fgetl hangs reading serial port

To: bug-octave@xxxxxxxxxxxxxxxxx
Cc: bmadigan
Subject: fgetl hangs reading serial port
--------
Bug report for Octave 2.1.40 configured for i386-redhat-linux-gnu

Description:
-----------
I cannot read data from a serial device from within octave.  I establish
communication with the device using minicom and am able to send and
receive.  I exit minicom (with minicom configured to do nothing to the
port when it exits) and run the following program:

[fid,msg]=fopen("/dev/ttyS0","r+","native")
cmdstr=setstr([0x41,0x54,0x0d,0x00])
fputs(fid,cmdstr)
sleep(1);
fgetl(fid)
fclose(fid)

The program hangs at fgetl.  I have used the procedure on two different
computers and talked to two different devices.  (The example above is
talking to a modem, sending "AT" and expecting "OK").  I am sure the
command string (cmdstr) is reaching the serial device because I can see
a change of status on the serial device ( for example the send data and
reveive data lights on the modem blink).

I have also tried begining the program with 

system(setserial .....) 

to configure the serial port with the same results.

Repeat-By:
---------

Experiencing identical behavior on two different computers and serial
devices.

Fix:
---

Potentially...writing c functions that implement serial port opening,
closing, reading and writing and wraping them with a new octave
interface (ie mkoctfile myfilerotuines.c)


Configuration (please do not edit this section):
-----------------------------------------------

uname output:     Linux weld1.mtech.edu 2.4.24 #1 Tue May 4 15:14:19 MDT
2004 i686 i686 i386 GNU/Linux
configure opts:   '--host=i386-redhat-linux' '--build=i386-redhat-linux'
'--target=i386-redhat-linux-gnu' '--program-prefix=' '--prefix=/usr'
'--exec-prefix=/usr' '--bindir=/usr/bin' '--sbindir=/usr/sbin'
'--sysconfdir=/etc' '--datadir=/usr/share' '--includedir=/usr/include'
'--libdir=/usr/lib' '--libexecdir=/usr/libexec' '--localstatedir=/var'
'--sharedstatedir=/usr/com' '--mandir=/usr/share/man'
'--infodir=/usr/share/info' '--enable-dl' '--enable-shared=yes'
'--enable-rpath' '--enable-lite-kernel' '--enable-picky-flags'
'--enable-static=no' 'CFLAGS=-O2 -march=i386 -mcpu=i686 -g'
'CXXFLAGS=-O2 -march=i386 -mcpu=i686 -g' 'FFLAGS=-O2 -march=i386
-mcpu=i686 -g' 'build_alias=i386-redhat-linux'
'host_alias=i386-redhat-linux' 'target_alias=i386-redhat-linux-gnu'
Fortran compiler: g77
FFLAGS:           -O2 -march=i386 -mcpu=i686 -g
F2C:              
F2CFLAGS:         
FLIBS:            -L/usr/lib/gcc-lib/i386-redhat-linux/3.2.1
-L/usr/lib/gcc-lib/i386-redhat-linux/3.2.1/../../.. -lfrtbegin -lg2c -lm
-lgcc_s
CPPFLAGS:         
INCFLAGS:         -I. -I. -I./liboctave -I./src -I./libcruft/misc 
-I./glob -I./glob
C compiler:       i386-redhat-linux-gcc, version 3.2.1 20030202 (Red Hat
Linux 8.0 3.2.1-7)
CFLAGS:           -O2 -march=i386 -mcpu=i686 -g
CPICFLAG:         -fPIC
C++ compiler:     i386-redhat-linux-g++, version 3.2.1 20030202 (Red Hat
Linux 8.0 3.2.1-7)
CXXFLAGS:         -O2 -march=i386 -mcpu=i686 -g
CXXPICFLAG:       -fPIC
LD_CXX:           i386-redhat-linux-g++
LDFLAGS:          
LIBFLAGS:         -L.
RLD_FLAG:         -Xlinker -rpath -Xlinker /usr/lib/octave-2.1.40
BLAS_LIBS:        -llapack -lblas
FFTW_LIBS:        
LIBS:             -lreadline  -lncurses -ldl -lm 
LEXLIB:           
LIBPLPLOT:        
LIBDLFCN:         
LIBGLOB:          ./glob/glob.o ./glob/fnmatch.o
SED:              /bin/sed
DEFS:

