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Sourcecode: postgresql-8.4 version File versions

variables.h

/*
 * psql - the PostgreSQL interactive terminal
 *
 * Copyright (c) 2000-2009, PostgreSQL Global Development Group
 *
 * $PostgreSQL$
 */
#ifndef VARIABLES_H
#define VARIABLES_H

/*
 * This implements a sort of variable repository. One could also think of it
 * as a cheap version of an associative array. In each one of these
 * datastructures you can store name/value pairs.  There can also be an
 * "assign hook" function that is called whenever the variable's value is
 * changed.
 *
 * An "unset" operation causes the hook to be called with newval == NULL.
 *
 * Note: if value == NULL then the variable is logically unset, but we are
 * keeping the struct around so as not to forget about its hook function.
 */
typedef void (*VariableAssignHook) (const char *newval);

struct _variable
{
      char     *name;
      char     *value;
      VariableAssignHook assign_hook;
      struct _variable *next;
};

typedef struct _variable *VariableSpace;

/* Allowed chars in a variable's name */
#define VALID_VARIABLE_CHARS "abcdefghijklmnopqrstuvwxyz"\
                                           "ABCDEFGHIJKLMNOPQRSTUVWXYZ" "0123456789_"

VariableSpace CreateVariableSpace(void);
const char *GetVariable(VariableSpace space, const char *name);

bool        ParseVariableBool(const char *val);
int ParseVariableNum(const char *val,
                         int defaultval,
                         int faultval,
                         bool allowtrail);
int GetVariableNum(VariableSpace space,
                     const char *name,
                     int defaultval,
                     int faultval,
                     bool allowtrail);

void        PrintVariables(VariableSpace space);

bool        SetVariable(VariableSpace space, const char *name, const char *value);
bool        SetVariableAssignHook(VariableSpace space, const char *name, VariableAssignHook hook);
bool        SetVariableBool(VariableSpace space, const char *name);
bool        DeleteVariable(VariableSpace space, const char *name);

#endif   /* VARIABLES_H */

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