I'm trying to implement a decent random string generator in my buildfile using the following ExecTask :
<exec command="cat /dev/urandom | tr -cd '[:alnum:]' | fold -w30 | head -n1" returnProperty="random" />
While this works fine when run on the command line, it causes my build script to just hang when I try and call it from Phing. I've tried various escape patterns to no avail. What am I doing wrong?