Datum
pg_file_unlink(PG_FUNCTION_ARGS)
{
char *filename;
requireSuperuser();
filename = convert_and_check_filename(PG_GETARG_TEXT_PP(0), false);
if (access(filename, W_OK) < 0)
{
if (errno == ENOENT)
PG_RETURN_BOOL(false);
else
ereport(ERROR,
(errcode_for_file_access(),
errmsg("file \"%s\" is not accessible: %m", filename)));
}
if (unlink(filename) < 0)
{
ereport(WARNING,
(errcode_for_file_access(),
errmsg("could not unlink file \"%s\": %m", filename)));
PG_RETURN_BOOL(false);
}
PG_RETURN_BOOL(true);
}
Datum
pg_file_write(PG_FUNCTION_ARGS)
{
FILE *f;
char *filename;
text *data;
int64 count = 0;
requireSuperuser();
filename = convert_and_check_filename(PG_GETARG_TEXT_P(0));
data = PG_GETARG_TEXT_P(1);
if (!PG_GETARG_BOOL(2))
{
struct stat fst;
if (stat(filename, &fst) >= 0)
ereport(ERROR,
(ERRCODE_DUPLICATE_FILE,
errmsg("file \"%s\" exists", filename)));
f = fopen(filename, "wb");
}
else
f = fopen(filename, "ab");
if (!f)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not open file \"%s\" for writing: %m",
filename)));
if (VARSIZE(data) != 0)
{
count = fwrite(VARDATA(data), 1, VARSIZE(data) - VARHDRSZ, f);
if (count != VARSIZE(data) - VARHDRSZ)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not write file \"%s\": %m", filename)));
}
fclose(f);
PG_RETURN_INT64(count);
}
Datum
pg_file_length(PG_FUNCTION_ARGS)
{
text *filename_t = PG_GETARG_TEXT_P(0);
char *filename;
struct stat fst;
requireSuperuser();
filename = convert_and_check_filename(filename_t);
if (stat(filename, &fst) < 0)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not stat file \"%s\": %m", filename)));
PG_RETURN_INT64((int64) fst.st_size);
}
Datum
pg_file_rename(PG_FUNCTION_ARGS)
{
char *fn1,
*fn2,
*fn3;
int rc;
requireSuperuser();
if (PG_ARGISNULL(0) || PG_ARGISNULL(1))
PG_RETURN_NULL();
fn1 = convert_and_check_filename(PG_GETARG_TEXT_PP(0), false);
fn2 = convert_and_check_filename(PG_GETARG_TEXT_PP(1), false);
if (PG_ARGISNULL(2))
fn3 = 0;
else
fn3 = convert_and_check_filename(PG_GETARG_TEXT_PP(2), false);
if (access(fn1, W_OK) < 0)
{
ereport(WARNING,
(errcode_for_file_access(),
errmsg("file \"%s\" is not accessible: %m", fn1)));
PG_RETURN_BOOL(false);
}
if (fn3 && access(fn2, W_OK) < 0)
{
ereport(WARNING,
(errcode_for_file_access(),
errmsg("file \"%s\" is not accessible: %m", fn2)));
PG_RETURN_BOOL(false);
}
rc = access(fn3 ? fn3 : fn2, 2);
if (rc >= 0 || errno != ENOENT)
{
ereport(ERROR,
(ERRCODE_DUPLICATE_FILE,
errmsg("cannot rename to target file \"%s\"",
fn3 ? fn3 : fn2)));
}
if (fn3)
{
if (rename(fn2, fn3) != 0)
{
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not rename \"%s\" to \"%s\": %m",
fn2, fn3)));
}
if (rename(fn1, fn2) != 0)
{
ereport(WARNING,
(errcode_for_file_access(),
errmsg("could not rename \"%s\" to \"%s\": %m",
fn1, fn2)));
if (rename(fn3, fn2) != 0)
{
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not rename \"%s\" back to \"%s\": %m",
fn3, fn2)));
}
else
{
ereport(ERROR,
(ERRCODE_UNDEFINED_FILE,
errmsg("renaming \"%s\" to \"%s\" was reverted",
fn2, fn3)));
}
}
}
else if (rename(fn1, fn2) != 0)
{
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not rename \"%s\" to \"%s\": %m", fn1, fn2)));
}
PG_RETURN_BOOL(true);
}