octave:1> plot(1:200)
Xlib:  extension "NV-GLX" missing on display ":1175.0".
octave:2> print tes01.pdf
Detaching after fork from child process 32745.
^C
Program received signal SIGINT, Interrupt.
0x00000032264d4180 in __read_nocancel () at ../sysdeps/unix/syscall-template.S:82
82T_PSEUDO (SYSCALL_SYMBOL, SYSCALL_NAME, SYSCALL_NARGS)
(gdb) bt
#0  0x00000032264d4180 in __read_nocancel () at ../sysdeps/unix/syscall-template.S:82
#1  0x0000003226471518 in _IO_new_file_underflow (fp=0x1056b10) at fileops.c:598
#2  0x000000322647301e in _IO_default_uflow (fp=0x1056b10) at genops.c:440
#3  0x000000322646e53b in _IO_getc (fp=0x1056b10) at getc.c:41
#4  0x00007ffff738304c in c_file_ptr_buf::underflow_common (this=0x1056608, bump=true)
    at c-file-ptr-stream.cc:72
#5  0x000000323087a879 in std::basic_istream<char, std::char_traits<char> >::get(char&) ()
   from /usr/lib64/libstdc++.so.6
#6  0x00007ffff76380fb in run_command_and_return_output (args=<value optimized out>,
    nargout=<value optimized out>) at toplev.cc:794
#7  Fsystem (args=<value optimized out>, nargout=<value optimized out>) at toplev.cc:955
#8  0x00007ffff769b1c1 in octave_builtin::do_multi_index_op (this=0x7642e8, nargout=2, args=...,
    lvalue_list=<value optimized out>) at ov-builtin.cc:129
#9  0x00007ffff769a1fc in octave_builtin::subsref (this=0x7642e8, type="(", idx=std::list = {...},
    nargout=2, lvalue_list=<value optimized out>) at ov-builtin.cc:64
#10 0x00007ffff776d756 in octave_value::subsref (this=<value optimized out>, type=<value optimized out>,
    idx=<value optimized out>, nargout=<value optimized out>, lvalue_list=<value optimized out>)
    at ov.cc:1211
#11 0x00007ffff780701a in tree_index_expression::rvalue (this=<value optimized out>, nargout=2, lvalue_list=
    0x7fffffffa960) at pt-idx.cc:408
#12 0x00007ffff77ea7a5 in tree_multi_assignment::rvalue (this=0x10702f0) at pt-assign.cc:365
#13 0x00007ffff77ea32e in tree_multi_assignment::rvalue1 (this=0x10702f0, nargout=0) at pt-assign.cc:320
#14 0x00007ffff77f9573 in tree_evaluator::visit_statement (this=<value optimized out>,
    stmt=<value optimized out>) at pt-eval.cc:729
#15 0x00007ffff77f81b8 in tree_evaluator::visit_statement_list (this=0x7ffff7ffb9f8, lst=...)
    at pt-eval.cc:765
#16 0x00007ffff7760242 in octave_user_function::do_multi_index_op (this=0x6a9fe8, nargout=2,
    args=<value optimized out>, lvalue_list=0x7fffffffb450) at ov-usr-fcn.cc:450
#17 0x00007ffff775f379 in octave_user_function::subsref (this=0x6a9fe8, type="(", idx=std::list = {...},
    nargout=2, lvalue_list=<value optimized out>) at ov-usr-fcn.cc:303
#18 0x00007ffff776d756 in octave_value::subsref (this=<value optimized out>, type=<value optimized out>,
    idx=<value optimized out>, nargout=<value optimized out>, lvalue_list=<value optimized out>)
    at ov.cc:1211
#19 0x00007ffff780701a in tree_index_expression::rvalue (this=<value optimized out>, nargout=2,
    lvalue_list=0x7fffffffb450) at pt-idx.cc:408
#20 0x00007ffff77ea7a5 in tree_multi_assignment::rvalue (this=0x104a490) at pt-assign.cc:365
#21 0x00007ffff77ea32e in tree_multi_assignment::rvalue1 (this=0x104a490, nargout=0) at pt-assign.cc:320
#22 0x00007ffff77f9573 in tree_evaluator::visit_statement (this=<value optimized out>,
    stmt=<value optimized out>) at pt-eval.cc:729
#23 0x00007ffff77f81b8 in tree_evaluator::visit_statement_list (this=0x7ffff7ffb9f8, lst=...)
    at pt-eval.cc:765
#24 0x00007ffff77f93ac in tree_evaluator::visit_switch_command (this=0x7ffff7ffb9f8,
    cmd=<value optimized out>) at pt-eval.cc:847
#25 0x00007ffff77f94d2 in tree_evaluator::visit_statement (this=0x7ffff7ffb9f8, stmt=<value optimized out>)
    at pt-eval.cc:700
#26 0x00007ffff77f81b8 in tree_evaluator::visit_statement_list (this=0x7ffff7ffb9f8, lst=...)
