SplEnumPrinter: Difference between revisions
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Revision as of 04:13, 29 February 2020
This function lists print destinations in the system.
Syntax
SplEnumPrinter(PSZComputerName, ulLevel, flType, pBuf, cbBuf, pcReturned, pcTotal, pcbNeeded, pReserved);
Parameters
- PSZComputerName (PSZ) - input
- Name of computer where queues are to be listed.
- This must be NULL.
- ulLevel (ULONG) - input
- Level of detail required.
- This must be 0.
- flType (ULONG) - input
- Type of print destinations required.
- SPL_PR_QUEUE
- Return only queues
- SPL_PR_DIRECT_DEVICE
- Return only direct print devices
- SPL_PR_QUEUED_DEVICE
- Return only queued print devices
- SPL_PR_LOCAL_ONLY
- Return only local print destinations
- pBuf (PVOID) - output
- Buffer.
- The returned contents in the buffer are as follows:
- ulLevel Buffer Contents
- 0 An array of PRINTERINFO structures.
- When the names of print destinations are returned, calls can be made to SplQueryQueue or SplQueryDevice to find out further information about the print destination.
- cbBuf (ULONG) - input
- Size, in bytes, of Buffer.
- It must be greater than 0.
- pcReturned (PULONG) - output
- Number of entries returned.
- pcTotal (PULONG) - output
- Number of entries available.
- pcbNeeded (PULONG) - output
- Size in bytes of available information.
- A value of 0 specifies that the size is not known.
- pReserved (PVOID) - output
- Reserved value, must be NULL.
Return Code
- rc (SPLERR) - returns
- Return code.
- NO_ERROR (0)
- No errors occurred.
- ERROR_NOT_SUPPORTED (50)
- This request is not supported by the network.
- ERROR_INVALID_PARAMETER (87)
- An invalid parameter is specified.
- ERROR_INVALID_LEVEL (124)
- The level parameter is invalid.
- ERROR_MORE_DATA (234)
- Additional data is available.
- NERR_NetNotStarted (2102)
- The network program is not started.
- NERR_BufTooSmall (2123)
- The API return buffer is too small.
Calling Sequence
#define INCL_SPL /* Or use INCL_PM, */
#include <os2.h>
PSZ PSZComputerName; /* Name of computer where queues are to be listed. */
ULONG ulLevel; /* Level of detail required. */
ULONG flType; /* Type of print destinations required. */
PVOID pBuf; /* Buffer. */
ULONG cbBuf; /* Size, in bytes, of Buffer. */
PULONG pcReturned; /* Number of entries returned. */
PULONG pcTotal; /* Number of entries available. */
PULONG pcbNeeded; /* Size in bytes of available information. */
PVOID pReserved; /* Reserved value, must be NULL. */
SPLERR rc; /* Return code. */
rc = SplEnumPrinter(PSZComputerName, ulLevel,
flType, pBuf, cbBuf, pcReturned, pcTotal,
pcbNeeded, pReserved);
Sample
This example code will print out all queues and printers for the local computer. It will print out both printers that are attached to a queue, and those that are direct printers.
#define INCL_SPL
#define INCL_SPLDOSPRINT
#define INCL_SPLERRORS
#include <os2.h>
#include <stdio.h> /* for printf function */
INT main ()
{
PVOID pBuf;
ULONG fsType ;
ULONG cbBuf ;
ULONG cRes ;
ULONG cTotal ;
ULONG cbNeeded ;
SPLERR splerr = 0 ;
PPRINTERINFO pRes ;
/* Set fsType to use all the flags. We will print out local device/queues.*/
fsType = SPL_PR_QUEUE | SPL_PR_DIRECT_DEVICE |
SPL_PR_QUEUED_DEVICE | SPL_PR_LOCAL_ONLY;
/* Make function call with cbBuf equal to zero to get a return in cbNeeded*/
/* of the number of bytes needed for buffer to hold all the information */
splerr = SplEnumPrinter ( NULL,0 ,fsType ,NULL ,NULL ,&cRes ,
&cTotal,&cbNeeded ,NULL ) ;
/* The error return code will be one of the two following codes if */
/* all the parameters were correct. Otherwise it could be */
/* ERROR_INVALID_PARAMETER. */
if ( splerr == ERROR_MORE_DATA || splerr == NERR_BufTooSmall )
{
/* Allocate memory for the buffer using the count of bytes that were */
/* returned in cbNeeded. For simplicity, no error checking is done. */
DosAllocMem( &pBuf, cbNeeded,
PAG_READ|PAG_WRITE|PAG_COMMIT);
/* Set count of bytes in buffer to value used to allocate buffer. */
cbBuf = cbNeeded;
/* Call function again with the correct buffer size. */
splerr = SplEnumPrinter ( NULL,0 ,fsType ,pBuf ,cbBuf ,&cRes ,
&cTotal,&cbNeeded,NULL);
/* If there are any returned structures in the buffer, then we will */
/* print out some of the information. */
if (cRes)
{
pRes = (PPRINTERINFO)pBuf ;
while ( cRes-- )
{
/* Look at the flType element in the pRes structure to determine */
/* what type of print destination the structure represents. */
switch (pRes[cRes].flType)
{
case SPL_PR_QUEUE:
printf("Print destination %s is a queue.\n",
pRes[cRes].pszPrintDestinationName) ;
break;
case SPL_PR_QUEUED_DEVICE:
printf("Print destination %s is a queued printer.\n",
pRes[cRes].pszPrintDestinationName) ;
break;
case SPL_PR_DIRECT_DEVICE:
printf("Print destination %s is a direct printer.\n",
pRes[cRes].pszPrintDestinationName) ;
}
printf("Description -
%s\n\n",pRes[cRes].pszDescription) ;
}
}
DosFreeMem(pBuf);
}
else
{
/* If we had any other return code other than ERROR_MORE_DATA or */
/* NERR_BufTooSmall, we will print out the following information. */
printf("SplEnumPrinter error= %ld \n",splerr);
}
DosExit( EXIT_PROCESS , 0 ) ;
return (splerr);
}