Question

我编写了一个脚本，用于将文件从一台服务器传输到另一台服务器。

首先，我在一台服务器上创建所有压缩文件的tar，然后将tar转移到另一台服务器。

成功转移后，我在服务器上进行文件解压缩。

我需要知道一件事，如果无论如何tar文件损坏传输失败，我如何使用Unix TRAP功能处理Restartability和Errors。

如果存在任何错误，我需要将执行恢复到初始状态。

下面提到的是我脚本中的一小段代码

tar -cvf files_to_send.tar *.txt -C ${1} 
          RC=$?
          if [ ${RC} -ne 0 ]; then
             echo "Unable to Create Tar files of received files" >> ${LOG_FILE}
             rm -f *_end >> ${LOG_FILE}
             return 1
          fi

          cd ${1}
          gzip files_to_send.tar
          RC=$?
          if [ ${RC} -ne 0 ]; then
             echo "Unable to Create Zip of tar files" >> ${LOG_FILE}
             echo "Deleting End Files" >> ${LOG_FILE}
             rm -f *_end >> ${LOG_FILE}
             echo "Deleting tar file" >> ${LOG_FILE}
             rm -f ${1}/files_to_send.tar >> ${LOG_FILE}
             return 1
          fi


          cd ${1}
          chmod 775 files_to_send.tar.gz  >> ${LOG_FILE}
          RC=$?

          if [ ${RC} -ne 0 ]; then
             echo "Unable to change permissions of tar and end files" > ${LOG_FILE}
             echo "Deleting End Files" >> ${LOG_FILE}
             rm -f *_end >> ${LOG_FILE}
             echo "Deleting Zipped tar file" >> ${LOG_FILE}
             rm -f ${SOURCE_DIR}/files_to_send.tar.gz >> ${LOG_FILE}
             return 1

Answer 1

您可以这样做：

trap 'do_something' ERR # start special error handling
tar ... # if the command fails, do_something will be executed
trap - ERR # stopping special error handling

do_something可以是函数，命令或脚本。

但如果你正确处理错误案例，你甚至不需要trap。我用布尔逻辑编写了一个脚本版本，无需将返回代码存储在变量中，请参阅：

if tar -cvf files_to_send.tar *.txt -C ${1}; then
    echo "Unable to Create Tar files of received files" >> ${LOG_FILE}
    rm -f *_end >> ${LOG_FILE}
    return 1
fi

cd ${1}

if gzip files_to_send.tar; then
    echo "Unable to Create Zip of tar files" >> ${LOG_FILE}
    echo "Deleting End Files" >> ${LOG_FILE}
    rm -f *_end >> ${LOG_FILE}
    echo "Deleting tar file" >> ${LOG_FILE}
    rm -f ${1}/files_to_send.tar >> ${LOG_FILE}
    return 1
fi


cd ${1}
if chmod 775 files_to_send.tar.gz >> ${LOG_FILE}; then
    echo "Unable to change permissions of tar and end files" > ${LOG_FILE}
    echo "Deleting End Files" >> ${LOG_FILE}
    rm -f *_end >> ${LOG_FILE}
    echo "Deleting Zipped tar file" >> ${LOG_FILE}
    rm -f ${SOURCE_DIR}/files_to_send.tar.gz >> ${LOG_FILE}
    return 1
fi

在Unix脚本中使用陷阱

1 个答案: