pwd: /out/package
ppid: 1523
   1: WRITELN echo 123 > 1.txt
   2: WRITELN cat < 1.txt >> 2.txt
   3: WRITELN cat 1.txt
   4: WRITELN cat 2.txt
   5: WRITELN ls
   6: WRITELN exit

mumsh $ mumsh $ mumsh $ 123
mumsh $ 123
mumsh $ 1.txt
2.txt
driver
mumsh
mumsh_memory_check
mumsh $ exit

mumsh $ mumsh $ mumsh $ 123
mumsh $ 123
mumsh $ 1.txt
2.txt
driver
mumsh
mumsh_memory_check
mumsh $ exit