/*************************************************************************\
* Copyright (c) 2002 The University of Chicago, as Operator of Argonne
* National Laboratory.
* Copyright (c) 2002 The Regents of the University of California, as
* Operator of Los Alamos National Laboratory.
* This file is distributed subject to a Software License Agreement found
* in the file LICENSE that is included with this distribution. 
\*************************************************************************/

/*
 $Log: rpn_csh.c,v $
 Revision 1.13  2003/09/02 17:59:33  soliday
 Cleaned up code for Linux.

 Revision 1.12  2003/08/28 20:49:11  soliday
 Cleaned up the code.

 Revision 1.11  2002/08/14 16:28:59  soliday
 Added Open License

 Revision 1.10  2000/04/13 16:21:51  soliday
 Moved some WIN32 stuff to mdb.h

 Revision 1.9  2000/03/27 20:29:03  borland
 Added rpn_execn() and rpn_execs() functions and user functions execn and
 execs.  These execute commands from the string stack.  Results are put
 on the numerical or string stack.

 Revision 1.8  1999/12/21 17:52:24  soliday
 vxWorks does not support popen and getpid

 Revision 1.7  1999/12/15 19:00:29  soliday
 Added support for vxWorks.

 Revision 1.6  1999/07/08 22:26:59  soliday
 Added include statement for ctype.h, process.h, and unistd.h
 Also defined popen on WIN32 and created a dummy sigpause function for WIN32.

 Revision 1.5  1999/06/01 14:39:10  soliday
 Removed warnings when compiled under Linux.

 Revision 1.4  1999/05/04 14:47:46  borland
 Added conditional compilation statement to get it to compile under WIN32.
 Won't work properly, but then it probably won't be used on WIN32 either.

 Revision 1.3  1998/08/11 18:27:56  borland
 New version per R. Soliday with true pcoding of UDFs for 4-8 x faster
 evaluation.

 * Revision 1.2  1995/09/05  21:22:26  saunders
 * First test release of the SDDS1.5 package.
 *
*/

/* file: rpn_csh.
 * purpose: create and manage a synchronize csh subprocess
 *
 * M. Borland, 1993
 */
#include "rpn_internal.h"
#include <signal.h>
#include <ctype.h>
#if defined(_WIN32)
#include <process.h>
#else
#include <unistd.h>
#endif

#if defined(_WIN32) && !defined(__BORLANDC__)
#define SIGUSR1 16
#endif

/* this gets the code to compile, but the code won't work! */
#if defined(_WIN32) || defined(vxWorks)
void sigpause(int x);

void sigpause(x) 
{
  }
#endif

static FILE *fp = NULL;
static int pid;

void rpn_csh()
{
    char *ptr;
    void dummy_sigusr1();
    static char s[1024];

    signal(SIGUSR1, dummy_sigusr1);

    if (!fp) {
        /* open a pipe and start csh */
#if defined(vxWorks)
      fprintf(stderr, "popen is not supported in vxWorks\n");
      exit(1);
#else
      fp = popen("csh", "w");
      pid = getpid();
#endif
    }

    /* loop to print prompt and accept commands */
    while (fputs("csh> ", stdout), fgets(s, 100, stdin)) {
        /* send user's command along with another than causes subprocess
         * to send the SIGUSR1 signal this process 
         */
        ptr = s;
        while (isspace(*ptr))
            ptr++;
        if (strncmp(ptr, "quit", 4)==0 || strncmp(ptr, "exit", 4)==0)
            break;
        fprintf(fp, "%s\nkill -USR1 %d\n", s, pid);
        fflush(fp);
        /* pause until SIGUSR1 is received */
        sigpause(SIGUSR1);
        }

    /* back to default behavior for sigusr1 */
    signal(SIGUSR1, SIG_DFL);
    }

void rpn_csh_str()
{
    char *string;
    void dummy_sigusr1();
    signal(SIGUSR1, dummy_sigusr1);

    if (!fp) {
        /* open a pipe and start csh */
#if defined(vxWorks)
      fprintf(stderr, "popen is not supported in vxWorks\n");
      exit(1);
#else
      fp = popen("csh", "w");
      pid = getpid();
#endif
    }
    if (!(string = pop_string()))
        return;

    fprintf(fp, "%s\nkill -USR1 %d\n", string, pid);
    fflush(fp);
    /* pause until SIGUSR1 is received */
    sigpause(SIGUSR1);

    /* back to default behavior for sigusr1 */
    signal(SIGUSR1, SIG_DFL);
    }

/* dummy signal handler for use with sigpause */
void dummy_sigusr1()
{
    }

void rpn_execs()
{
    char *string;
#if !defined(vxWorks)
    char buffer[1024];
    FILE *fp;
#endif

    if (!(string = pop_string()))
        return;

#if defined(vxWorks)
    fprintf(stderr, "popen is not supported in vxWorks\n");
    exit(1);
#else
    if (!(fp = popen(string, "r"))) {
      fprintf(stderr, "error: invalid command: %s\n", string);
      stop();
      return;
    }
    if (feof(fp)) {
      fprintf(stderr, "error: command %s returns EOF\n", string);
      stop();
      return;
    }
    if (!fgets(buffer, 1024, fp)) {
      fprintf(stderr, "error: command %s returns NULL\n", string);
      stop();
      return;
    }
    do {
      chop_nl(buffer);
      push_string(buffer);
    } while (fgets(buffer, 1024, fp));
#endif

  }

void rpn_execn()
{
#if !defined(vxWorks)
    char *ptr;
    char buffer[1024];
    FILE *fp;
    double value;
#endif
    char *string;

    if (!(string = pop_string()))
        return;

#if defined(vxWorks)
    fprintf(stderr, "popen is not supported in vxWorks\n");
    exit(1);
#else
    if (!(fp = popen(string, "r"))) {
      fprintf(stderr, "error: invalid command: %s\n", string);
      stop();
      return;
    }
    if (feof(fp)) {
      fprintf(stderr, "error: command %s returns EOF\n", string);
      stop();
      return;
    }
    if (fgets(buffer, 1024, fp) == NULL) {
      fprintf(stderr, "error: command %s returns NULL\n", string);
      stop();
      return;
    }
    do {
      while ((ptr=get_token(buffer))) {
        if (sscanf(ptr, "%le", &value)==1)
          push_num(value);
        else
          push_string(ptr);
      }
    } while (fgets(buffer, 1024, fp));
#endif

  }