Background: sometimes I use `ps aux | grep process_name` to figure out some statistics of a process. But I can't remember the headers of ps output. So I need to do:

```
ps aux | tee 1.txt | grep process_name > 2.txt
cat 1.txt | head -1 | cat - 2.txt

```

So my questions is: is there a way to achieve this without the two temporary files, and preferably use one line of commands instead of two lines?