DosQuerySysInfo

Description

Returns values of static system variables.

Syntax

rc = DosQuerySysInfo( ulStartIndex, ulLastIndex, pDataBuffer, ulDataBufferLength );

Parameters

ULONG ulStartIndex (input): Index of the first info to query.
ULONG ulLastIndex (input): Index of the last info to query. Equal to ulStartIndex if it is the only wanted info.
PVOID pDataBuffer (output): Address to a data buffer to put the information in.
LONG ulDataBufferLength (input): Size of pDataBuffer. Valid values for ulStartIndex and ulLastIndex

No.	Name	Description	OS/2 Version
1	QSV_MAX_PATH_LENGTH	Maximum length of a path name (bytes). Use this when allocating filename buffers.	All
2	QSV_MAX_TEXT_SESSIONS	Maximum number of text sessions.	All
3	QSV_MAX_PM_SESSIONS	Maximum number of PM sessions.	All
4	QSV_MAX_VDM_SESSIONS	Maximum number of DOS sessions.	All
5	QSV_BOOT_DRIVE	Boot drive (1 = A:, 2 = B:, 3 = C, and so on).	All
6	QSV_DYN_PRI_VARIATION	Absolute(= 0)/Dynamic(= 1) priority.	All
7	QSV_MAX_WAIT	Maximum wait time (seconds).	All
8	QSV_MIN_SLICE	Minimum time slice allowed (milliseconds).	All
9	QSV_MAX_SLICE	Maximum time slice allowed (milliseconds).	All
10	QSV_PAGE_SIZE	Memory page size (bytes). Default 4096 bytes.	All
11	QSV_VERSION_MAJOR	Major version number.	All
12	QSV_VERSION_MINOR	Minor version number.	All
13	QSV_VERSION_REVISION	Revision letter.	All
14	QSV_MS_COUNT	Value of a 32-bit, free-running counter (milliseconds). Zero at boot time.	All
15	QSV_TIME_LOW	Low-order 32 bits of the time since January 1, 1980 (seconds).	All
16	QSV_TIME_HIGH	High-order 32 bits of the time since January 1, 1980 (seconds).	All
17	QSV_TOTPHYSMEM	Total number of bytes of physical memory.	All
18	QSV_TOTRESMEM	Total number of bytes of system-resident memory.	All
19	QSV_TOTAVAILMEM	Maximum number of bytes available for all processes in the system RIGHT NOW.	All
20	QSV_MAXPRMEM	Maximum number of bytes available for this process RIGHT NOW.	All
21	QSV_MAXSHMEM	Maximum number of shareable bytes available RIGHT NOW.	All
22	QSV_TIMER_INTERVAL	Timer interval (1/10 milliseconds).	All
23	QSV_MAX_COMP_LENGTH	Maximum length of one component in a path name (bytes).	All
24	QSV_FOREGROUND_FS_SESSION	Session ID of the current foreground full screen session. (any PM, VIO or Win-DOS session would be ID = 1).	Warp
25	QSV_FOREGROUND_PROCESS	Process ID of the current foreground process.	Warp
26	QSV_NUMPROCESSORS	Number of processors in the computer.	Warp

Returns

APIRET rc: Indicates if any error occured.

0	NO_ERROR
87	ERROR_INVALID_PARAMETER
111	ERROR_BUFFER_OVERFLOW

Include Info

#define INCL_DOSMISC
#include <os2.h>

Usage Explanation

DosQuerySysInfo queries different information about the system. and returns it in a buffer sent to it with the call.

Relevant Structures

Gotchas

Sample Code

ULONG aulBuffer[4];
APIRET rc;

rc = DosQuerySysInfo(QSV_VERSION_MAJOR, QSV_MS_COUNT,
		     (void *)aulBuffer, 4*sizeof(ULONG));
if(rc) {
  printf("Error! DosQuerySysInfo returned %d.\n",rc);
  return(-1);
}
else {
  printf("You are running version %d.%d revision %c.\n",
          aulBuffer[0], aulBuffer[1], (char) aulBuffer[2]);
  printf("Your system has been running %d hour(s) and %d minute(s).\n",
          aulBuffer[3]/3600000, (aulBuffer[3]%3600000)/60000);
}

This example queries and displays the maximum length for a path name and the total amount of physical memory in bytes.

#define INCL_DOSMISC       /* DOS Miscellaneous values */
#define INCL_DOSERRORS     /* DOS Error values         */
#include <os2.h>
#include <stdio.h>

int main(VOID)  {

  ULONG   aulSysInfo[QSV_MAX] = {0};       /* System Information Data Buffer */
  APIRET  rc                  = NO_ERROR;  /* Return code                    */

  rc = DosQuerySysInfo(1L,                 /* Request all available system   */
                       QSV_MAX,            /* information                    */
                       (PVOID)aulSysInfo,
                       sizeof(ULONG)*QSV_MAX);

  if (rc != NO_ERROR) {
     printf("DosQuerySysInfo error: return code = %u\n", rc);
     return 1;
  } else {
     printf("Maximum length for a path name is %u characters.\n",
             aulSysInfo[QSV_MAX_PATH_LENGTH-1]);  /* Max length of path name */

     printf("Total physical memory is %u bytes.\n",
             aulSysInfo[QSV_TOTPHYSMEM-1]);       /* Total physical memory   */
  } /* endif */

   return NO_ERROR;
}

Related Functions

Alternative

OS2Linux has an replacement alternative for this function not tested on OS/2. [1]