    at pt-eval.cc:765
#27 0x00007ffff7760242 in octave_user_function::do_multi_index_op (this=0x6a9f40, nargout=1,
    args=<value optimized out>, lvalue_list=0x0) at ov-usr-fcn.cc:450
#28 0x00007ffff775b9a0 in octave_user_function::do_multi_index_op (this=<value optimized out>,
    nargout=<value optimized out>, args=<value optimized out>) at ov-usr-fcn.cc:333
#29 0x00007ffff7761431 in octave_value::do_multi_index_op (this=<value optimized out>,
    nargout=<value optimized out>, idx=<value optimized out>) at ov.cc:1267
---Type <return> to continue, or q <return> to quit---
#30 0x00007ffff756bf6a in feval (name="__fltk_print__", args=..., nargout=1) at oct-parse.yy:4116
#31 0x00007ffff756cab1 in feval (args=<value optimized out>, nargout=1) at oct-parse.yy:4170
#32 0x00007ffff756cbec in Ffeval (args=..., nargout=1) at oct-parse.yy:4213
#33 0x00007ffff769b1c1 in octave_builtin::do_multi_index_op (this=0x762b80, nargout=1, args=...,
    lvalue_list=<value optimized out>) at ov-builtin.cc:129
#34 0x00007ffff769a1fc in octave_builtin::subsref (this=0x762b80, type="(", idx=std::list = {...},
    nargout=1, lvalue_list=<value optimized out>) at ov-builtin.cc:64
#35 0x00007ffff769af6c in octave_builtin::subsref (this=<value optimized out>, type=<value optimized out>,
    idx=<value optimized out>, nargout=<value optimized out>) at ov-builtin.cc:47
#36 0x00007ffff769c1c1 in octave_builtin::subsref(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::list<octave_value_list, std::allocator<octave_value_list> > const&) ()
   from /d/src/octave/hg/octave/src/.libs/liboctinterp-3.3.52+.so
#37 0x00007ffff776d715 in octave_va
    idx=<value optimized out>, nargout=<value optimized out>) at ov.cc:1200
#38 0x00007ffff776d765 in octave_value::subsref (this=<value optimized out>, type=<value optimized out>,
    idx=<value optimized out>, nargout=<value optimized out>, lvalue_list=<value optimized out>)
    at ov.cc:1213
#39 0x00007ffff780701a in tree_index_expression::rvalue (this=<value optimized out>, nargout=1,
    lvalue_list=0x0) at pt-idx.cc:408
#40 0x00007ffff78077ab in tree_index_expression::rvalue (this=<value optimized out>,
    nargout=<value optimized out>) at pt-idx.cc:278
#41 0x00007ffff7806157 in tree_index_expression::rvalue1 (this=0xf287e0, nargout=1) at pt-idx.cc:419
#42 0x00007ffff77e9ed9 in tree_simple_assignment::rvalue1 (this=0xf29c40) at pt-assign.cc:206
#43 0x00007ffff77f9573 in tree_evaluator::visit_statement (this=<value optimized out>,
    stmt=<value optimized out>) at pt-eval.cc:729
#44 0x00007ffff77f81b8 in tree_evaluator::visit_statement_list (this=0x7ffff7ffb9f8, lst=...)
    at pt-eval.cc:765
#45 0x00007ffff77f7e16 in tree_evaluator::visit_unwind_protect_command (this=0x7ffff7ffb9f8,
    cmd=<value optimized out>) at pt-eval.cc:996
#46 0x00007ffff77f94d2 in tree_evaluator::visit_statement (this=0x7ffff7ffb9f8, stmt=<value optimized out>)
    at pt-eval.cc:700
#47 0x00007ffff77f81b8 in tree_evaluator::visit_statement_list (this=0x7ffff7ffb9f8, lst=...)
    at pt-eval.cc:765
#48 0x00007ffff7760242 in octave_us
    args=<value optimized out>, lvalue_list=0x0) at ov-usr-fcn.cc:450
#49 0x00007ffff775f379 in octave_user_function::subsref (this=0x6a9178, type="(", idx=std::list = {...},
    nargout=0, lvalue_list=<value optimized out>) at ov-usr-fcn.cc:303
#50 0x00007ffff775f89c in octave_user_function::subsref (this=<value optimized out>,
    type=<value optimized out>, idx=<value optimized out>, nargout=<value optimized out>)
    at ov-usr-fcn.cc:286
#51 0x00007ffff776d6f1 in octave_value::subsref (this=<value optimized out>, type=<value optimized out>,
    idx=<value optimized out>, nargout=<value optimized out>) at ov.cc:1202
#52 0x00007ffff776d765 in octave_value::subsref (this=<value optimized out>, type=<value optimized out>,
    idx=<value optimized out>, nargout=<value optimized out>, lvalue_list=<value optimized out>)
    at ov.cc:1213
#53 0x00007ffff780701a in tree_index_expression::rvalue (this=<value optimized out>, nargout=0,
    lvalue_list=0x0) at pt-idx.cc:408
#54 0x00007ffff78077ab in tree_index_expression::rvalue (this=<value optimized out>,
    nargout=<value optimized out>) at pt-idx.cc:278
#55 0x00007ffff7806157 in tree_index_expression::rvalue1 (this=0x8cf910, nargout=0) at pt-idx.cc:419
#56 0x00007ffff77f9573 in tree_evaluator::visit_statement (this=<value optimized out>,
    stmt=<value optimized out>) at pt-eval.cc:729
#57 0x00007ffff77f81b8 in tree_evaluator::visit_statement_list (this=0x7ffff7ffb9f8, lst=...)
---Type <return> to continue, or q <return> to quit---
    at pt-eval.cc:765
#58 0x00007ffff7635db4 in main_loop () at toplev.cc:570
#59 0x00007ffff75e7aeb in octave_main (argc=<value optimized out>, argv=0x7fffffffd2f8, embedded=0)
    at octave.cc:882
#60 0x000000322641ec5d in __libc_start_main (main=0x400840 <main>, argc=6, ubp_av=0x7fffffffd2f8,
    init=<value optimized out>, fini=<value optimized out>, rtld_fini=<value optimized out>,
    stack_end=0x7fffffffd2e8) at libc-start.c:226
#61 0x0000000000400779 in _start ()
(gdb)