Write a string to a file - Bun

Write a string to a file - BunDocumentation Index

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Skip to main contentBun home pageSearch...⌘KInstall BunSearch...NavigationFile SystemWrite a string to a fileRuntimePackage ManagerBundlerTest RunnerGuidesReferenceBlogFeedback:first-child]:!hidden peer-[.is-custom]:[&>:first-child]:sm:!hidden peer-[.is-custom]:[&>:first-child]:md:!hidden peer-[.is-custom]:[&>:first-child]:lg:!hidden peer-[.is-custom]:[&>:first-child]:xl:!hidden">OverviewGuidesDeploymentDeploy on VercelDeploy on RailwayDeploy on RenderDeploy on AWS LambdaDeploy on DigitalOceanDeploy on Google Cloud RunRuntime & DebuggingTypeScript typesRe-map import pathsVS Code debuggerWeb debuggerHeap snapshotsBuild-time constantsDefine constantsGitHub ActionsCodesign on macOSUtilitiesUpgrade BunDetect BunGet Bun versionHash passwordGenerate UUIDBase64 encodingGzip compressionDEFLATE compressionEscape HTMLDeep equalitySleepFile URL to pathPath to file URLFind executable pathimport.meta.dirimport.meta.fileimport.meta.pathCheck entrypointGet entrypoint pathEcosystem & FrameworksAstro 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using IPCListen for CTRL+COS signalsProcess uptimeRun shell commandSet time zoneSet env variablesRead env variablesPackage ManagerAdd a dependencyAdd a dev dependencyAdd an optional dependencyAdd a peer dependencyAdd a Git dependencyAdd a tarball dependencyInstall with aliasWorkspaces with BunOverride the default npm registryConfigure a scoped registryAzure Artifacts with BunJFrog Artifactory with BunAdd a trusted dependencyGenerate a yarn-compatible lockfileMigrate from npm to bunConfigure git to diff Bun's lockfileInstall Bun in GitHub ActionsTest RunnerRun testsWatch modeMigrate from JestMock functionsSpy on methodsMock system timeSnapshot testingUpdate snapshotsCoverage reportsCoverage thresholdConcurrent test globSkip testsTodo testsTest timeoutBail earlyRe-run testsTesting LibraryDOM testsTest SvelteRuntime & DebuggingVS Code debuggerWeb debuggerHeap snapshotsBuild-time constantsDefine constantsGitHub ActionsCodesign on macOSModule SystemImport JSONImport TOMLImport YAMLImport JSON5Import HTMLimport.meta.dirimport.meta.fileimport.meta.pathCheck entrypointGet entrypoint pathFile SystemRead as stringRead to BufferRead to Uint8ArrayRead to ArrayBufferRead JSON fileGet MIME typeCheck file existsWatch directoryRead as streamWrite string to fileWrite BlobWrite ResponseAppend to fileIncremental writeWrite streamWrite to stdoutWrite file to stdoutCopy fileDelete fileDelete filesDelete directoriesUtilitiesHash passwordGenerate UUIDBase64 encodingGzip compressionDEFLATE compressionEscape HTMLDeep equalitySleepFile URL to pathPath to file URLFind executable pathHTML ProcessingExtract links using HTMLRewriterOpenGraph tagsBinary DataArrayBuffer to stringArrayBuffer to BufferArrayBuffer to BlobArrayBuffer to ArrayArrayBuffer to Uint8ArrayBuffer to stringBuffer to ArrayBufferBuffer to BlobBuffer to Uint8ArrayBuffer to ReadableStreamBlob to stringBlob to ArrayBufferBlob to Uint8ArrayBlob to DataViewBlob to ReadableStreamUint8Array to stringUint8Array to ArrayBufferUint8Array to BufferUint8Array to BlobUint8Array to DataViewUint8Array to ReadableStreamDataView to stringStreamsStream to stringStream to JSONStream to BlobStream to BufferStream to ArrayBufferStream to Uint8ArrayStream to arrayReadable to stringReadable to JSONReadable to BlobReadable to Uint8ArrayReadable to ArrayBufferFile SystemWrite a string to a fileCopy pagespan]:line-clamp-1 overflow-hidden group flex items-center py-0.5 gap-1 text-sm text-gray-950/50 dark:text-white/50 group-hover:text-gray-950/70 dark:group-hover:text-white/70 rounded-none rounded-r-xl border px-3 border-gray-200 aspect-square dark:border-white/[0.07] bg-background-light dark:bg-background-dark hover:bg-gray-600/5 dark:hover:bg-gray-200/5" aria-label="More actions" type="button" id="radix-_R_n4ctdbsnlht5lebsnpfdb_" aria-haspopup="menu" aria-expanded="false" data-state="closed">Copy pagespan]:line-clamp-1 overflow-hidden group flex items-center py-0.5 gap-1 text-sm text-gray-950/50 dark:text-white/50 group-hover:text-gray-950/70 dark:group-hover:text-white/70 rounded-none rounded-r-xl border px-3 border-gray-200 aspect-square dark:border-white/[0.07] bg-background-light dark:bg-background-dark hover:bg-gray-600/5 dark:hover:bg-gray-200/5" aria-label="More actions" type="button" id="radix-_R_1cctdbsnlht5lebsnpfdb_" aria-haspopup="menu" aria-expanded="false" data-state="closed">This code snippet writes a string to disk at a particular absolute path. It uses the fast Bun.write() API to efficiently write data to disk. The first argument is a destination; the second is the data to write.

const path = "/path/to/file.txt";
await Bun.write(path, "Lorem ipsum");

Any relative paths will be resolved relative to the project root (the nearest directory containing a package.json file).

const path = "./file.txt";
await Bun.write(path, "Lorem ipsum");

You can pass a BunFile as the destination. Bun.write() will write the data to its associated path.

const path = Bun.file("./file.txt");
await Bun.write(path, "Lorem ipsum");

Bun.write() returns the number of bytes written to disk.

const path = "./file.txt";
const bytes = await Bun.write(path, "Lorem ipsum");
// => 11

See Docs > API > File I/O for complete documentation of Bun.write().

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