///////////////////////////////////////////////////////////////
//                                                           //
// open.c     -  gets a stream definition from user          //
// ver 1.1                                                   //
//               definitions                                 //
//                                                           //
// Language:     Borland C, ver 3.0                          //
// Platform:     Gateway 386/25, win95.400                   //
// Application:  CSE784 demonstration                        //
// Author:       Jim Fawcett, 123 Link Hall, Syracuse Univ.  //
//                (315) 443-2654, jfawcett@cat.syr.edu       //
//                                                           //
///////////////////////////////////////////////////////////////

#include <stdlib.h>       /* free()    */
#include <string.h>       /* strcmp()  */
#include "lines.h"        /* getLine() */
#include "open.h"

/*----< open a stream for reading >----------------------------

  Inputs:
  - name of file to open - if null then user response from
    keyboard
  Outputs:
  - returns a FILE pointer to an open stream if file creation
    is successful, otherwise returns 0
*/

FILE *getRStream(char *name) {

  FILE *fptr;
  if(!name) {
    fprintf(stdout,"  please enter a filename for input: ");
    name = getLine(stdin);
    if(!(fptr=fopen(name,"r")))
      fprintf(stdout, "  can't open file %s\n", name);
    free(name);
    return fptr;
  }
  if(!strcmp(name,"stdin"))
    return stdin;
  if(!(fptr=fopen(name,"r")))
    fprintf(stdout, "  can't open file %s\n", name);
  return fptr;
}

/**/

/*----< open a stream for writing >----------------------------

  Inputs:
  - name of file to open - if null then user response from
    keyboard
  Outputs:
  - returns a FILE pointer to an open stream if file creation
    is successful, otherwise returns 0
*/

FILE *getWStream(char *name) {

  FILE *fptr;
  if(!name) {
    fprintf(stdout, "  please enter a filename for output: ");
    name = getLine(stdin);
    if(!(fptr=fopen(name,"w")))
      fprintf(stdout, "  can't open file %s\n", name);
    free(name);
    return fptr;
  }
  if(!strcmp(name,"stdout"))
    return stdout;
  if(!(fptr=fopen(name,"w")))
    fprintf(stdout, "  can't open file %s\n", name);
  return fptr;
}

/*----< test stub >------------------------------------------*/

#ifdef TEST_OPEN

void main() {

  FILE   *in = getRStream(0);
  FILE  *out = getWStream(0);
  char *line = getLine(in);

  if(in && out) {
    fprintf(stdout,"\n\n  Testing open module\n ====================\n");
    fprintf(out, "%s\n", line);
    fprintf(stdout, "  just wrote\n  \"%s\"\n  to output file\n", line);
  }
  fprintf(stdout,"\n");
}

#endif