/* -*-pgsql-c-*- *//* * Scanner for the configuration file * * Copyright (c) 2000-2005, PostgreSQL Global Development Group * * $PostgreSQL: pgsql/src/backend/utils/misc/guc-file.l,v 1.32.2.2 2006/01/02 19:55:31 tgl Exp $ */%{#include "postgres.h"#include <unistd.h>#include <ctype.h>#include "miscadmin.h"#include "storage/fd.h"#include "utils/guc.h"/* Avoid exit() on fatal scanner errors (a bit ugly -- see yy_fatal_error) */#undef fprintf#define fprintf(file, fmt, msg)  ereport(ERROR, (errmsg_internal("%s", msg)))static unsigned ConfigFileLineno;enum {	GUC_ID = 1,	GUC_STRING = 2,	GUC_INTEGER = 3,	GUC_REAL = 4,	GUC_EQUALS = 5,	GUC_UNQUOTED_STRING = 6,	GUC_QUALIFIED_ID = 7,	GUC_EOL = 99,	GUC_ERROR = 100};/* prototype, so compiler is happy with our high warnings setting */int GUC_yylex(void);static char *GUC_scanstr(const char *s);%}%option 8bit%option never-interactive%option nodefault%option nounput%option noyywrapSIGN            ("-"|"+")DIGIT           [0-9]HEXDIGIT        [0-9a-fA-F]INTEGER         {SIGN}?({DIGIT}+|0x{HEXDIGIT}+)EXPONENT        [Ee]{SIGN}?{DIGIT}+REAL            {SIGN}?{DIGIT}*"."{DIGIT}*{EXPONENT}?LETTER          [A-Za-z_\200-\377]LETTER_OR_DIGIT [A-Za-z_0-9\200-\377]ID              {LETTER}{LETTER_OR_DIGIT}*QUALIFIED_ID    {ID}"."{ID}UNQUOTED_STRING {LETTER}({LETTER_OR_DIGIT}|[-._:/])*STRING          \'([^'\\\n]|\\.|\'\')*\'%%\n              ConfigFileLineno++; return GUC_EOL;[ \t\r]+        /* eat whitespace */#.*             /* eat comment (.* matches anything until newline) */{ID}            return GUC_ID;{QUALIFIED_ID}  return GUC_QUALIFIED_ID;{STRING}        return GUC_STRING;{UNQUOTED_STRING} return GUC_UNQUOTED_STRING;{INTEGER}       return GUC_INTEGER;{REAL}          return GUC_REAL;=               return GUC_EQUALS;.               return GUC_ERROR;%%struct name_value_pair{	char       *name;	char       *value;	struct name_value_pair *next;};/* * Free a list of name/value pairs, including the names and the values */static voidfree_name_value_list(struct name_value_pair * list){	struct name_value_pair *item;	item = list;	while (item)	{		struct name_value_pair *save;		save = item->next;		pfree(item->name);		pfree(item->value);		pfree(item);		item = save;	}}/* * Official function to read and process the configuration file. The * parameter indicates in what context the file is being read --- either * postmaster startup (including standalone-backend startup) or SIGHUP. * All options mentioned in the configuration file are set to new values. * If an error occurs, no values will be changed. */voidProcessConfigFile(GucContext context){	int			elevel;	int			token;	char	   *opt_name, *opt_value;	struct name_value_pair *item, *head, *tail;	FILE	   *fp;	Assert(context == PGC_POSTMASTER || context == PGC_SIGHUP);	if (context == PGC_SIGHUP)	{		/*		 * To avoid cluttering the log, only the postmaster bleats loudly		 * about problems with the config file.		 */		elevel = IsUnderPostmaster ? DEBUG2 : LOG;	}	else		elevel = ERROR;	fp = AllocateFile(ConfigFileName, "r");	if (!fp)	{		ereport(elevel,				(errcode_for_file_access(),				 errmsg("could not open configuration file \"%s\": %m",						ConfigFileName)));		return;	}	/*	 * Parse	 */	yyrestart(fp);	head = tail = NULL;	opt_name = opt_value = NULL;	ConfigFileLineno = 1;	/* This loop iterates once per logical line */	while ((token = yylex()))	{		if (token == GUC_EOL)	/* empty or comment line */			continue;		/* first token on line is option name */		if (token != GUC_ID && token != GUC_QUALIFIED_ID)			goto parse_error;		opt_name = pstrdup(yytext);		/* next we have an optional equal sign; discard if present */		token = yylex();		if (token == GUC_EQUALS)			