[Home](./index.md) > [bitburner](./bitburner.md) > [NS](./bitburner.ns.md) > [fileExists](./bitburner.ns.fileexists.md) ## NS.fileExists() method Check if a file exists. **Signature:** ```typescript fileExists(filename: string, host?: string): boolean; ``` ## Parameters | Parameter | Type | Description | | --- | --- | --- | | filename | string | Filename of file to check. | | host | string | _(Optional)_ Host of target server. Optional, defaults to the server the script is running on. | **Returns:** boolean True if specified file exists, and false otherwise. ## Remarks RAM cost: 0.1 GB Returns a boolean indicating whether the specified file exists on the target server. The filename for programs is case-insensitive, other file types are case-sensitive. For example, fileExists(“brutessh.exe”) will work fine, even though the actual program is named 'BruteSSH.exe'. ## Example ```js // The function call will return true if the script named foo.js exists on the foodnstuff server, and false otherwise. ns.fileExists("foo.js", "foodnstuff"); // The function call will return true if the current server contains the FTPCrack.exe program, and false otherwise. ns.fileExists("ftpcrack.exe"); ```