src/backend/utils/misc/help_config.c

   1 /*-------------------------------------------------------------------------
   2  * help_config.c
   3  *
   4  * Displays available options under grand unified configuration scheme
   5  *
   6  * Options whose flag bits are set to GUC_NO_SHOW_ALL, GUC_NOT_IN_SAMPLE,
   7  * or GUC_DISALLOW_IN_FILE are not displayed, unless the user specifically
   8  * requests that variable by name
   9  *
  10  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  11  *
  12  * IDENTIFICATION
  13  *        $PostgreSQL$
  14  *
  15  *-------------------------------------------------------------------------
  16  */
  17 #include "postgres.h"
  18
  19 #include <float.h>
  20 #include <limits.h>
  21 #include <unistd.h>
  22
  23 #include "utils/guc_tables.h"
  24 #include "utils/help_config.h"
  25
  26
  27 /*
  28  * This union allows us to mix the numerous different types of structs
  29  * that we are organizing.
  30  */
  31 typedef union
  32 {
  33         struct config_generic generic;
  34         struct config_bool bool;
  35         struct config_real real;
  36         struct config_int integer;
  37         struct config_string string;
  38         struct config_enum _enum;
  39 } mixedStruct;
  40
  41
  42 static void printMixedStruct(mixedStruct *structToPrint);
  43 static bool displayStruct(mixedStruct *structToDisplay);
  44
  45
  46 int
  47 GucInfoMain(void)
  48 {
  49         struct config_generic **guc_vars;
  50         int                     numOpts,
  51                                 i;
  52
  53         /* Initialize the guc_variables[] array */
  54         build_guc_variables();
  55
  56         guc_vars = get_guc_variables();
  57         numOpts = GetNumConfigOptions();
  58
  59         for (i = 0; i < numOpts; i++)
  60         {
  61                 mixedStruct *var = (mixedStruct *) guc_vars[i];
  62
  63                 if (displayStruct(var))
  64                         printMixedStruct(var);
  65         }
  66
  67         return 0;
  68 }
  69
  70
  71 /*
  72  * This function will return true if the struct passed to it
  73  * should be displayed to the user.
  74  */
  75 static bool
  76 displayStruct(mixedStruct *structToDisplay)
  77 {
  78         return !(structToDisplay->generic.flags & (GUC_NO_SHOW_ALL |
  79                                                                                            GUC_NOT_IN_SAMPLE |
  80                                                                                            GUC_DISALLOW_IN_FILE));
  81 }
  82
  83
  84 /*
  85  * This function prints out the generic struct passed to it. It will print out
  86  * a different format, depending on what the user wants to see.
  87  */
  88 static void
  89 printMixedStruct(mixedStruct *structToPrint)
  90 {
  91         printf("%s\t%s\t%s\t",
  92                    structToPrint->generic.name,
  93                    GucContext_Names[structToPrint->generic.context],
  94                    _(config_group_names[structToPrint->generic.group]));
  95
  96         switch (structToPrint->generic.vartype)
  97         {
  98
  99                 case PGC_BOOL:
 100                         printf("BOOLEAN\t%s\t\t\t",
 101                                    (structToPrint->bool.reset_val == 0) ?
 102                                    "FALSE" : "TRUE");
 103                         break;
 104
 105                 case PGC_INT:
 106                         printf("INTEGER\t%d\t%d\t%d\t",
 107                                    structToPrint->integer.reset_val,
 108                                    structToPrint->integer.min,
 109                                    structToPrint->integer.max);
 110                         break;
 111
 112                 case PGC_REAL:
 113                         printf("REAL\t%g\t%g\t%g\t",
 114                                    structToPrint->real.reset_val,
 115                                    structToPrint->real.min,
 116                                    structToPrint->real.max);
 117                         break;
 118
 119                 case PGC_STRING:
 120                         printf("STRING\t%s\t\t\t",
 121                                    structToPrint->string.boot_val ? structToPrint->string.boot_val : "");
 122                         break;
 123
 124                 case PGC_ENUM:
 125                         printf("ENUM\t%s\t\t\t",
 126                                    config_enum_lookup_by_value(&structToPrint->_enum,
 127                                                                                            structToPrint->_enum.boot_val));
 128                         break;
 129
 130                 default:
 131                         write_stderr("internal error: unrecognized run-time parameter type\n");
 132                         break;
 133         }
 134
 135         printf("%s\t%s\n",
 136                    (structToPrint->generic.short_desc == NULL) ? "" : _(structToPrint->generic.short_desc),
 137                    (structToPrint->generic.long_desc == NULL) ? "" : _(structToPrint->generic.long_desc));
 138 }