Improve align() by using process substitution (replace named pipe)

[pfxuan]

Hi @cc2qe , I created a patch for aligh(), which also can apply to realigh(). I found this patch can:

• simplify implementation
• avoid to create intermediate named pipes
• slightly improve performance

Running time of named pipe on default example:

real    0m12.965s
user    0m13.404s
sys 0m0.958s

Running time of process substitution on default example:

real    0m12.304s
user    0m13.087s
sys 0m0.895s