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postgresql/src/bin/psql/copy.c

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/*
* psql - the PostgreSQL interactive terminal
*
* Copyright (c) 2000-2009, PostgreSQL Global Development Group
*
* $PostgreSQL: pgsql/src/bin/psql/copy.c,v 1.82 2009/08/07 20:16:11 tgl Exp $
*/
#include "postgres_fe.h"
#include "copy.h"
#include <signal.h>
#include <sys/stat.h>
#ifndef WIN32
#include <unistd.h> /* for isatty */
#else
#include <io.h> /* I think */
#endif
#include "libpq-fe.h"
#include "pqexpbuffer.h"
#include "pqsignal.h"
#include "dumputils.h"
#include "settings.h"
#include "common.h"
#include "prompt.h"
#include "stringutils.h"
/*
* parse_slash_copy
* -- parses \copy command line
*
* The documented syntax is:
* \copy tablename [(columnlist)] from|to filename
* [ with ] [ binary ] [ oids ] [ delimiter [as] char ] [ null [as] string ]
* [ csv [ header ] [ quote [ AS ] string ] escape [as] string
* [ force not null column [, ...] | force quote column [, ...] | * ] ]
*
* \copy ( select stmt ) to filename
* [ with ] [ binary ] [ delimiter [as] char ] [ null [as] string ]
* [ csv [ header ] [ quote [ AS ] string ] escape [as] string
* [ force quote column [, ...] | * ] ]
*
* Force quote only applies for copy to; force not null only applies for
* copy from.
*
* table name can be double-quoted and can have a schema part.
* column names can be double-quoted.
* filename, char, and string can be single-quoted like SQL literals.
*
* returns a malloc'ed structure with the options, or NULL on parsing error
*/
struct copy_options
{
char *table;
char *column_list;
char *file; /* NULL = stdin/stdout */
bool psql_inout; /* true = use psql stdin/stdout */
bool from;
bool binary;
bool oids;
bool csv_mode;
bool header;
char *delim;
char *null;
char *quote;
char *escape;
char *force_quote_list;
char *force_notnull_list;
};
static void
free_copy_options(struct copy_options * ptr)
{
if (!ptr)
return;
free(ptr->table);
free(ptr->column_list);
free(ptr->file);
free(ptr->delim);
free(ptr->null);
free(ptr->quote);
free(ptr->escape);
free(ptr->force_quote_list);
free(ptr->force_notnull_list);
free(ptr);
}
/* concatenate "more" onto "var", freeing the original value of *var */
static void
xstrcat(char **var, const char *more)
{
char *newvar;
newvar = pg_malloc(strlen(*var) + strlen(more) + 1);
strcpy(newvar, *var);
strcat(newvar, more);
free(*var);
*var = newvar;
}
static struct copy_options *
parse_slash_copy(const char *args)
{
struct copy_options *result;
char *line;
char *token;
const char *whitespace = " \t\n\r";
char nonstd_backslash = standard_strings() ? 0 : '\\';
if (args)
line = pg_strdup(args);
else
{
psql_error("\\copy: arguments required\n");
return NULL;
}
result = pg_calloc(1, sizeof(struct copy_options));
token = strtokx(line, whitespace, ".,()", "\"",
0, false, false, pset.encoding);
if (!token)
goto error;
if (pg_strcasecmp(token, "binary") == 0)
{
result->binary = true;
token = strtokx(NULL, whitespace, ".,()", "\"",
0, false, false, pset.encoding);
if (!token)
goto error;
}
result->table = pg_strdup(token);
/* Handle COPY (SELECT) case */
if (token[0] == '(')
{
int parens = 1;
while (parens > 0)
{
token = strtokx(NULL, whitespace, ".,()", "\"'",
nonstd_backslash, true, false, pset.encoding);
if (!token)
goto error;
if (token[0] == '(')
parens++;
else if (token[0] == ')')
parens--;
xstrcat(&result->table, " ");
xstrcat(&result->table, token);
}
}
token = strtokx(NULL, whitespace, ".,()", "\"",
0, false, false, pset.encoding);
if (!token)
goto error;
/*
* strtokx() will not have returned a multi-character token starting with
* '.', so we don't need strcmp() here. Likewise for '(', etc, below.
*/
if (token[0] == '.')
