The $usearch environment variable
Bash scripts in the OTU / denoising tutorials require an environment variable called $usearch, which must be set to a valid name for the usearch command. For example, a script might show the usearch version by doing this:$usearch -version
You must set the usearch environment variable before running a tutorial script .
You can use the bash export command to set the variable. For convenience, you can put the export command in your ~/.bash_profile and ~/.bashrc files so that it is set every time you start a bash shell.
Usually, it's a good idea to use the full path name to the usearch binary file starting from the root so that the path starts with a forward slash. This will work regardless of your current directory and which directories are in your $PATH variable.
Example