quickly obtain the call stack of a running ruby process

ruby_stack_dump

#!/bin/sh -e
process=$1
commands=`mktemp -t gdb.XXXXXXXXXX`
cat > $commands << '_EOF_'
if during_gc == 1
  x/s "cannot backtrace during gc"
else
  set $stack = (VALUE)backtrace(-1)
  set $count = (int)rb_fix2int(rb_ary_length($stack))
  set $index = 0
  while $index < $count
    set $frame = (VALUE)rb_ary_entry($stack, $index)
    x/s ((struct RString*)$frame)->ptr
    set $index = $index + 1
  end
end
detach
_EOF_
gdb --batch --pid=$process -x $commands 2>&1 | grep 0x
rm -f $commands