How to Disable Automatic Scrolling in PuTTY

PuTTY is a popular terminal emulator that allows users to connect to remote servers via SSH, Telnet, or Serial. However, some users may encounter a problem when using PuTTY: the terminal window automatically scrolls to the bottom whenever new output is generated by the running program. This can make it difficult to read the previous output or commands, especially if the program produces a lot of data.

In this article, we will explain how to disable automatic scrolling in PuTTY and how to control the scrolling behavior using keyboard shortcuts or device settings. We will also provide some alternative methods to capture the output of a program without scrolling through the terminal window.

Why Does PuTTY Scroll Automatically?

PuTTY does not have any built-in feature that causes the terminal window to scroll automatically. The scrolling behavior is determined by the remote device that PuTTY is connected to. The device may have a pagination feature that splits the output into pages and pauses after each page, or it may send the output continuously without any pause.

If the device sends the output continuously, PuTTY will try to display the latest output on the terminal window. This means that the terminal window will scroll to the bottom as new output arrives, unless the user manually scrolls up or pauses the output.

How to Disable Automatic Scrolling in PuTTY

There are several ways to disable automatic scrolling in PuTTY and keep the terminal window at a fixed position. Here are some of the most common methods:

Method 1: Uncheck Reset scrollback on display activity option

1. Open PuTTY.
2. In the PuTTY Configuration window, located on the left-hand side, click on the “Window” category.
3. Within the “Window” category, locate the checkbox labeled “Reset scrollback on display activity.”
4. Click on the checkbox to deselect it, removing the checkmark.
5. After unchecking the option, click the “Apply” button at the bottom of the PuTTY Configuration window to save the changes.
6. Optionally, you can click “OK” to close the PuTTY Configuration window if you’ve made all desired changes.

Reference: 4.7.3 Controlling scrollback

Method 2: Pause the Output Using Keyboard Shortcuts

One of the simplest ways to stop PuTTY from scrolling to the bottom is to pause the output using keyboard shortcuts. PuTTY supports the standard XON/XOFF flow control, which means that you can use Ctrl+S to stop the output and Ctrl+Q to resume it. This will let you read the current screen without being interrupted by new output.

However, this method has some limitations. First, it may not work if the remote device does not support XON/XOFF flow control or if it has been disabled. Second, it may cause the program to hang or crash if it depends on the output being sent to the terminal. Third, it will not let you scroll up or down while the output is paused.

Method 3: Change the Device Settings to Disable Pagination

Another way to disable automatic scrolling in PuTTY is to change the device settings to disable pagination. Pagination is a feature that splits the output into pages and pauses after each page, allowing the user to press a key to continue. This can prevent the terminal window from scrolling to the bottom, but it can also be annoying if the user wants to see the whole output at once.

The exact instructions to disable pagination depend on the device’s firmware. Usually, there is a command that can be entered in the device’s shell or configuration mode to change the pagination settings. For example, here are some common commands for different devices:

• ArubaOS: no paging
• Cisco IOS: terminal length 0
• Cisco ASA: terminal pager 0
• HP Comware: screen-length disable
• HP ProCurve: no page
• Palo Alto: set cli pager off
• TP-Link: terminal length 0 (or no clipaging in config mode)

After disabling pagination, the device will send the output continuously without any pause. This means that PuTTY will scroll to the bottom unless the user manually scrolls up or pauses the output.

Method 4: Capture the Output to a File and Download It

A third way to disable automatic scrolling in PuTTY is to capture the output to a file and download it. This can be useful if the user wants to save the output for later analysis or reference, or if the output is too long to fit in the terminal window. This method can also avoid the potential problems of pausing the output or disabling pagination, such as hanging or crashing the program.

To capture the output to a file, the user can use the redirection operator (>) or the append operator (
>>) in the device’s shell or configuration mode. For example, the following command will redirect the output of show running-config to a file named config.txt: show running-config > config.txt
The user can then download the file using a file transfer protocol such as FTP, TFTP, SCP, or SFTP. The exact steps to download the file depend on the device’s firmware and the file transfer protocol. The user may need to enable the file transfer service, specify the file name and path, and provide the login credentials.

Alternatively, the user can also use PuTTY’s session logging feature to capture the output to a file on the local computer. To enable session logging, the user can go to the PuTTY configuration window, select the Session category, click on the Logging sub-category, and choose the desired logging options. The user can then specify the file name and path, and select the format of the log file. PuTTY supports several formats, such as plain text, printable output, or all session output.

Conclusion

In this article, we have explained how to disable automatic scrolling in PuTTY and how to control the scrolling behavior using keyboard shortcuts or device settings. We have also provided some alternative methods to capture the output of a program without scrolling through the terminal window.

We hope that this article has been helpful for users who want to stop PuTTY from scrolling to the bottom automatically when new output is generated by the running program. If you have any questions or feedback, please feel free to leave a comment below.