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) 1996-2022, PostgreSQL Global Development Group
  11  *
  12  * IDENTIFICATION
  13  *        src/backend/utils/misc/help_config.c
  14  *
  15  *-------------------------------------------------------------------------
  16  */
  17 #include "postgres.h"
  18
  19 #include <limits.h>
  20 #include <unistd.h>
  21
  22 #include "utils/guc_tables.h"
  23 #include "utils/help_config.h"
  24
  25
  26 /*
  27  * This union allows us to mix the numerous different types of structs
  28  * that we are organizing.
  29  */
  30 typedef union
  31 {
  32         struct config_generic generic;
  33         struct config_bool _bool;
  34         struct config_real real;
  35         struct config_int integer;
  36         struct config_string string;
  37         struct config_enum _enum;
  38 } mixedStruct;
  39
  40
  41 static void printMixedStruct(mixedStruct *structToPrint);
  42 static bool displayStruct(mixedStruct *structToDisplay);
  43
  44
  45 void
  46 GucInfoMain(void)
  47 {
  48         struct config_generic **guc_vars;
  49         int                     numOpts,
  50                                 i;
  51
  52         /* Initialize the guc_variables[] array */
  53         build_guc_variables();
  54
  55         guc_vars = get_guc_variables();
  56         numOpts = GetNumConfigOptions();
  57
  58         for (i = 0; i < numOpts; i++)
  59         {
  60                 mixedStruct *var = (mixedStruct *) guc_vars[i];
  61
  62                 if (displayStruct(var))
  63                         printMixedStruct(var);
  64         }
  65
  66         exit(0);
  67 }
  68
  69
  70 /*
  71  * This function will return true if the struct passed to it
  72  * should be displayed to the user.
  73  */
  74 static bool
  75 displayStruct(mixedStruct *structToDisplay)
  76 {
  77         return !(structToDisplay->generic.flags & (GUC_NO_SHOW_ALL |
  78                                                                                            GUC_NOT_IN_SAMPLE |
  79                                                                                            GUC_DISALLOW_IN_FILE));
  80 }
  81
  82
  83 /*
  84  * This function prints out the generic struct passed to it. It will print out
  85  * a different format, depending on what the user wants to see.
  86  */
  87 static void
  88 printMixedStruct(mixedStruct *structToPrint)
  89 {
  90         printf("%s\t%s\t%s\t",
  91                    structToPrint->generic.name,
  92                    GucContext_Names[structToPrint->generic.context],
  93                    _(config_group_names[structToPrint->generic.group]));
  94
  95         switch (structToPrint->generic.vartype)
  96         {
  97
  98                 case PGC_BOOL:
  99                         printf("BOOLEAN\t%s\t\t\t",
 100                                    (structToPrint->_bool.reset_val == 0) ?
 101                                    "FALSE" : "TRUE");
 102                         break;
 103
 104                 case PGC_INT:
 105                         printf("INTEGER\t%d\t%d\t%d\t",
 106                                    structToPrint->integer.reset_val,
 107                                    structToPrint->integer.min,
 108                                    structToPrint->integer.max);
 109                         break;
 110
 111                 case PGC_REAL:
 112                         printf("REAL\t%g\t%g\t%g\t",
 113                                    structToPrint->real.reset_val,
 114                                    structToPrint->real.min,
 115                                    structToPrint->real.max);
 116                         break;
 117
 118                 case PGC_STRING:
 119                         printf("STRING\t%s\t\t\t",
 120                                    structToPrint->string.boot_val ? structToPrint->string.boot_val : "");
 121                         break;
 122
 123                 case PGC_ENUM:
 124                         printf("ENUM\t%s\t\t\t",
 125                                    config_enum_lookup_by_value(&structToPrint->_enum,
 126                                                                                            structToPrint->_enum.boot_val));
 127                         break;
 128
 129                 default:
 130                         write_stderr("internal error: unrecognized run-time parameter type\n");
 131                         break;
 132         }
 133
 134         printf("%s\t%s\n",
 135                    (structToPrint->generic.short_desc == NULL) ? "" : _(structToPrint->generic.short_desc),
 136                    (structToPrint->generic.long_desc == NULL) ? "" : _(structToPrint->generic.long_desc));
 137 }