Re: Submit a program call

[Terrence Enger <tenger@xxxxxxxxxxxxxxxx>]

All,

Sorry to come so late.  If I bring a whine to go with your chheese, will
you still let me come join the party <grin />?

This solution is much clearer than declaring an undifferentiated
char*argv[]; thank you again, Barbara.

However, I see a problem:  there is no null terminator for userid.  That
1999999999 values of SALARY() do not show the bug is just bad luck.
Okay, 2000000000 values if you count minus zero; stop being so picky!

Here is what I came up with.  It additionally trims unquoted trailing
blanks from USERID(); note DFT(''), which makes an omitted USERID() into
the null string rather than a blank.

I must be overlooking something in some standard library which already
does this.  Any pointers?

Cheers,
Terry.

========== start command source
/* parms pgm(aa4721) */
             CMD        PROMPT('Command with 3 arguments')
             PARM       KWD(USERID) TYPE(*CHAR) LEN(10) +
                        VARY(*YES *INT2) dft('')
             PARM       KWD(SALARY) TYPE(*DEC) LEN(10 2)
             PARM       KWD(CUSTNO) TYPE(*INT4)
========== start program source
#include <stdio.h>
#include <decimal.h>
#include <assert.h>
#include <string.h>

/* from the command definition
*/
#define MAXLEN_USERID   10

typedef struct varying2
{
  short int len;
  char      data[1];  /* ycch!  This relies on the lack of bound
checking */
                      /* in C.  And we had better not instantiate one of
*/
                      /* these, at least not in a straightforward way.
*/
} varying2_t;

/* I can't believe that I have to write this myself!
*/
/*
*/
void
varying2ToCharStar( varying2_t * v2
                  , short int destMaxLen
                  , char * dest )
{
  assert( v2->len < destMaxLen );       /* Ensure destination is big
enuf */
  strncpy( dest, v2->data, v2->len );   /* data from caller
*/
  dest[ v2->len ] = '\0';               /* terminating null
*/

} /* varying2ToCharStar() */

typedef struct inputArguments
{
  char * pgmname;
  varying2_t * userid;
  decimal(10,2) * salary;
  int * custno;
} main_args_t;

void main(int argc, main_args_t * main_args)
{
  char userid[ 1 + MAXLEN_USERID ];
  varying2ToCharStar( main_args->userid, MAXLEN_USERID, userid );
  printf("1st arg = %s, userid = %s, 3rd arg = %D(10,2), 4th arg = %d",
         main_args->pgmname, userid,
         *main_args->salary, *main_args->custno);
}
========== end source code



On Wed, 2009-02-25 at 10:04 -0600, Elvis Budimlic wrote:
> Both Barbara's and mine example ought to work. I like Barbara's approach
> better as it allows handling of varying data types, so I just tried it out.
> Here are the results:
>
> /*START C member source */
> #include <stdio.h>                                                      
> #include <decimal.h>                                                    
>                                                                         
> typedef struct inputArguments                                           
> {                                                                       
>   char * pgmname;                                                       
>   char * userid;                                                        
>   decimal(10,2) * salary;                                               
>   int * custno;                                                         
> } main_args_t;                                                          
>                                                                         
> void main(int argc, main_args_t * main_args)                            
> {                                                                       
>   printf("1st arg = %s, 2nd arg = %s, 3rd arg = %D(10,2), 4th arg = %d",
>          main_args->pgmname, main_args->userid,                         
>          *main_args->salary, *main_args->custno);                       
> }                                                                       
> /* END C member source */
>
> Not sure if you're aware of it, but argv[0] is initialized implicitly by the
> OS to the fully qualified program name (i.e. ELVIS/INPTST). So, first
> argument is always a char *, as illustrated in the struct with the leading
> pgmname variable.
> To compile the C source, I used this command:
>
> CRTBNDC PGM(ELVIS/INPTST) SRCFILE(ELVIS/C) OUTPUT(*print) DBGVIEW(*ALL)
>
> /* START *CMD source */
>              CMD        PROMPT('Command with 3 arguments')  
>              PARM       KWD(USERID) TYPE(*CHAR) LEN(10)     
>              PARM       KWD(SALARY) TYPE(*DEC) LEN(10 2)    
>              PARM       KWD(CUSTNO) TYPE(*INT4)             
> /* END *CMD source */
>
> Note that there is no 'pgmname' keyword, as it's passed implicitly by the
> OS.
> To compile the *CMD source, I used this command:
>
> CRTCMD CMD(ELVIS/INPTST) PGM(ELVIS/INPTST) SRCFILE(ELVIS/CMD)
>
> Then, to test the program, I invoked my command as:
>
> INPTST USERID(MYUSERID) SALARY(3300.44) CUSTNO(77)
>
> And got the following output:
>
> 1st arg = ELVIS/INPTST, 2nd arg = MYUSERID  , 3rd arg = 3300.44, 4th arg =
> 77
>
> Hth, Elvis
>
> Celebrating 11-Years of SQL Performance Excellence on IBM i, i5/OS and
> OS/400
> www.centerfieldtechnology.com
>
>
> -----Original Message-----
> Subject: Re: [C400-L] Submit a program call
>
> Back again... I tried out both Elvis' and Barbara's (I hope a first name
> basis is ok!) solutions but I can't even get a compile:
>
> "A parameter of type "main_args_t *" cannot be initialized with an
> expression of type "char **"."
>
> After taking a closer look at the language ref manual it seems as though one
> *has* to pass char **? Just seems so incredibly awkward that I, just to
> perform a simple SBMJOB on the call to this program, would need to go
> through a CL program and manually append null terminators etc... (which is
> what they do in the Programmer's guide when calling C from CL).