copy.c

PostgreSQL 8.1.4的源码 适用于Linux下的开源数据库系统

					for (;;)
					{
						token = strtokx(NULL, whitespace, ",", "\"",
										0, false, pset.encoding);
						if (!token || strchr(",", token[0]))
							goto error;
						if (!result->force_notnull_list)
							result->force_notnull_list = pg_strdup(token);
						else
							xstrcat(&result->force_notnull_list, token);
						token = strtokx(NULL, whitespace, ",", "\"",
										0, false, pset.encoding);
						if (!token || token[0] != ',')
							break;
						xstrcat(&result->force_notnull_list, token);
					}
				}
				else
					goto error;
			}
			else
				goto error;

			if (fetch_next)
				token = strtokx(NULL, whitespace, NULL, NULL,
								0, false, pset.encoding);
		}
	}

	free(line);

	return result;

error:
	if (token)
		psql_error("\\copy: parse error at \"%s\"\n", token);
	else
		psql_error("\\copy: parse error at end of line\n");
	free_copy_options(result);
	free(line);

	return NULL;
}



/*
 * Execute a \copy command (frontend copy). We have to open a file, then
 * submit a COPY query to the backend and either feed it data from the
 * file or route its response into the file.
 */
bool
do_copy(const char *args)
{
	PQExpBufferData query;
	FILE	   *copystream;
	struct copy_options *options;
	PGresult   *result;
	bool		success;
	struct stat st;

	/* parse options */
	options = parse_slash_copy(args);

	if (!options)
		return false;

	initPQExpBuffer(&query);

	printfPQExpBuffer(&query, "COPY ");
	if (options->binary)
		appendPQExpBuffer(&query, "BINARY ");

	appendPQExpBuffer(&query, "%s ", options->table);

	if (options->column_list)
		appendPQExpBuffer(&query, "%s ", options->column_list);

	/* Uses old COPY syntax for backward compatibility 2002-06-19 */
	if (options->oids)
		appendPQExpBuffer(&query, "WITH OIDS ");

	if (options->from)
		appendPQExpBuffer(&query, "FROM STDIN");
	else
		appendPQExpBuffer(&query, "TO STDOUT");


	/* Uses old COPY syntax for backward compatibility 2002-06-19 */
	if (options->delim)
	{
		if (options->delim[0] == '\'')
			appendPQExpBuffer(&query, " USING DELIMITERS %s",
							  options->delim);
		else
			appendPQExpBuffer(&query, " USING DELIMITERS '%s'",
							  options->delim);
	}

	/* There is no backward-compatible CSV syntax */
	if (options->null)
	{
		if (options->null[0] == '\'')
			appendPQExpBuffer(&query, " WITH NULL AS %s", options->null);
		else
			appendPQExpBuffer(&query, " WITH NULL AS '%s'", options->null);
	}

	if (options->csv_mode)
		appendPQExpBuffer(&query, " CSV");

	if (options->header)
		appendPQExpBuffer(&query, " HEADER");

	if (options->quote)
	{
		if (options->quote[0] == '\'')
			appendPQExpBuffer(&query, " QUOTE AS %s", options->quote);
		else
			appendPQExpBuffer(&query, " QUOTE AS '%s'", options->quote);
	}

	if (options->escape)
	{
		if (options->escape[0] == '\'')
			appendPQExpBuffer(&query, " ESCAPE AS %s", options->escape);
		else
			appendPQExpBuffer(&query, " ESCAPE AS '%s'", options->escape);
	}

	if (options->force_quote_list)
		appendPQExpBuffer(&query, " FORCE QUOTE %s", options->force_quote_list);

	if (options->force_notnull_list)
		appendPQExpBuffer(&query, " FORCE NOT NULL %s", options->force_notnull_list);

	if (options->file)
		canonicalize_path(options->file);

	if (options->from)
	{
		if (options->file)
			copystream = fopen(options->file, PG_BINARY_R);
		else if (!options->psql_inout)
			copystream = pset.cur_cmd_source;
		else
			copystream = stdin;
	}
	else
	{
		if (options->file)
			copystream = fopen(options->file, "w");
		else if (!options->psql_inout)
			copystream = pset.queryFout;
		else
			copystream = stdout;
	}

	if (!copystream)
	{
		psql_error("%s: %s\n",
				   options->file, strerror(errno));
		free_copy_options(options);
		return false;
	}

