Re: Open 7.1 items - Mailing list pgsql-hackers

> > Actually, I have something from Oliver Elphick called pg_controldata:
>
> Could you send it to me so that I can find out how he gets the
> LC_COLLATE
> and LC_CTYPE from backend (assuming it tells backend locale not cients)
> ?
>
> >         $ pg_controldata
> >         Log file id:                          0
> >         Log file segment:                     5
> >         Last modified:                        Wed Feb  7 19:35:47 2001
> >         Database block size:                  8192
> >         Blocks per segment of large relation: 131072
> >         Catalog version number:               200101061
> >         LC_COLLATE:                           en_GB
> >         LC_CTYPE:                             en_GB
> >         Log archive directory:
> >
> > This looks quite valuable.  Do people want this in /contrib?  How does
> > this compare to your utility?
>
> Mine is an external C funtion, so it can easily be used from any client.
> And I intend to propose it into pg_locale.c ealy in 7.2 development.

His is an external C program also.  The C source is attached.

--
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 853-3000
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/* pg_controldata
 *
 * reads the data from $PGDATA/global/pg_control
 *
 * copyright (c) Oliver Elphick <olly@lfix.co.uk>, 2001;
 * licence: BSD
 *
*/

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <time.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>


typedef unsigned int uint32;

#include "config.h"
#include "access/xlogdefs.h"

/*
 * #include "access/xlog.h"
 * #include "c.h"
 */

/* The following definitions are extracted from access/xlog.h and its
 * recursive includes. There is too much initialisation needed if
 * they are included direct. Perhaps someone more knowledgeable can
 * fix that.
 */
typedef struct crc64
{
    uint32      crc1;
    uint32      crc2;
} crc64;

#define LOCALE_NAME_BUFLEN  128

typedef enum DBState
{
    DB_STARTUP = 0,
    DB_SHUTDOWNED,
    DB_SHUTDOWNING,
    DB_IN_RECOVERY,
    DB_IN_PRODUCTION
} DBState;


typedef struct ControlFileData
{
   crc64    crc;
   uint32      logId;         /* current log file id */
   uint32      logSeg;        /* current log file segment (1-based) */
   struct
    XLogRecPtr    checkPoint;    /* last check point record ptr */
   time_t      time;       /* time stamp of last modification */
   DBState     state;         /* see enum above */

   /*
    * this data is used to make sure that configuration of this DB is
    * compatible with the backend executable
    */
   uint32      blcksz;        /* block size for this DB */
   uint32      relseg_size;   /* blocks per segment of large relation */
   uint32      catalog_version_no;     /* internal version number */
   /* active locales --- "C" if compiled without USE_LOCALE: */
   char     lc_collate[LOCALE_NAME_BUFLEN];
   char     lc_ctype[LOCALE_NAME_BUFLEN];

   /*
    * important directory locations
    */
   char     archdir[MAXPGPATH];     /* where to move offline log files */
} ControlFileData;

int main() {
    ControlFileData ControlFile;
    int fd;
    char ControlFilePath[MAXPGPATH];
    char *DataDir;
    char tmdt[32];

    DataDir = getenv("PGDATA");
    if ( DataDir == NULL ) {
        fprintf(stderr,"PGDATA is not defined\n");
        exit(1);
    }

    snprintf(ControlFilePath, MAXPGPATH, "%s/global/pg_control", DataDir);

    if ((fd = open(ControlFilePath, O_RDONLY)) == -1) {
        perror("Failed to open $PGDATA/global/pg_control for reading");
        exit(2);
    }

    read(fd, &ControlFile, sizeof(ControlFileData));
    strftime(tmdt, 32, "%c", localtime(&(ControlFile.time)));

    printf("Log file id:                          %u\n"
           "Log file segment:                     %u\n"
             "Last modified:                        %s\n"
             "Database block size:                  %u\n"
             "Blocks per segment of large relation: %u\n"
             "Catalog version number:               %u\n"
             "LC_COLLATE:                           %s\n"
             "LC_CTYPE:                             %s\n"
             "Log archive directory:                %s\n",
             ControlFile.logId,
             ControlFile.logSeg,
             tmdt,
             ControlFile.blcksz,
             ControlFile.relseg_size,
             ControlFile.catalog_version_no,
             ControlFile.lc_collate,
             ControlFile.lc_ctype,
             ControlFile.archdir);

    return (0);
}