var temp = require('../lib/temp'), fs = require('fs'), util = require('util'), exec = require('child_process').exec; var myData = "foo\nbar\nfoo\nbaz"; temp.open('myprefix', function(err, info) { if (err) throw err; fs.write(info.fd, myData); fs.close(info.fd, function(err) { if (err) throw err; exec("grep foo '" + info.path + "' | wc -l", function(err, stdout) { if (err) throw err; util.puts(stdout.trim()); }); }); });