Can now build multiple performance logs

`make perf` will build, by default, perf.log, but you may also build perf.*;
for example:

  $ make perf.1
  # make some changes
  $ make perf.2

This allows comparing changes easily.

.gitignore

@@ -19,7 +19,7 @@ configure
 config.*
 
 # script output
-perf.out
+perf.*
 
 # should be added using autoreconf -i
 INSTALL

Makefile.am

@@ -112,9 +112,10 @@ test: check
 check: $(src_tests) test-suite
 
 # performance tests
-perf:
+perf: perf.log
+perf.%: FORCE
 if HAS_NODE
-	@$(path_test)/perf/runner @PERF_TESTS@
+	@$(path_test)/perf/runner @PERF_TESTS@ > "$@"
 else
 	@echo "Node.js must be installed in order to run performance tests"
 	@exit 1

test/perf/runner.in

@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/bash
 #
 #  Copyright (C) 2014 Mike Gerwitz
 #
@@ -21,16 +21,10 @@
 #   $ column -ts\| perf.out
 # #
 
-rawout=perf.out
->"$rawout"
-
 for f in "$@"; do
   @NODE@ "$f" || exit $?
 done \
-  | tee -a "$rawout" \
-  | awk -F\| '
+  | tee >( awk -F\| '
     # format for display as the tests are running
     { printf "%s (x%s = %ss each): %s\n", $4, $2, $3, $1 }
-  '
-
-echo "Raw data written to $rawout" >&2
+  ' >&2 )