token = yylex();		/* now we must have the option value */		if (token != GUC_ID &&			token != GUC_STRING && 			token != GUC_INTEGER && 			token != GUC_REAL && 			token != GUC_UNQUOTED_STRING)			goto parse_error;		if (token == GUC_STRING)	/* strip quotes and escapes */			opt_value = GUC_scanstr(yytext);		else			opt_value = pstrdup(yytext);		/* now we'd like an end of line, or possibly EOF */		token = yylex();		if (token != GUC_EOL && token != 0)			goto parse_error;		/* OK, save the option name and value */		if (strcmp(opt_name, "custom_variable_classes") == 0)		{			/*			 * This variable must be processed first as it controls			 * the validity of other variables; so apply immediately.			 */			if (!set_config_option(opt_name, opt_value, context,								   PGC_S_FILE, false, true))			{				pfree(opt_name);				pfree(opt_value);				FreeFile(fp);				goto cleanup_exit;			}			pfree(opt_name);			pfree(opt_value);		}		else		{			/* append to list */			item = palloc(sizeof *item);			item->name = opt_name;			item->value = opt_value;			item->next = NULL;			if (!head)				head = item;			else				tail->next = item;			tail = item;		}		/* break out of loop if read EOF, else loop for next line */		if (token == 0)			break;	}	FreeFile(fp);	/*	 * Check if all options are valid	 */	for(item = head; item; item=item->next)	{		if (!set_config_option(item->name, item->value, context,							   PGC_S_FILE, false, false))			goto cleanup_exit;	}	/* If we got here all the options parsed okay, so apply them. */	for(item = head; item; item=item->next)	{		set_config_option(item->name, item->value, context,						  PGC_S_FILE, false, true);	} cleanup_exit:	free_name_value_list(head);	return; parse_error:	FreeFile(fp);	free_name_value_list(head);	if (token == GUC_EOL || token == 0)		ereport(elevel,				(errcode(ERRCODE_SYNTAX_ERROR),				 errmsg("syntax error in file \"%s\" line %u, near end of line",						ConfigFileName, ConfigFileLineno - 1)));	else		ereport(elevel,				(errcode(ERRCODE_SYNTAX_ERROR),				 errmsg("syntax error in file \"%s\" line %u, near token \"%s\"", 						ConfigFileName, ConfigFileLineno, yytext)));}/* *		scanstr * * Strip the quotes surrounding the given string, and collapse any embedded * '' sequences and backslash escapes. * * the string returned is palloc'd and should eventually be pfree'd by the * caller. */static char *GUC_scanstr(const char *s){	char	   *newStr;	int			len,				i,				j;	Assert(s != NULL && s[0] == '\'');	len = strlen(s);	Assert(len >= 2);	Assert(s[len-1] == '\'');	/* Skip the leading quote; we'll handle the trailing quote below */	s++, len--;	/* Since len still includes trailing quote, this is enough space */	newStr = palloc(len);	for (i = 0, j = 0; i < len; i++)	{		if (s[i] == '\\')		{			i++;			switch (s[i])			{				case 'b':					newStr[j] = '\b';					break;				case 'f':					newStr[j] = '\f';					break;				case 'n':					newStr[j] = '\n';					break;				case 'r':					newStr[j] = '\r';					break;				case 't':					newStr[j] = '\t';					break;				case '0':				case '1':				case '2':				case '3':				case '4':				case '5':				case '6':				case '7':					{						int			k;						long		octVal = 0;						for (k = 0;							 s[i + k] >= '0' && s[i + k] <= '7' && k < 3;							 k++)							octVal = (octVal << 3) + (s[i + k] - '0');						i += k - 1;						newStr[j] = ((char) octVal);					}					break;				default:					newStr[j] = s[i];					break;			}					/* switch */		}		else if (s[i] == '\'' && s[i+1] == '\'')		{			/* doubled quote becomes just one quote */			newStr[j] = s[++i];		}		else			newStr[j] = s[i];		j++;	}	/* We copied the ending quote to newStr, so replace with \0 */	Assert(j > 0 && j <= len);	newStr[--j] = '\0';	return newStr;}