version}
elif [[ -v BuildNumber && -n $BuildNumber ]]; then
    echo "BuildNumber is Present"
    curl http://localhost:8080/artifactoryservices/artifactory/downloadArtifact/${BuildNumber}
else
    echo "No Version or Build Number found"
fi

方式3：合并逻辑简化代码 #

如果两个curl的URL结构一致，可通过变量替换简化代码：

#!/bin/bash
ARTIFACT_ID=""
if [ -n "$Version" ]; then
    ARTIFACT_ID="$Version"
elif [ -n "$BuildNumber" ]; then
    ARTIFACT_ID="$BuildNumber"
fi

if [ -n "$ARTIFACT_ID" ]; then
    echo "Using artifact ID: $ARTIFACT_ID"
    curl http://localhost:8080/artifactoryservices/artifactory/downloadArtifact/"${ARTIFACT_ID}"
else
    echo "No Version or Build Number found"
fi

内容的提问来源于stack exchange，提问作者Vishal