# How can I delete a file from inside a task?
**URL:** https://discuss.gradle.org/t/how-can-i-delete-a-file-from-inside-a-task/35552
**Category:** Help/Discuss
**Created:** [April 4, 2020, 7:57pm UTC](https://discuss.gradle.org/t/how-can-i-delete-a-file-from-inside-a-task/35552 "2020-04-04T19:57:19Z")
**Posts on this page:** 11
**Page:** 1
### Author:  [@afafefefsaef](https://discuss.gradle.org/u/afafefefsaef)
#### Post date: [April 4, 2020, 7:57pm UTC](https://discuss.gradle.org/t/how-can-i-delete-a-file-from-inside-a-task/35552/1 "2020-04-04T19:57:19Z")
I’m trying to make a custom task, written in Kotlin, that generates a file through a commandline command. The problem is that this the external commandline program can’t handle if the generated file already exists.
So, what I am trying to do inside my `@TaskAction` is to delete the contents of the output directory before running the command.
I tried to do the following, but I get Gradle import errors and Project resolve errors.
```gradle
project.delete(
fileTree("${project.buildDir}/jpackageAppImage")
)
```
When I look in the [docs for delete](https://docs.gradle.org/current/javadoc/org/gradle/api/Project.html#delete-java.lang.Object...-), it says that the input to that function can be
> Any type of object accepted by [`files(Object...)`](https://docs.gradle.org/current/javadoc/org/gradle/api/Project.html#files-java.lang.Object...-)
When I look at the [docs for files](https://docs.gradle.org/current/javadoc/org/gradle/api/Project.html#files-java.lang.Object...-), it says it accepts a a `FileTree`
Can anyone help me out with this?
---
### Author:  [@shadowface](https://discuss.gradle.org/u/shadowface)
#### Post date: [April 4, 2020, 8:45pm UTC](https://discuss.gradle.org/t/how-can-i-delete-a-file-from-inside-a-task/35552/2 "2020-04-04T20:45:20Z")
try
```gradle
project.delete(
files("${project.buildDir}/jpackageAppImage")
)
```
Or define your own task
```gradle
task deleteMyFile(type: Delete) {
paths files("${project.buildDir}/jpackageAppImage")
}
```
---
### Author:  [@afafefefsaef](https://discuss.gradle.org/u/afafefefsaef)
#### Post date: [April 4, 2020, 8:58pm UTC](https://discuss.gradle.org/t/how-can-i-delete-a-file-from-inside-a-task/35552/3 "2020-04-04T20:58:57Z")
The first one
```gradle
project.delete(
files("${project.buildDir}/jpackageAppImage")
)
```
Causes the same problem 😑
---
### Author:  [@shadowface](https://discuss.gradle.org/u/shadowface)
#### Post date: [April 4, 2020, 9:27pm UTC](https://discuss.gradle.org/t/how-can-i-delete-a-file-from-inside-a-task/35552/4 "2020-04-04T21:27:32Z")
this should work
```gradle
task myDeleteTask(type: Delete) {
delete files("${buildDir}/jpackageAppImage")
}
```
---
### Author:  [@afafefefsaef](https://discuss.gradle.org/u/afafefefsaef)
#### Post date: [April 4, 2020, 10:07pm UTC](https://discuss.gradle.org/t/how-can-i-delete-a-file-from-inside-a-task/35552/5 "2020-04-04T22:07:06Z")
Running it as a separate task worked. However, I don’t want to have to remember to create a separate delete task every time I want to create an installer task.
```gradle
tasks.register("deleteJpackageImage") {
delete(files("${project.buildDir}/jpackageAppImage"))
}
```
I’d really like to be able to just have the Installer task work without any outside logic. Also, I’d like to understand why `delete` inside of my task is failing so that I can have a better understanding of Gradle.
---
### Author:  [@shadowface](https://discuss.gradle.org/u/shadowface)
#### Post date: [April 4, 2020, 10:13pm UTC](https://discuss.gradle.org/t/how-can-i-delete-a-file-from-inside-a-task/35552/6 "2020-04-04T22:13:52Z")
For `Delete` task you need to comply with gradle `Api` that’s why you had to create a new task that overrides the `Delete` default task from gradle.
if you want to register a task that works with `install` task you can do like this
```gradle
task myDeleteTask(type: Delete) {
delete files("${buildDir}/jpackageAppImage")
}
myDeleteTask.mustRunAfter installerTask
```
`installerTask` is your custom installer task.
`mustRunAfter` is a gradle Api that allows to you chain tasks
---
### Author:  [@shadowface](https://discuss.gradle.org/u/shadowface)
#### Post date: [April 4, 2020, 10:30pm UTC](https://discuss.gradle.org/t/how-can-i-delete-a-file-from-inside-a-task/35552/8 "2020-04-04T22:30:17Z")
You can do as follows
```gradle
task installerTask() {
//.... your task logic goes here
doLast {
delete("${buildDir}/jpackageAppImage")
}
}
```
---
### Author:  [@afafefefsaef](https://discuss.gradle.org/u/afafefefsaef)
#### Post date: [April 4, 2020, 11:15pm UTC](https://discuss.gradle.org/t/how-can-i-delete-a-file-from-inside-a-task/35552/9 "2020-04-04T23:15:27Z")
> For `Delete` task you need to comply with gradle `Api` that’s why you had to create a new task that overrides the `Delete` default task from gradle.
So `Project.delete()` can only be used inside of tasks that inherit from `org.gradle.api.tasks.Delete`?
---
### Author:  [@shadowface](https://discuss.gradle.org/u/shadowface)
#### Post date: [April 5, 2020, 12:22am UTC](https://discuss.gradle.org/t/how-can-i-delete-a-file-from-inside-a-task/35552/10 "2020-04-05T00:22:33Z")
`project.Delete()` cannot be called from outside a task or a buildScript. It also requires a path to your `File` or `Dir`
---
### Author:  [@afafefefsaef](https://discuss.gradle.org/u/afafefefsaef)
#### Post date: [April 5, 2020, 12:59am UTC](https://discuss.gradle.org/t/how-can-i-delete-a-file-from-inside-a-task/35552/11 "2020-04-05T00:59:15Z")
> `project.Delete()` cannot be called from outside a task or a buildScript. It also requires a path to your `File` or `Dir`
Right, so why doesn’t it work when I do this inside a custom task inside my `build.gradle.kts`
```gradle
open class WindowsInstaller () : DefaultTask() {
...
@TaskAction
fun generateWindowsInstaller() {
project.delete(
fileTree("${project.buildDir}/jpackageAppImage")
)
...
}
...
}
```
Unless I am misunderstanding something, [according to the docs](https://docs.gradle.org/current/javadoc/org/gradle/api/Project.html#delete-java.lang.Object...-) it should work.
---
### Author:  [@afafefefsaef](https://discuss.gradle.org/u/afafefefsaef)
#### Post date: [April 5, 2020, 2:00am UTC](https://discuss.gradle.org/t/how-can-i-delete-a-file-from-inside-a-task/35552/12 "2020-04-05T02:00:25Z")
It looks like my mistake was that I needed to do `project.fileTree` instead of just `fileTree`.
```gradle
open class WindowsInstaller () : DefaultTask() {
...
@TaskAction
fun generateWindowsInstaller() {
project.delete(
project.fileTree("${project.buildDir}/jpackageAppImage")
)
...
}
...
}
```