Finding tools

Where tools are searched for

For each tool, the executable is searched for, in this order:

1. The path in the DiffEngine_<Tool> environment variable, when it is set. See Point to an executable.
2. The usual installation folders of the tool on the current operating system, such as %ProgramFiles%\WinMerge\ on Windows or /Applications/Visual Studio Code.app/Contents/Resources/app/bin/ on macOS. When several versions are installed side by side, such as Beyond Compare 4 and Beyond Compare 5, the folder with the highest version number is used.
3. The folders of the PATH environment variable. On Windows, a name without extension is also tried with each extension of PATHEXT.

Tools are only found on Windows, Linux and macOS. The search reads the file system on each call: when you look for a tool many times, keep the ResolvedTool you get.

Point to an executable

Set DiffEngine_<Tool>, where <Tool> is the name of a DiffTool value, to the path of the executable or to the folder that contains it. Environment variables in the value are expanded, surrounding quotes are removed, and * matches any folder name:

export DiffEngine_BeyondCompare="/opt/beyondcompare/bin/bcompare"
export DiffEngine_VisualStudioCode="$HOME/tools/vscode/bin"

When the variable is set, the installation folders and PATH are not searched for that tool. If the executable cannot be found at that path:

• TryFindByName throws an InvalidOperationException that names the variable, so a typo is not silently ignored;
• TryFindByExtension skips that tool and keeps looking at the others.

Swap the sides of the diff

By default, GetArguments(tempFile, targetFile) puts the new content on the left and the target file on the right. Set DiffEngine_TargetOnLeft to true to put the target file on the left:

export DiffEngine_TargetOnLeft=true

The variable is read each time GetArguments is called.

Supported tools

Every tool supports text, except MsWordDiff and MsExcelDiff. The table is in the order TryFindByExtension tries the tools.