Log: ~/vis/test:$ gsi test.scm "~\"GNU gdb 6.8-debian\\n\"" "~\"Copyright (C) 2008 Free Software Foundation, Inc.\\n\"" "~\"License GPLv3+: GNU GPL version 3 or later < http://gnu.org/licenses/gpl.html>\\n\"" "~\"This is free software: you are free to change and redistribute it.\\n\"" "~\"There is NO WARRANTY, to the extent permitted by law. Type \\\"show copying\\\"\\n\"" "~\"and \\\"show warranty\\\" for details.\\n\"" "~\"This GDB was configured as \\\"x86_64-linux-gnu\\\".\\n\"" "(gdb) " ~/vis/test:$ gsi test.scm ~/vis/test:$ gsi test.scm ~/vis/test:$ gsi test.scm "~\"GNU gdb 6.8-debian\\n\"" "~\"Copyright (C) 2008 Free Software Foundation, Inc.\\n\"" "~\"License GPLv3+: GNU GPL version 3 or later < http://gnu.org/licenses/gpl.html>\\n\"" "~\"This is free software: you are free to change and redistribute it.\\n\"" "~\"There is NO WARRANTY, to the extent permitted by law. Type \\\"show copying\\\"\\n\"" "~\"and \\\"show warranty\\\" for details.\\n\"" "~\"This GDB was configured as \\\"x86_64-linux-gnu\\\".\\n\"" "(gdb) " ~/vis/test:$ gsi test.scm "~\"GNU gdb 6.8-debian\\n\"" "~\"Copyright (C) 2008 Free Software Foundation, Inc.\\n\"" "~\"License GPLv3+: GNU GPL version 3 or later < http://gnu.org/licenses/gpl.html>\\n\"" "~\"This is free software: you are free to change and redistribute it.\\n\"" "~\"There is NO WARRANTY, to the extent permitted by law. Type \\\"show copying\\\"\\n\"" "~\"and \\\"show warranty\\\" for details.\\n\"" "~\"This GDB was configured as \\\"x86_64-linux-gnu\\\".\\n\"" "(gdb) " ~/vis/test:$ gsi test.scm ~/vis/test:$ Code: ~/vis/test:$ cat test.scm (define p (open-process (list path: "gdb" arguments: '("--interpreter=mi2")))) (define (rr) (if (char-ready? p) (pp (read-line p)))) (rr) (rr) (rr) (rr) (rr) (rr) (rr) (rr) (rr) (rr) (rr) (rr) (rr) (rr) (rr) (rr) (rr) (rr) (rr) (rr) Questions: 1) Why is this non-deterministic? (subject to how fast gdb prints out its data?) 2) How can I make it deterministic? (I'd prefer something better than "sleep for 0.5 seconds") Thanks!