metaprogramming with awk :))

update_scripts.awk

#!/usr/bin/awk -f

## gawk -i inplace -f update_scripts.awk scripts*.r

## some scripts define output variable without spaces
/^my_variable=/ && NF == 1 {
	split($0, myvar, "=")
	$1 = myvar[1]
	$2 = "="
	$3 = myvar[2]
}

## add scratch to output paths
$1 == "my_variable" && $3 !~ /paste0/ {
	add_scratch = "paste0(Sys.getenv(\"SCRATCHDIR\"), \"/\", " $3 ")"
	$3 = add_scratch
}

## print the script
{print}

rewritting R scripts with awk

I had to run hundreds of scripts for my colleague at a large HPC. Her scripts were written for a smaller server, while I needed to use features like scratch drives. To update all the scripts (which were coming in batches by dozens) on demand, I've made a simple awk script to inject a shell variable into her output path (luckily, my colleague made it easy by setting the same variable near the top of each script; except later she changed the assignment style, so I needed to address that too).