Is it possible to open a text file with JavaScript (location like http://example.com/directory/file.txt) and check if the file contains a given string/variable?
In PHP this can be accomplished easily with something like:
$file = file_get_contents("filename.ext");
if (!strpos($file, "search string")) {
echo "String not found!";
} else {
echo "String found!";
}
Is there a way to do this? I'm running the "function" in a .js file with Node.js, appfog.
You can not open files client side with javascript.
You can do it with node.js though on the server side.
fs.readFile(FILE_LOCATION, function (err, data) {
if (err) throw err;
if(data.indexOf('search string') >= 0){
console.log(data) //Do Things
}
});
Newer versions of node.js (>= 6.0.0) have the includes function, which searches for a match in a string.
fs.readFile(FILE_LOCATION, function (err, data) {
if (err) throw err;
if(data.includes('search string')){
console.log(data)
}
});
You can also use a stream. They can handle larger files. For example:
var fs = require('fs');
var stream = fs.createReadStream(path);
var found = false;
stream.on('data',function(d){
if(!found) found=!!(''+d).match(content)
});
stream.on('error',function(err){
then(err, found);
});
stream.on('close',function(err){
then(err, found);
});
Either an 'error' or 'close' will occur. Then, the stream will close since the default value of autoClose is true.
Is there a, preferably easy, way to do this?
Yes.
require("fs").readFile("filename.ext", function(err, cont) {
if (err)
throw err;
console.log("String"+(cont.indexOf("search string")>-1 ? " " : " not ")+"found");
});
readFile, or use readFileSync insteadOOP way :
var JFile=require('jfile');
var txtFile=new JFile(PATH);
var result=txtFile.grep("word") ;
//txtFile.grep("word",true) -> Add 2nd argument "true" to ge index of lines which contains "word"/
npm install jfile
((JFile)=>{
var result= new JFile(PATH).grep("word");
})(require('jfile'))
From the client side you can definitely do this :
var xhttp = new XMLHttpRequest(), searchString = "foobar";
xhttp.onreadystatechange = function() {
if (xhttp.readyState == 4 && xhttp.status == 200) {
console.log(xhttp.responseText.indexOf(searchString) > -1 ? "has string" : "does not have string")
}
};
xhttp.open("GET", "http://somedomain.io/test.txt", true);
xhttp.send();
If you want to do it on the server side with node.js use File System package this way :
var fs = require("fs"), searchString = "somestring";
fs.readFile("somefile.txt", function(err, content) {
if (err) throw err;
console.log(content.indexOf(searchString)>-1 ? "has string" : "does not have string")
});
