spawnvp still does not work

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2 total messages Started by hpy_awad Tue, 27 Apr 2004 10:15

#88

Author: hpy_awad
Date: Tue, 27 Apr 2004 10:15

66 lines
2076 bytes

I wrote that program but spawnvp dows not call the exe files
hello1,hello2!!!

#include <stdio.h>
#include <conio.h>
#include <process.h>

//Tv Rental system menu version 1
  int user_selection();
  void display_menu();
  void call_program(int option,char *argv[]);
int main(int ,char *argv[])
{
 int option;
 do
 {
  display_menu();
  option=user_selection();
  if (option!=7) //Exit
   call_program(option,argv);
 }
 while (option!=7);
 return 0;
  }


 void display_menu()
 {
  clrscr();
  printf("1 hello1");
  printf("\n2 hello2");
  printf("\n3 exit");
 }

 int user_selection()
 {
  int opt;
  printf("\n Enter required option(1-3)   :   ");
  scanf("%1d",&opt);
  return (opt);
 }

 void call_program(int opt,char *argv[])
 {
 void delay();
 switch(opt)
  {
 case '1':
  spawnvp(0,"hello1.exe",argv);
  delay();
  break;
 case '2':
  spawnvp(0,"hello2.exe",argv);
  delay();
  break;
 default:
  printf("\n incoreect input");
  delay();
  exit(0);
  }
 }
 void delay()
 {
  int i;
  for (i=0;i<20000;i++);
 }

Re: spawnvp still does not work

#89

Author: Robert W Hand
Date: Tue, 27 Apr 2004 13:29

109 lines
3626 bytes

On 27 Apr 2004 03:15:31 -0700, ehab_aziz2001@yahoo.com
(hpy_awad@yahoo.com) wrote:

>I wrote that program but spawnvp dows not call the exe files
>hello1,hello2!!!

spawnvp works fine on my Windows XP system.  It is your C code that
fails.  Please see below.  I am answering from acllc-c++ that does
standard C and C++.  spawn and several other parts of your program are
extensions and not part of standard C.  

>
>#include <stdio.h>
>#include <conio.h>
>#include <process.h>

Non-standard headers, of course.

>
>//Tv Rental system menu version 1
>  int user_selection();
>  void display_menu();
>  void call_program(int option,char *argv[]);
>int main(int ,char *argv[])

You need a variable name for the first parameter.

>{
> int option;
> do
> {
>  display_menu();
>  option=user_selection();
>  if (option!=7) //Exit
>   call_program(option,argv);
> }
> while (option!=7);

Why make option 3 exit, but then use option 7 here?  Please be
consistent.

> return 0;
>  }
>
>
> void display_menu()
> {
>  clrscr();
>  printf("1 hello1");
>  printf("\n2 hello2");
>  printf("\n3 exit");

You should print lines with printf.  End the last printf with a new
line character.

> }
>
> int user_selection()
> {
>  int opt;
>  printf("\n Enter required option(1-3)   :   ");

Either flush or end with a new line.  

>  scanf("%1d",&opt);

Wrong conversion specifier.  ld is not for int.  Use "%d".  

>  return (opt);
> }
>
> void call_program(int opt,char *argv[])
> {
> void delay();

You are redeclaring delay.  No need for that.  Leave all the delays
out.  

> switch(opt)
>  {
> case '1':

opt is an integer.  You are comparing to character '1' that has a
different value than integer 1.  

case 1:

>  spawnvp(0,"hello1.exe",argv);
>  delay();
>  break;
> case '2':

case 2:

>  spawnvp(0,"hello2.exe",argv);
>  delay();
>  break;
> default:
>  printf("\n incoreect input");

Please spell user inteface messages properly.  

With those changes, the program compiled and ran as expected.  

Best wishes,

Bob

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