	/* make sure the specified file is not a directory */
	fstat(fileno(copystream), &st);
	if (S_ISDIR(st.st_mode))
	{
		fclose(copystream);
		psql_error("%s: cannot copy from/to a directory\n",
				   options->file);
		free_copy_options(options);
		return false;
	}

	result = PSQLexec(query.data, true);
	termPQExpBuffer(&query);

	switch (PQresultStatus(result))
	{
		case PGRES_COPY_OUT:
			success = handleCopyOut(pset.db, copystream);
			break;
		case PGRES_COPY_IN:
			success = handleCopyIn(pset.db, copystream);
			break;
		case PGRES_NONFATAL_ERROR:
		case PGRES_FATAL_ERROR:
		case PGRES_BAD_RESPONSE:
			success = false;
			psql_error("\\copy: %s", PQerrorMessage(pset.db));
			break;
		default:
			success = false;
			psql_error("\\copy: unexpected response (%d)\n", PQresultStatus(result));
	}

	PQclear(result);

	if (options->file != NULL)
	{
		if (fclose(copystream) != 0)
		{
			psql_error("%s: %s\n", options->file, strerror(errno));
			success = false;
		}
	}
	free_copy_options(options);
	return success;
}


#define COPYBUFSIZ 8192			/* size doesn't matter */


/*
 * handleCopyOut
 * receives data as a result of a COPY ... TO stdout command
 *
 * If you want to use COPY TO in your application, this is the code to steal :)
 *
 * conn should be a database connection that you just called COPY TO on
 * (and which gave you PGRES_COPY_OUT back);
 * copystream is the file stream you want the output to go to
 */
bool
handleCopyOut(PGconn *conn, FILE *copystream)
{
	bool		copydone = false;		/* haven't started yet */
	char		copybuf[COPYBUFSIZ];
	int			ret;

	while (!copydone)
	{
		ret = PQgetline(conn, copybuf, COPYBUFSIZ);

		if (copybuf[0] == '\\' &&
			copybuf[1] == '.' &&
			copybuf[2] == '\0')
		{
			copydone = true;	/* we're at the end */
		}
		else
		{
			fputs(copybuf, copystream);
			switch (ret)
			{
				case EOF:
					copydone = true;
					/* FALLTHROUGH */
				case 0:
					fputc('\n', copystream);
					break;
				case 1:
					break;
			}
		}
	}
	fflush(copystream);
	ret = !PQendcopy(conn);
	ResetCancelConn();
	return ret;
}



/*
 * handleCopyIn
 * receives data as a result of a COPY ... FROM stdin command
 *
 * Again, if you want to use COPY FROM in your application, copy this.
 *
 * conn should be a database connection that you just called COPY FROM on
 * (and which gave you PGRES_COPY_IN back);
 * copystream is the file stream you want the input to come from
 */

bool
handleCopyIn(PGconn *conn, FILE *copystream)
{
	const char *prompt;
	bool		copydone = false;
	bool		firstload;
	bool		linedone;
	bool		saw_cr = false;
	char		copybuf[COPYBUFSIZ];
	char	   *s;
	int			bufleft;
	int			c = 0;
	int			ret;
	unsigned int linecount = 0;

	/* Prompt if interactive input */
	if (isatty(fileno(copystream)))
	{
		if (!QUIET())
			puts(_("Enter data to be copied followed by a newline.\n"
				   "End with a backslash and a period on a line by itself."));
		prompt = get_prompt(PROMPT_COPY);
	}
	else
		prompt = NULL;

	while (!copydone)
	{							/* for each input line ... */
		if (prompt)
		{
			fputs(prompt, stdout);
			fflush(stdout);
		}
		firstload = true;
		linedone = false;

		while (!linedone)
		{						/* for each bufferload in line ... */
			/* Fetch string until \n, EOF, or buffer full */
			s = copybuf;
			for (bufleft = COPYBUFSIZ - 1; bufleft > 0; bufleft--)
			{
				c = getc(copystream);
				if (c == EOF)
				{
					linedone = true;
					break;
				}
				*s++ = c;
				if (c == '\n')
				{
					linedone = true;
					break;
				}
				if (c == '\r')
					saw_cr = true;
			}
			*s = '\0';
			/* EOF with empty line-so-far? */
			if (c == EOF && s == copybuf && firstload)
			{
				/*
				 * We are guessing a little bit as to the right line-ending
				 * here...
				 */
				if (saw_cr)
					PQputline(conn, "\\.\r\n");
				else
					PQputline(conn, "\\.\n");
				copydone = true;
				if (pset.cur_cmd_interactive)
					puts("\\.");
				break;
			}
			/* No, so pass the data to the backend */
			PQputline(conn, copybuf);
			/* Check for line consisting only of \. */
			if (firstload)
			{
				if (strcmp(copybuf, "\\.\n") == 0 ||
					strcmp(copybuf, "\\.\r\n") == 0)
				{
					copydone = true;
					break;
				}
				firstload = false;
			}
		}
		linecount++;
	}
	ret = !PQendcopy(conn);
	pset.lineno += linecount;
	return ret;
}