{
/* handle schema . table */
xstrcat(&result->table, token);
token = strtokx(NULL, whitespace, ".,()", "\"",
0, false, false, pset.encoding);
if (!token)
goto error;
xstrcat(&result->table, token);
token = strtokx(NULL, whitespace, ".,()", "\"",
0, false, false, pset.encoding);
if (!token)
goto error;
}
if (token[0] == '(')
{
/* handle parenthesized column list */
result->column_list = pg_strdup(token);
for (;;)
{
token = strtokx(NULL, whitespace, ".,()", "\"",
0, false, false, pset.encoding);
if (!token || strchr(".,()", token[0]))
goto error;
xstrcat(&result->column_list, token);
token = strtokx(NULL, whitespace, ".,()", "\"",
0, false, false, pset.encoding);
if (!token)
goto error;
xstrcat(&result->column_list, token);
if (token[0] == ')')
break;
if (token[0] != ',')
goto error;
}
token = strtokx(NULL, whitespace, ".,()", "\"",
0, false, false, pset.encoding);
if (!token)
goto error;
}
if (pg_strcasecmp(token, "from") == 0)
result->from = true;
else if (pg_strcasecmp(token, "to") == 0)
result->from = false;
else
goto error;
token = strtokx(NULL, whitespace, NULL, "'",
0, false, true, pset.encoding);
if (!token)
goto error;
if (pg_strcasecmp(token, "stdin") == 0 ||
pg_strcasecmp(token, "stdout") == 0)
{
result->psql_inout = false;
result->file = NULL;
}
else if (pg_strcasecmp(token, "pstdin") == 0 ||
pg_strcasecmp(token, "pstdout") == 0)
{
result->psql_inout = true;
result->file = NULL;
}
else
{
result->psql_inout = false;
result->file = pg_strdup(token);
expand_tilde(&result->file);
}
token = strtokx(NULL, whitespace, NULL, NULL,
0, false, false, pset.encoding);
if (token)
{
/*
* WITH is optional. Also, the backend will allow WITH followed by
* nothing, so we do too.
*/
if (pg_strcasecmp(token, "with") == 0)
token = strtokx(NULL, whitespace, NULL, NULL,
0, false, false, pset.encoding);
while (token)
{
bool fetch_next;
fetch_next = true;
if (pg_strcasecmp(token, "oids") == 0)
result->oids = true;
else if (pg_strcasecmp(token, "binary") == 0)
result->binary = true;
else if (pg_strcasecmp(token, "csv") == 0)
result->csv_mode = true;
else if (pg_strcasecmp(token, "header") == 0)
result->header = true;
else if (pg_strcasecmp(token, "delimiter") == 0)
{
if (result->delim)
goto error;
token = strtokx(NULL, whitespace, NULL, "'",
nonstd_backslash, true, false, pset.encoding);
if (token && pg_strcasecmp(token, "as") == 0)
token = strtokx(NULL, whitespace, NULL, "'",
nonstd_backslash, true, false, pset.encoding);
if (token)
result->delim = pg_strdup(token);
else
goto error;
}
else if (pg_strcasecmp(token, "null") == 0)
{
if (result->null)
goto error;
token = strtokx(NULL, whitespace, NULL, "'",
nonstd_backslash, true, false, pset.encoding);
if (token && pg_strcasecmp(token, "as") == 0)
token = strtokx(NULL, whitespace, NULL, "'",
nonstd_backslash, true, false, pset.encoding);
if (token)
result->null = pg_strdup(token);
else
goto error;
}
else if (pg_strcasecmp(token, "quote") == 0)
{
if (result->quote)
goto error;
token = strtokx(NULL, whitespace, NULL, "'",
nonstd_backslash, true, false, pset.encoding);
if (token && pg_strcasecmp(token, "as") == 0)
token = strtokx(NULL, whitespace, NULL, "'",
nonstd_backslash, true, false, pset.encoding);
if (token)
result->quote = pg_strdup(token);
else
goto error;
}
else if (pg_strcasecmp(token, "escape") == 0)
{
if (result->escape)
goto error;
token = strtokx(NULL, whitespace, NULL, "'",
nonstd_backslash, true, false, pset.encoding);
if (token && pg_strcasecmp(token, "as") == 0)
token = strtokx(NULL, whitespace, NULL, "'",
nonstd_backslash, true, false, pset.encoding);
if (token)
result->escape = pg_strdup(token);
else
goto error;
}
else if (pg_strcasecmp(token, "force") == 0)
{
token = strtokx(NULL, whitespace, ",", "\"",
0, false, false, pset.encoding);
