Line data    Source code

       1              : /*-------------------------------------------------------------------------
       2              :  *
       3              :  * version.c
       4              :  *              Routine to retrieve information of PG_VERSION
       5              :  *
       6              :  * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
       7              :  * Portions Copyright (c) 1994, Regents of the University of California
       8              :  *
       9              :  *
      10              :  * IDENTIFICATION
      11              :  *        src/fe_utils/version.c
      12              :  *
      13              :  *-------------------------------------------------------------------------
      14              :  */
      15              : 
      16              : #include "postgres_fe.h"
      17              : 
      18              : #include <sys/stat.h>
      19              : 
      20              : #include "common/logging.h"
      21              : #include "fe_utils/version.h"
      22              : 
      23              : /*
      24              :  * Assumed maximum size of PG_VERSION.  This should be more than enough for
      25              :  * any version numbers that need to be handled.
      26              :  */
      27              : #define PG_VERSION_MAX_SIZE     64
      28              : 
      29              : /*
      30              :  * get_pg_version
      31              :  *
      32              :  * Retrieve the major version number of the given data folder, from
      33              :  * PG_VERSION.  The result returned is a version number, that can be used
      34              :  * for comparisons based on PG_VERSION_NUM.  For example, if PG_VERSION
      35              :  * contains "18\n", this function returns 180000.
      36              :  *
      37              :  * This supports both the pre-v10 and the post-v10 version numbering.
      38              :  *
      39              :  * Optionally, "version_str" can be specified to store the contents
      40              :  * retrieved from PG_VERSION.  It is allocated by this routine; the
      41              :  * caller is responsible for pg_free()-ing it.
      42              :  */
      43              : uint32
      44            0 : get_pg_version(const char *datadir, char **version_str)
      45              : {
      46            0 :         FILE       *version_fd;
      47            0 :         char            ver_filename[MAXPGPATH];
      48            0 :         char            buf[PG_VERSION_MAX_SIZE];
      49            0 :         int                     v1 = 0,
      50            0 :                                 v2 = 0;
      51            0 :         struct stat st;
      52              : 
      53            0 :         snprintf(ver_filename, sizeof(ver_filename), "%s/PG_VERSION",
      54            0 :                          datadir);
      55              : 
      56            0 :         if ((version_fd = fopen(ver_filename, "r")) == NULL)
      57            0 :                 pg_fatal("could not open version file \"%s\": %m", ver_filename);
      58              : 
      59            0 :         if (fstat(fileno(version_fd), &st) != 0)
      60            0 :                 pg_fatal("could not stat file \"%s\": %m", ver_filename);
      61            0 :         if (st.st_size > PG_VERSION_MAX_SIZE)
      62            0 :                 pg_fatal("file \"%s\" is too large", ver_filename);
      63              : 
      64            0 :         if (fscanf(version_fd, "%63s", buf) == 0 ||
      65            0 :                 sscanf(buf, "%d.%d", &v1, &v2) < 1)
      66            0 :                 pg_fatal("could not parse version file \"%s\"", ver_filename);
      67              : 
      68            0 :         fclose(version_fd);
      69              : 
      70            0 :         if (version_str)
      71              :         {
      72            0 :                 *version_str = pg_malloc(PG_VERSION_MAX_SIZE);
      73            0 :                 memcpy(*version_str, buf, st.st_size);
      74            0 :         }
      75              : 
      76            0 :         if (v1 < 10)
      77              :         {
      78              :                 /* pre-v10 style, e.g. 9.6.1 */
      79            0 :                 return v1 * 10000 + v2 * 100;
      80              :         }
      81              :         else
      82              :         {
      83              :                 /* post-v10 style, e.g. 10.1 */
      84            0 :                 return v1 * 10000;
      85              :         }
      86            0 : }