  -DPACKAGE_NAME="" -DPACKAGE_TARNAME="" -DPACKAGE_VERSION=""
  -DPACKAGE_STRING="" -DPACKAGE_BUGREPORT="" -DOCTAVE_SOURCE=1
  -DSTDC_HEADERS=1 -DHAVE_SYS_TYPES_H=1 -DHAVE_SYS_STAT_H=1
  -DHAVE_STDLIB_H=1 -DHAVE_STRING_H=1 -DHAVE_MEMORY_H=1
-DHAVE_STRINGS_H=1
  -DHAVE_INTTYPES_H=1 -DHAVE_STDINT_H=1 -DHAVE_UNISTD_H=1 -DSEPCHAR=1
  -DSEPCHAR_STR=":" -D__NO_MATH_INLINES=1
-DCXX_NEW_FRIEND_TEMPLATE_DECL=1
  -DCXX_ISO_COMPLIANT_LIBRARY=1 -DCXX_ABI=unknown -DHAVE_LIBM=1
  -DF77_FUNC(name,NAME)=name ## _ -DF77_FUNC_(name,NAME)=name ## __
  -DHAVE_BLAS=1 -DHAVE_GETHOSTNAME=1 -DHAVE_GETPWNAM=1 -DSIZEOF_SHORT=2
  -DSIZEOF_INT=4 -DSIZEOF_LONG=4 -DSIZEOF_LONG_LONG=8 -DHAVE_ALLOCA_H=1
  -DHAVE_ALLOCA=1 -DNPOS=std::string::npos -DSTDC_HEADERS=1
  -DHAVE_DIRENT_H=1 -DTIME_WITH_SYS_TIME=1 -DHAVE_SYS_WAIT_H=1
  -DHAVE_ASSERT_H=1 -DHAVE_CURSES_H=1 -DHAVE_DLFCN_H=1 -DHAVE_FCNTL_H=1
  -DHAVE_FLOAT_H=1 -DHAVE_GRP_H=1 -DHAVE_LIMITS_H=1 -DHAVE_MEMORY_H=1
  -DHAVE_NCURSES_H=1 -DHAVE_POLL_H=1 -DHAVE_PWD_H=1 -DHAVE_STDLIB_H=1
  -DHAVE_STRING_H=1 -DHAVE_SYS_IOCTL_H=1 -DHAVE_SYS_PARAM_H=1
  -DHAVE_SYS_POLL_H=1 -DHAVE_SYS_RESOURCE_H=1 -DHAVE_SYS_SELECT_H=1
  -DHAVE_SYS_STAT_H=1 -DHAVE_SYS_TIME_H=1 -DHAVE_SYS_TIMES_H=1
  -DHAVE_SYS_TYPES_H=1 -DHAVE_SYS_UTSNAME_H=1 -DHAVE_TERMCAP_H=1
  -DHAVE_UNISTD_H=1 -DHAVE_VARARGS_H=1 -DHAVE_SSTREAM=1
-DHAVE_TERMIO_H=1
  -DHAVE_SGTTY_H=1 -DHAVE_GLOB_H=1 -DHAVE_FNMATCH_H=1 -DHAVE_ATEXIT=1
  -DHAVE_BCOPY=1 -DHAVE_BZERO=1 -DHAVE_DUP2=1 -DHAVE_ENDGRENT=1
  -DHAVE_ENDPWENT=1 -DHAVE_EXECVP=1 -DHAVE_FCNTL=1 -DHAVE_FORK=1
  -DHAVE_GETCWD=1 -DHAVE_GETEGID=1 -DHAVE_GETEUID=1 -DHAVE_GETGID=1
  -DHAVE_GETGRENT=1 -DHAVE_GETGRGID=1 -DHAVE_GETGRNAM=1 -DHAVE_GETPGRP=1
  -DHAVE_GETPID=1 -DHAVE_GETPPID=1 -DHAVE_GETPWENT=1 -DHAVE_GETPWUID=1
  -DHAVE_GETTIMEOFDAY=1 -DHAVE_GETUID=1 -DHAVE_GETWD=1 -DHAVE_KILL=1
  -DHAVE_LINK=1 -DHAVE_LOCALTIME_R=1 -DHAVE_LSTAT=1 -DHAVE_MEMMOVE=1
  -DHAVE_MKDIR=1 -DHAVE_MKFIFO=1 -DHAVE_ON_EXIT=1 -DHAVE_PIPE=1
  -DHAVE_POLL=1 -DHAVE_PUTENV=1 -DHAVE_RAISE=1 -DHAVE_READLINK=1
  -DHAVE_RENAME=1 -DHAVE_RINDEX=1 -DHAVE_RMDIR=1 -DHAVE_SELECT=1
  -DHAVE_SETGRENT=1 -DHAVE_SETPWENT=1 -DHAVE_SETVBUF=1
-DHAVE_SIGACTION=1
  -DHAVE_SIGLONGJMP=1 -DHAVE_SIGPENDING=1 -DHAVE_SIGPROCMASK=1
  -DHAVE_SIGSUSPEND=1 -DHAVE_STAT=1 -DHAVE_STRCASECMP=1 -DHAVE_STRDUP=1
  -DHAVE_STRERROR=1 -DHAVE_STRFTIME=1 -DHAVE_STRNCASECMP=1
  -DHAVE_STRPTIME=1 -DHAVE_SYMLINK=1 -DHAVE_TEMPNAM=1 -DHAVE_UMASK=1
  -DHAVE_UNLINK=1 -DHAVE_USLEEP=1 -DHAVE_VFPRINTF=1 -DHAVE_VSPRINTF=1
  -DHAVE_VSNPRINTF=1 -DHAVE_WAITPID=1 -DHAVE_LIBDL=1 -DHAVE_DLOPEN=1
  -DHAVE_DLSYM=1 -DHAVE_DLERROR=1 -DHAVE_DLCLOSE=1 -DHAVE_DLOPEN_API=1
  -DENABLE_DYNAMIC_LINKING=1 -DHAVE_TIMEVAL=1 -DHAVE_FINITE=1
-DHAVE_ISNAN=1
  -DHAVE_ISINF=1 -DHAVE_ACOSH=1 -DHAVE_ASINH=1 -DHAVE_ATANH=1
  -DHAVE_ERF=1 -DHAVE_ERFC=1 -DHAVE_STRUCT_STAT_ST_BLKSIZE=1
  -DHAVE_STRUCT_STAT_ST_BLOCKS=1 -DHAVE_STRUCT_STAT_ST_RDEV=1
  -DHAVE_STRUCT_TM_TM_ZONE=1 -DHAVE_TM_ZONE=1 -DUSE_READLINE=1
  -DEXCEPTION_IN_MATH=1 -DRETSIGTYPE=void -DSYS_SIGLIST_DECLARED=1
  -DHAVE_SYS_SIGLIST=1 -DHAVE_POSIX_SIGNALS=1 -DHAVE_DEV_T=1
  -DHAVE_INO_T=1 -DHAVE_NLINK_T=1 -DHAVE_NLINK_T=1 -DHAVE_SIGSET_T=1
  -DHAVE_SIG_ATOMIC_T=1 -DHAVE_GETRUSAGE=1 -DHAVE_TIMES=1
  -DYYTEXT_POINTER=1 -DGNUPLOT_BINARY="gnuplot"
-DGNUPLOT_HAS_MULTIPLOT=1
  -DGNUPLOT_HAS_FRAMES=1

