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How to search for a specific text in a file in Kotlin

How to search for a specific text in a file in Kotlin.

Here's a step-by-step tutorial on how to search for a specific text in a file using Kotlin.

Step 1: Import the necessary packages​

To perform file operations in Kotlin, we need to import the java.io package. Add the following line at the top of your Kotlin file:

import java.io.File

Step 2: Create a function to search for text in a file​

Next, create a function that takes the path to the file and the text to search as parameters. This function will read the file line by line and check if the specified text exists in any of the lines. Add the following code to your Kotlin file:

fun searchInFile(filePath: String, searchText: String) {
    val file = File(filePath)
    
    if (file.exists()) {
        file.forEachLine { line ->
            if (line.contains(searchText)) {
                println("Found at line: $line")
            }
        }
    } else {
        println("File not found!")
    }
}

Step 3: Call the search function​

Now, you can call the searchInFile function with the file path and the text you want to search for. For example:

val filePath = "path/to/your/file.txt"
val searchText = "example"

searchInFile(filePath, searchText)

Replace "path/to/your/file.txt" with the actual path to your file, and "example" with the text you want to search for.

Step 4: Handle exceptions​

When working with files, it's important to handle exceptions that may occur. Add try-catch blocks to handle any potential FileNotFoundException or IOException:

fun searchInFile(filePath: String, searchText: String) {
    try {
        val file = File(filePath)

        if (file.exists()) {
            file.forEachLine { line ->
                if (line.contains(searchText)) {
                    println("Found at line: $line")
                }
            }
        } else {
            println("File not found!")
        }
    } catch (e: FileNotFoundException) {
        println("File not found!")
    } catch (e: IOException) {
        println("Error reading the file!")
    }
}

Step 5: Test the code​

Save the Kotlin file and run it. The program will search for the specified text in the file and print the lines where the text is found.

That's it! You have successfully implemented a text search functionality in Kotlin. You can now search for specific text in any file using the searchInFile function.

Here's the complete code:

import java.io.File
import java.io.FileNotFoundException
import java.io.IOException

fun searchInFile(filePath: String, searchText: String) {
    try {
        val file = File(filePath)

        if (file.exists()) {
            file.forEachLine { line ->
                if (line.contains(searchText)) {
                    println("Found at line: $line")
                }
            }
        } else {
            println("File not found!")
        }
    } catch (e: FileNotFoundException) {
        println("File not found!")
    } catch (e: IOException) {
        println("Error reading the file!")
    }
}

fun main() {
    val filePath = "path/to/your/file.txt"
    val searchText = "example"

    searchInFile(filePath, searchText)
}

Remember to replace "path/to/your/file.txt" with the actual path to your file and "example" with the desired text to be searched.