如果远程机器上已经存在文件，如何更改文件名? [英] How to change name of file if already present on remote machine?

问题描述

如果某个文件已通过 SSH 存在于远程服务器上，我想更改该文件的名称.

I want to change the name of a file if it is already present on a remote server via SSH.

我从这里尝试了这个(超级用户)

bash
ssh user@localhost -p 2222 'test -f /absolute/path/to/file' && echo 'YES' || echo 'NO'

这适用于提示，文件存在时回显 YES，不存在时回显 NO.但我希望它从 crontab 启动，然后它必须在脚本中.

This works well with a prompt, echoes YES when the file exists and NO when it doesn't. But I want this to be launched from a crontab, then it must be in a script.

假设文件名为 data.csv，在循环中设置一个条件，例如如果服务器上已经有一个 data.csv 文件，则文件将重命名为data_1.csv，然后是data_2.csv，...直到名称唯一.

Let's assume the file is called data.csv, a condition is set in a loop such as if there already is a data.csv file on the server, the file will be renamed data_1.csv and then data_2.csv, ... until the name is unique.

重命名部分有效，但检测部分无效:

The renaming part works, but the detection part doesn't :

while [[ $fileIsPresent!='false' ]]
do
    ((appended+=1))
    newFileName=${fileName}_${appended}.csv

    remoteFilePathname=${remoteFolder}${newFileName}

    ssh pi@localhost -p 2222 'test -f $remoteFilePathname' && fileIsPresent='true' || fileIsPresent='false'
done

始终为任何 data_X.csv 返回 fileIsPresent='true'.所有路径都是绝对路径.

always returns fileIsPresent='true' for any data_X.csv. All the paths are absolute.

你有什么想法可以帮助我吗?

Do you have any idea to help me?

推荐答案

当你寻求帮助你的想法时，我认为值得一提的是，你可能不想启动多达 100 个 ssh 处理每个登录到远程机器的人，所以你可能会用这样的结构做得更好，它只建立一个运行直到完成的 ssh 会话:

As you asked for ideas to help you, I thought it worth mentioning that you probably don't want to start up to 100 ssh processes each one logging into the remote machine, so you might do better with a construct like this that only establishes a single ssh session that runs till complete:

ssh USER@REMOTE <<'EOF'
for ((i=0;i<10;i++)) ; do
  echo $i
done
EOF

---

或者，您可以在本地创建和测试 bash 脚本，然后像这样远程运行它:

---

Alternatively, you can create and test a bash script locally and then run it remotely like this:

ssh USER@REMOTE 'bash -s' < LocallyTestedScript.bash 

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