Troubleshooting Unwanted Character Insertion in Putty

When using PuTTY, a popular SSH client for Windows, many users have experienced frustrating issues with random characters being inserted at the cursor. This phenomenon can occur even when no keys are pressed, resulting in unexpected output or changes to the data being edited. In this article, we will explore a solution that has been found effective by some users, known as 'Caffeine,' which can help alleviate this issue.

The Problem

One user's experience with PuTTY highlights the problem: random characters would occasionally appear at the cursor when focused on the window, whether typing or away from the keyboard. The characters could be tildes (~), escape sequences (e.g., ''8', or even single characters. This behavior was inconsistent and seemed to occur without warning.

Caffeine Solution

To prevent this unwanted character insertion in Putty, a user has suggested using Caffeine, an application that sends virtual-key codes to Windows. By applying the Caffeine solution between steps 2 and 3 with the -key:0E parameter (e.g., caffeine.exe 5 -key:0E for easy testing or caffeine.exe 50 -key:0E for a mandatory screen saver set at 1 minute), no keystrokes are received by PuTTY every 5 or 50 seconds. This solution prevents Windows from going to sleep or idle and does not generate any side effects on the system.

Other Solutions

Another user, shreyansp, has found an alternative solution that may be more effective for some users. However, this solution requires further testing and experimentation to determine its efficacy.

If you're experiencing unwanted character insertion in PuTTY, Caffeine may be a viable solution to try. By applying the suggested parameters and using Caffeine between steps 2 and 3, you can potentially eliminate this frustrating issue. While YMMV (your mileage may vary), hope is that this solution will prove helpful for others seeking a remedy.

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