/**
   tdslib.c
   k.furukawa, mar.19.2003.

   k.f, mar.20.2003.  check return value
   k.f, mar.30.2003.  use strlen instead of sizeof
   k.f, mar.30.2003.  shorter timeout (this did not work)
   k.f, mar.30.2003.  intercept signal to clean up communication
   k.f, apr.5.2003.   separate library routines (tdstest4 v1.6)
   k.f, apr.6.2003.   allocate structure locally (v1.6.1)
   k.f, apr.7.2003.   return string (v1.6.2)
   k.f, apr.10.2003.  library for tcltds (tdslib v1.7)
   k.f, apr.11.2003.  use tcltds.h (tdslib v1.7.1)
   k.f, sep.5.2003.   use clnt_control(timeout), device_lock/unlock (v1.8)
   k.f, sep.6.2003.   check magic, add tds_timeout
   k.f, dec.10.2003.  remove device_abort from tds_open (v1.8.5)
   k.f, sep.3.2007.   ignore error at device_async for dso5054a (v1.9.0)
   k.f, sep.4.2007.   'gpib0' for tektronix, 'inst0' for agilent (v1.9.1)
   k.f, dec.9.2007.   larger buffer size (v1.9.2)
   k.f, aug.27.2008.  made 'inst0' the default (v2.0)

**/

/**
  This file defines 3 local functions and 7 global functions

   Local functions:
   tds_malloc  --  wrapper for malloc
   tds_free  --  wrapper for free
   tds_signalhandle  --  possible signal handler (does not work ?)

   Global functions:
   int tds_init( tds_struct **to_st, char *to_devip )
     --  initialize local rpc data structures
   int tds_open( tds_struct *to_st )
     --  open rpc connection to a tds device
   int tds_timeout( tds_struct *to_st, int millisec )
     --  specify processing time-out in milli-seconds
   int tds_write( tds_struct *to_st, char *to_writestring )
     --  write to a tds device
   int tds_read( tds_struct *to_st, char *to_print )
     --  read from a tds device
   int tds_lock( tds_struct *to_st )
     --  lock a tds device
   int tds_unlock( tds_struct *to_st )
     --  unlock a tds device
   int tds_close( tds_struct *to_st )
     --  close rpc connection

  This library works at least with following devices.
     Tektronix TDS3xxxB
     Tektronix DPO3xxx
     Tektronix DPO4xxx
     Tektronix DPO7xxx
     Tektronix DSA8xxx
     Agilent   DSO5xxx
**/

/**
 *  int tds_init( tds_struct **to_st, char *to_devip )
 *    --  initialize local rpc data structures
**/

/**
 *  int tds_open( tds_struct *to_st )
 *    --  open rpc connection to a tds device
**/

/**
 *  int tds_timeout( tds_struct *to_st, int millisec )
 *    --  specify timeout in milli-seconds
**/

/**
 *  int tds_write( tds_struct *to_st, char *to_writestring )
 *    --  write to a tds device
**/

/**
 *  int tds_read( tds_struct *to_st, char *to_print )
 *    --  read from a tds device
**/

/**
 *  int tds_lock( tds_struct *to_st )
 *    --  lock a tds device
**/

/**
 *  int tds_unlock( tds_struct *to_st )
 *    --  unlock a tds device
**/

/**
 *  int tds_close( tds_struct *to_st )
 *    --  close rpc connection
**/

/**
  Sample main routine

   Shell command usage:
      tdstest -- please specify arguments
      usage: tdstest {ip} {command} [{debug}]
      ex.:   tdstest 172.19.68.21 '*idn?'
      ex.:   tdstest 172.19.68.21 '*idn?' debug

**/

Other examples are;

tdstest osc1 \
 'ch1:pos?;vol?;:dat:sou ch1;enc asci;star 16400;stop 66600;:curve?' > d1.dat

tdstest 172.19.73.170 'FETCH?' inst0