if (pg_strcasecmp(token, "quote") == 0)
{
if (result->force_quote_list)
goto error;
/* handle column list */
fetch_next = false;
for (;;)
{
token = strtokx(NULL, whitespace, ",", "\"",
0, false, false, pset.encoding);
if (!token || strchr(",", token[0]))
goto error;
if (!result->force_quote_list)
result->force_quote_list = pg_strdup(token);
else
xstrcat(&result->force_quote_list, token);
token = strtokx(NULL, whitespace, ",", "\"",
0, false, false, pset.encoding);
if (!token || token[0] != ',')
break;
xstrcat(&result->force_quote_list, token);
}
}
else if (pg_strcasecmp(token, "not") == 0)
{
if (result->force_notnull_list)
goto error;
token = strtokx(NULL, whitespace, ",", "\"",
0, false, false, pset.encoding);
if (pg_strcasecmp(token, "null") != 0)
goto error;
/* handle column list */
fetch_next = false;
for (;;)
{
token = strtokx(NULL, whitespace, ",", "\"",
0, false, 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, 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, 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;
}
/*
* Handle one of the "string" options of COPY. If the user gave a quoted
* string, pass it to the backend as-is; if it wasn't quoted then quote
* and escape it.
*/
static void
emit_copy_option(PQExpBuffer query, const char *keyword, const char *option)
{
appendPQExpBufferStr(query, keyword);
if (option[0] == '\'' ||
((option[0] == 'E' || option[0] == 'e') && option[1] == '\''))
appendPQExpBufferStr(query, option);
else
appendStringLiteralConn(query, option, pset.db);
}
/*
* 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 ");
appendPQExpBuffer(&query, "%s ", options->table);
if (options->column_list)
appendPQExpBuffer(&query, "%s ", options->column_list);
if (options->from)
appendPQExpBuffer(&query, "FROM STDIN");
else
appendPQExpBuffer(&query, "TO STDOUT");
if (options->binary)
appendPQExpBuffer(&query, " BINARY ");
if (options->oids)
appendPQExpBuffer(&query, " OIDS ");
if (options->delim)
emit_copy_option(&query, " DELIMITER ", options->delim);
if (options->null)
emit_copy_option(&query, " NULL AS ", options->null);
if (options->csv_mode)
appendPQExpBuffer(&query, " CSV");
if (options->header)
appendPQExpBuffer(&query, " HEADER");
if (options->quote)
emit_copy_option(&query, " QUOTE AS ", options->quote);
if (options->escape)
emit_copy_option(&query, " ESCAPE AS ", 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,
options->binary ? PG_BINARY_W : "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:
SetCancelConn();
success = handleCopyOut(pset.db, copystream);
ResetCancelConn();
break;
case PGRES_COPY_IN:
SetCancelConn();
success = handleCopyIn(pset.db, copystream,
PQbinaryTuples(result));
ResetCancelConn();
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));
break;
}
PQclear(result);
/*
* Make sure we have pumped libpq dry of results; else it may still be in
* ASYNC_BUSY state, leading to false readings in, eg, get_prompt().
*/
while ((result = PQgetResult(pset.db)) != NULL)
{
success = false;
psql_error("\\copy: unexpected response (%d)\n",
PQresultStatus(result));
/* if still in COPY IN state, try to get out of it */
if (PQresultStatus(result) == PGRES_COPY_IN)
PQputCopyEnd(pset.db, _("trying to exit copy mode"));
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;
}
/*
* Functions for handling COPY IN/OUT data transfer.
*
* If you want to use COPY TO STDOUT/FROM STDIN in your application,
* this is the code to steal ;)
*/
/*
* handleCopyOut
* receives data as a result of a COPY ... TO STDOUT command
*
* conn should be a database connection that you just issued COPY TO on
* and got back a PGRES_COPY_OUT result.
* copystream is the file stream for the data to go to.
*
* result is true if successful, false if not.
