Using shell script in node

background

In development, we may need some scripts to batch process our business logic in specific situations. How to call shell scripts in nodejs?

newly build

1. Create a new script file under the project

   touch newFile.sh

2. Modify file permissions

   chmod 777 newFile.sh Modify the file to be readable, writable and executable

Nodejs call

File reading

//Using the file reading method in the child process of nodejs

const { execFile } = require(‘child_process’);

Examples

DocsService.publishAllDocs = (req, res) => {
  req.session.touch();
  const { docName, pathName, saveDocsList, docType } = req.body;
  var docText = req.body.docText;
  var newGit = req.body.newGit;
  //Get file path
  var filepath = path.join(__dirname, '../../bin/rnsource/publishAllDocs.sh');
  var fileArr, fileName, spath, dirnameBack, docbackList = [], docbackPath, docPath = "";
  var username = req.session.user_name;
  var str = docName+'/'+ pathName + '|'+ username;
  var reg = new RegExp(`^(${str})`);
  saveDocsList.map((item, index)=>{
      fileArr = item.pathName.split("/");
      fileName = fileArr[fileArr.length-1];
      if(docType == "docsify"){
          dirnameBack = fileName != "" ? `../../gitlib/docBackup/${docName}/docs/${item.pathName}`:`../../gitlib/docBackup/${docName}/docs/README.md`
      }else{
          spath = item.pathName.split(fileName)[0];
          dirnameBack = spath != "" ?'../../gitlib/docBackup/'+ docName+'/'+ spath +'/'+fileName:'../../gitlib/docBackup/'+ docName+'/' + fileName;  
      }

      docbackPath = path.join(__dirname, dirnameBack);
      docbackList.push(docbackPath);
      docPath +=  docbackPath + " ";
  })
  docPath += ""
  //CWD sets the current path. What I set here is the current location of nodejs code
  execFile(filepath, [docName, docPath, docType], { cwd: '.' }, function(err, stdout, stderr){
      logger.info(stdout);
      if(err){
          loggerFileError({ user:username , docName:docName , pathname: 'all', operate: "gitbook file one click publishing", err});
          res.json({
              respCode: -1,
              Errmsg: "one click publish failed"
          })
      }else{
          res.json({
              respCode: 0,
              MSG: "one click publishing succeeded"
          })
          gitPush({ docName, fileName, docbackPath: docbackList, username, pathName, docType })
          unblockFile({ docName, username, pathName, reg });
      }
  }) 
}

Callback

Successful execution will return the command executed by the script

execFile

• The first parameter: the external program to call, here is the file to read
• The second parameter: the parameter passed to the external program (must be placed in the array)
• The third parameter: callback function, in which the execution result of external program can be returned

shell

publishAllDocs.sh Idea: all the scripts described here are shell scripts not in windows. Bat scripts in windows are not explained here

#$1 document outermost directory $2 currently modified file name $3 currently modified file directory
cd $(pwd)/gitlib/docs/$1
echo "come in"
for item in $2; do
    echo "${item}"
    cp -f ${item} ${item/docBackup/docs}
done
#Echo "initialization entry"
echo "$(pwd)/gitlib/docs/$1"
if [ "$3" == "docsify" ];then
    #Copy the files in the specified directory, such as $1 / $3 / $2 docs / CST / 7e4ce1de04621e0b/
    #Such as CP - RF.. /. / DocBackup / wireless / docs / CST / 7e4ce1de04621e0b / 10708d589 eedfffd.md  ./docs/cst/7e4ce1de04621e0b/
    cp -rf ./docs ../../../public/docs/$1
else
    #Handling gitbook type documents
    gitbook build
    Echo "copy document"
    cp -rf ./_book/* ../../../public/docs/$1
fi

Parameter receiving

• The parameters are obtained according to the data transferred during business call
• Directly use “$” to get
• The order of data acquisition is the order of data transmission
• Remember that it’s not the value of the array corner, and the first parameter of the array is $1

The use of for loop

• Using the form for… In in shell

• Example of loop body data requiring loop

  "/Users/Desktop/work/docManager/docServer/gitlib/docBackup/mygitbook/docs/d09985fc67088b35/d09985fc67088b35.md /Users/Desktop/work/docManager/docServer/gitlib/docBackup/mygitbook/docs/d09985fc67088b35/d09985fc67088b35/6f7a2c61c9bac0a3.md /Users/Desktop/work/docManager/docServer/gitlib/docBackup/mygitbook/README.md /Users/Desktop/work/docManager/docServer/gitlib/docBackup/mygitbook/docs/d09985fc67088b35/d09985fc67088b35/6f7a2c61c9bac0a3.md "

• The data of the loop body in the shell script is special, not our regular array or JSON
• Directly is a string separated by spaces, such as: “a B C D E”

##$2 is the data that is spliced according to the format of the service parameters received in the script, as shown in the above data example
##Loop for... In remember that you must add do to execute the loop body and use done to end the loop
##Each subitem of the item loop body, such as: users / desktop / work / docmanager / docserver / gitlib / DocBackup / mygitbook / docs / d09985fc67088b35 / d09985fc67088b35.md
for item in $2; do
    echo "${item}"
    cp -f ${item} ${item/docBackup/docs}
done
##${item / DocBackup / docs} string replacement
##Here, replace DocBackup in the item path with docs. For a detailed explanation, please see the following shell string replacement

Shell specifies string substitution

In JS, we can use replace to replace strings. How to implement the change in shell?

Example:

string “abc12342341”

• Echo ${string / 23 / BB} / / abc1bb42341 replace once
• Echo ${string / / 23 / BB} / / abc1bb4bb41 double slashes replace all matches
• Echo ${string / # ABC / BB} / / bb12342341 # start with what to match, the ^ in root PHP is a bit like
• echo ${string/%41/bb}//What does abc123423bb% end with? The $in root PHP is a bit like that

The use of if condition judgment

grammar

if[];then
    ...
else
    ...
fi

Examples

##Conditional judgment is to use [] instead of ()
##Add after;
if [ "$3" == "docsify" ];then
    #Copy the files in the specified directory, such as $1 / $3 / $2 docs / CST / 7e4ce1de04621e0b/
    #Such as CP - RF.. /. / DocBackup / wireless / docs / CST / 7e4ce1de04621e0b / 10708d589 eedfffd.md  ./docs/cst/7e4ce1de04621e0b/
    cp -rf ./docs ../../../public/docs/$1
else
    #Handling gitbook type documents
    gitbook build
    Echo "copy document"
    cp -rf ./_book/* ../../../public/docs/$1
fi

be careful

• “Double quotation marks” should be used for string in condition judgment
• If there is a variable (string) in the condition judgment, the variable should also be added with “” double quotation marks
• Conditional judgment should be added after, and then should be used to continue execution
• Fi should be used at the end of conditional judgment