Line data    Source code

       1             : /*-------------------------------------------------------------------------
       2             :  *
       3             :  * version.c
       4             :  *      Routine to retrieve information of PG_VERSION
       5             :  *
       6             :  * Portions Copyright (c) 1996-2025, 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         390 : get_pg_version(const char *datadir, char **version_str)
      45             : {
      46             :     FILE       *version_fd;
      47             :     char        ver_filename[MAXPGPATH];
      48             :     char        buf[PG_VERSION_MAX_SIZE];
      49         390 :     int         v1 = 0,
      50         390 :                 v2 = 0;
      51             :     struct stat st;
      52             : 
      53         390 :     snprintf(ver_filename, sizeof(ver_filename), "%s/PG_VERSION",
      54             :              datadir);
      55             : 
      56         390 :     if ((version_fd = fopen(ver_filename, "r")) == NULL)
      57           0 :         pg_fatal("could not open version file \"%s\": %m", ver_filename);
      58             : 
      59         390 :     if (fstat(fileno(version_fd), &st) != 0)
      60           0 :         pg_fatal("could not stat file \"%s\": %m", ver_filename);
      61         390 :     if (st.st_size > PG_VERSION_MAX_SIZE)
      62           0 :         pg_fatal("file \"%s\" is too large", ver_filename);
      63             : 
      64         390 :     if (fscanf(version_fd, "%63s", buf) == 0 ||
      65         390 :         sscanf(buf, "%d.%d", &v1, &v2) < 1)
      66           0 :         pg_fatal("could not parse version file \"%s\"", ver_filename);
      67             : 
      68         390 :     fclose(version_fd);
      69             : 
      70         390 :     if (version_str)
      71             :     {
      72         350 :         *version_str = pg_malloc(PG_VERSION_MAX_SIZE);
      73         350 :         memcpy(*version_str, buf, st.st_size);
      74             :     }
      75             : 
      76         390 :     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         390 :         return v1 * 10000;
      85             :     }
      86             : }