When you start mothur, you will see a screen that looks like this:
mothur v1.0 Last updated: 1/29/2009 by Patrick D. Schloss Department of Microbiology The University of Massachusetts firstname.lastname@example.org [`https://schloss.micro.umass.edu/mothur`](https://schloss.micro.umass.edu/mothur) Distributed under the GNU General Public License Type 'help()' for information on the commands that are available Type 'quit()' to exit program mothur >
All of your commands will be entered from the mothur prompt. You can get a list of commands by typing help() at the prompt and you can get more specific help for each command by typing command_name(help) at the prompt. For example:
mothur > align.seqs(help)
Would give you the help file information for the align.seqs command.
If you want to quit mothur you simply enter:
mothur > quit()
mothur > quit
With the exception of quit, all commands require you to provide an open and close parentheses. If you supply any options there cannot be a space between the option, the ‘=’, and the option setting. To separate options, use a comma. For example:
mothur > cluster(method=furthest, cutoff=0.10)
Environment variables can be used to generalize variables for reuse. Let’s add environment variables to our analysis.
The format of environmental variables is [tag]=[value]. For example, let’s create a environment variable for the processors option.
mothur will automatically pull in the systems environment variable. For example you can set variables in bash and then run mothur:
. mothurMac-3% export REFERENCE_LOCATION=/Users/sarahwestcott/Desktop/release . mothurMac-3% export ALIGNREF=silva.v4.fasta . mothurMac-3% export TAXONREF_FASTA=trainset9_032012.pds.fasta . mothurMac-3% export TAXONREF_TAX=trainset9_032012.pds.tax . mothurMac-3% export CONTAMINENTS=Chloroplast-Mitochondria-unknown-Archaea-Eukaryota . mothurMac-3% export LOGNAME=MiSEQ_SOP_mouse_03032020 . mothurMac-3% export DATA=/Users/sarahwestcott/Desktop/MiSeq_SOP . mothurMac-3% export TYPE=gz . mothurMac-3% export PROC=12 . mothurMac-3% ./mothur
Type 'quit()' to exit program [note]: Setting random seed to 19760620. mothur > set.logfile(name=$LOGNAME) mothur > set.dir(input=$DATA) . mothur's directories: inputDir=/Users/sarahwestcott/Desktop/MiSeq_SOP
The ‘$’ symbol indicates to mothur that the value is an environment variable to be replaced with the actual value at run time. For example:
PROC=12 make.contigs(file=current, processors=$PROC)
is equivalent to
You can create an environment variable for anything you wish as well as combining variables. For example:
mothur > REFERENCE_LOCATION=/Users/sarahwestcott/Desktop/release Setting environment variable REFERENCE_LOCATION to /Users/sarahwestcott/Desktop/release mothur > ALIGNREF=silva.v4.fasta Setting environment variable ALIGNREF to silva.v4.fasta mothur > align.seqs(fasta=my.fasta, reference=$REFERENCE_LOCATION/$ALIGNREF)