*/
bool
handleCopyOut(PGconn *conn, FILE *copystream)
{
bool OK = true;
char *buf;
int ret;
PGresult *res;
for (;;)
{
ret = PQgetCopyData(conn, &buf, 0);
if (ret < 0)
break; /* done or error */
if (buf)
{
if (fwrite(buf, 1, ret, copystream) != ret)
{
if (OK) /* complain only once, keep reading data */
psql_error("could not write COPY data: %s\n",
strerror(errno));
OK = false;
}
PQfreemem(buf);
}
}
if (OK && fflush(copystream))
{
psql_error("could not write COPY data: %s\n",
strerror(errno));
OK = false;
}
if (ret == -2)
{
psql_error("COPY data transfer failed: %s", PQerrorMessage(conn));
OK = false;
}
/* Check command status and return to normal libpq state */
res = PQgetResult(conn);
if (PQresultStatus(res) != PGRES_COMMAND_OK)
{
psql_error("%s", PQerrorMessage(conn));
OK = false;
}
PQclear(res);
return OK;
}
/*
* handleCopyIn
* sends data to complete a COPY ... FROM STDIN command
*
* conn should be a database connection that you just issued COPY FROM on
* and got back a PGRES_COPY_IN result.
* copystream is the file stream to read the data from.
* isbinary can be set from PQbinaryTuples().
*
* result is true if successful, false if not.
*/
/* read chunk size for COPY IN - size is not critical */
#define COPYBUFSIZ 8192
bool
handleCopyIn(PGconn *conn, FILE *copystream, bool isbinary)
{
bool OK;
const char *prompt;
char buf[COPYBUFSIZ];
PGresult *res;
/*
* Establish longjmp destination for exiting from wait-for-input. (This is
* only effective while sigint_interrupt_enabled is TRUE.)
*/
if (sigsetjmp(sigint_interrupt_jmp, 1) != 0)
{
/* got here with longjmp */
/* Terminate data transfer */
PQputCopyEnd(conn, _("canceled by user"));
/* Check command status and return to normal libpq state */
res = PQgetResult(conn);
if (PQresultStatus(res) != PGRES_COMMAND_OK)
psql_error("%s", PQerrorMessage(conn));
PQclear(res);
return false;
}
/* Prompt if interactive input */
if (isatty(fileno(copystream)))
{
if (!pset.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;
OK = true;
if (isbinary)
{
/* interactive input probably silly, but give one prompt anyway */
if (prompt)
{
fputs(prompt, stdout);
fflush(stdout);
}
for (;;)
{
int buflen;
/* enable longjmp while waiting for input */
sigint_interrupt_enabled = true;
buflen = fread(buf, 1, COPYBUFSIZ, copystream);
sigint_interrupt_enabled = false;
if (buflen <= 0)
break;
if (PQputCopyData(conn, buf, buflen) <= 0)
{
OK = false;
break;
}
}
}
else
{
bool copydone = false;
while (!copydone)
{ /* for each input line ... */
bool firstload;
bool linedone;
if (prompt)
{
fputs(prompt, stdout);
fflush(stdout);
}
firstload = true;
linedone = false;
while (!linedone)
{ /* for each bufferload in line ... */
int linelen;
char *fgresult;
/* enable longjmp while waiting for input */
sigint_interrupt_enabled = true;
fgresult = fgets(buf, sizeof(buf), copystream);
sigint_interrupt_enabled = false;
if (!fgresult)
{
copydone = true;
break;
}
linelen = strlen(buf);
/* current line is done? */
if (linelen > 0 && buf[linelen - 1] == '\n')
linedone = true;
/* check for EOF marker, but not on a partial line */
if (firstload)
{
if (strcmp(buf, "\\.\n") == 0 ||
strcmp(buf, "\\.\r\n") == 0)
{
copydone = true;
break;
}
firstload = false;
}
if (PQputCopyData(conn, buf, linelen) <= 0)
{
OK = false;
copydone = true;
break;
}
}
pset.lineno++;
}
}
/* Check for read error */
if (ferror(copystream))
OK = false;
/* Terminate data transfer */
if (PQputCopyEnd(conn,
OK ? NULL : _("aborted because of read failure")) <= 0)
OK = false;
/* Check command status and return to normal libpq state */
res = PQgetResult(conn);
if (PQresultStatus(res) != PGRES_COMMAND_OK)
{
psql_error("%s", PQerrorMessage(conn));
OK = false;
}
PQclear(res);
return OK;
}
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