User-preferences (please do not edit this section):
--------------------------------------------------

  EDITOR = "emacs"
  EXEC_PATH =
":/usr/local/bin:/usr/bin:/bin:/usr/X11R6/bin:/sbin:/usr/sbin:/home/bmadigan/bin:/sbin:/sbin:/usr/sbin"
  IMAGEPATH = ".:/usr/share/octave/2.1.40/imagelib//"
  INFO_FILE = "/usr/share/info/octave.info"
  INFO_PROGRAM = "info"
  LOADPATH = ":"
  PAGER = "less -e -P'-- less ?pB(%pB\\%):--. (f)orward, (b)ack,
(q)uit$'"
  PS1 = "\\s:\\#> "
  PS2 = "> "
  PS4 = "+ "
  automatic_replot = 0
  beep_on_error = 0
  completion_append_char = " "
  default_eval_print_flag = 1
# default_global_variable_value = <no value or error in displaying it>
  default_return_value = []
  default_save_format = "ascii"
  define_all_return_values = 0
  do_fortran_indexing = 0
  echo_executing_commands = 0
  empty_list_elements_ok = 1
  fixed_point_format = 0
  gnuplot_binary = "gnuplot"
  gnuplot_command_end = "\n"
  gnuplot_command_plot = "pl"
  gnuplot_command_replot = "rep"
  gnuplot_command_splot = "sp"
  gnuplot_command_title = "t"
  gnuplot_command_using = "u"
  gnuplot_command_with = "w"
  gnuplot_has_frames = 1
  gnuplot_has_multiplot = 1
  history_file = "/home/bmadigan/.octave_hist"
  history_size = 1024
  ignore_function_time_stamp = "system"
  implicit_num_to_str_ok = 0
  implicit_str_to_num_ok = 0
  initialize_global_variables = 0
  max_recursion_depth = 256
  ok_to_lose_imaginary_part = "warn"
  output_max_field_width = 10
  output_precision = 5
  page_output_immediately = 0
  page_screen_output = 1
  prefer_column_vectors = 1
  print_answer_id_name = 1
  print_empty_dimensions = 1
  print_rhs_assign_val = 0
  propagate_empty_matrices = 1
  resize_on_range_error = 1
  return_last_computed_value = 0
  save_precision = 15
  saving_history = 1
  silent_functions = 0
  split_long_rows = 1
  string_fill_char = " "
  struct_levels_to_print = 2
  suppress_verbose_help_message = 0
  treat_neg_dim_as_zero = 0
  warn_assign_as_truth_value = 1
  warn_divide_by_zero = 1
  warn_function_name_clash = 1
  warn_future_time_stamp = 1
  warn_missing_semicolon = 0
  warn_variable_switch_label = 0
  whitespace_in_literal_matrix = 



-------------------------------------------------------------
Octave is freely available under the terms of the GNU GPL.

Octave's home on the web:  http://www.octave.org
How to fund new projects:  http://www.octave.org/funding.html
Subscription information:  http://www.octave.org/archive.html
-------------------------------------------------------------