#!/bin/bash

# usage: counter name
#
# Establish or increment a named counter.  Successive calls with the
# same name return values 1, 2, 3, etc.

COUNTERROOT="/tmp/counter-"
file="$COUNTERROOT$1"

if [[ ! -e "$file" ]];then
  value=0
else
  value="$(< "$file")"
fi

value="$((value+1))"

echo "$value" | tee "$file"