postgresql/src/bin/scripts/dropuser.c

178 lines
4.5 KiB
C
Raw Normal View History

/*-------------------------------------------------------------------------
*
* dropuser
*
* Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
2010-09-20 22:08:53 +02:00
* src/bin/scripts/dropuser.c
*
*-------------------------------------------------------------------------
*/
#include "postgres_fe.h"
#include "common.h"
#include "fe_utils/string_utils.h"
static void help(const char *progname);
int
main(int argc, char *argv[])
{
static int if_exists = 0;
static struct option long_options[] = {
{"host", required_argument, NULL, 'h'},
{"port", required_argument, NULL, 'p'},
{"username", required_argument, NULL, 'U'},
{"no-password", no_argument, NULL, 'w'},
{"password", no_argument, NULL, 'W'},
{"echo", no_argument, NULL, 'e'},
{"interactive", no_argument, NULL, 'i'},
{"if-exists", no_argument, &if_exists, 1},
{NULL, 0, NULL, 0}
};
const char *progname;
int optindex;
int c;
char *dropuser = NULL;
char *host = NULL;
char *port = NULL;
char *username = NULL;
enum trivalue prompt_password = TRI_DEFAULT;
bool echo = false;
bool interactive = false;
Simplify correct use of simple_prompt(). The previous API for this function had it returning a malloc'd string. That meant that callers had to check for NULL return, which few of them were doing, and it also meant that callers had to remember to free() the string later, which required extra logic in most cases. Instead, make simple_prompt() write into a buffer supplied by the caller. Anywhere that the maximum required input length is reasonably small, which is almost all of the callers, we can just use a local or static array as the buffer instead of dealing with malloc/free. A fair number of callers used "pointer == NULL" as a proxy for "haven't requested the password yet". Maintaining the same behavior requires adding a separate boolean flag for that, which adds back some of the complexity we save by removing free()s. Nonetheless, this nets out at a small reduction in overall code size, and considerably less code than we would have had if we'd added the missing NULL-return checks everywhere they were needed. In passing, clean up the API comment for simple_prompt() and get rid of a very-unnecessary malloc/free in its Windows code path. This is nominally a bug fix, but it does not seem worth back-patching, because the actual risk of an OOM failure in any of these places seems pretty tiny, and all of them are client-side not server-side anyway. This patch is by me, but it owes a great deal to Michael Paquier who identified the problem and drafted a patch for fixing it the other way. Discussion: <CAB7nPqRu07Ot6iht9i9KRfYLpDaF2ZuUv5y_+72uP23ZAGysRg@mail.gmail.com>
2016-08-30 23:02:02 +02:00
char dropuser_buf[128];
PQExpBufferData sql;
PGconn *conn;
PGresult *result;
progname = get_progname(argv[0]);
set_pglocale_pgservice(argv[0], PG_TEXTDOMAIN("pgscripts"));
handle_help_version_opts(argc, argv, "dropuser", help);
while ((c = getopt_long(argc, argv, "h:p:U:wWei", long_options, &optindex)) != -1)
{
switch (c)
{
case 'h':
host = pg_strdup(optarg);
break;
case 'p':
port = pg_strdup(optarg);
break;
case 'U':
username = pg_strdup(optarg);
break;
case 'w':
prompt_password = TRI_NO;
break;
case 'W':
prompt_password = TRI_YES;
break;
case 'e':
echo = true;
break;
case 'i':
interactive = true;
break;
case 0:
/* this covers the long options */
break;
default:
fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
exit(1);
}
}
switch (argc - optind)
{
case 0:
break;
case 1:
dropuser = argv[optind];
break;
default:
fprintf(stderr, _("%s: too many command-line arguments (first is \"%s\")\n"),
progname, argv[optind + 1]);
fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
exit(1);
}
if (dropuser == NULL)
{
if (interactive)
Simplify correct use of simple_prompt(). The previous API for this function had it returning a malloc'd string. That meant that callers had to check for NULL return, which few of them were doing, and it also meant that callers had to remember to free() the string later, which required extra logic in most cases. Instead, make simple_prompt() write into a buffer supplied by the caller. Anywhere that the maximum required input length is reasonably small, which is almost all of the callers, we can just use a local or static array as the buffer instead of dealing with malloc/free. A fair number of callers used "pointer == NULL" as a proxy for "haven't requested the password yet". Maintaining the same behavior requires adding a separate boolean flag for that, which adds back some of the complexity we save by removing free()s. Nonetheless, this nets out at a small reduction in overall code size, and considerably less code than we would have had if we'd added the missing NULL-return checks everywhere they were needed. In passing, clean up the API comment for simple_prompt() and get rid of a very-unnecessary malloc/free in its Windows code path. This is nominally a bug fix, but it does not seem worth back-patching, because the actual risk of an OOM failure in any of these places seems pretty tiny, and all of them are client-side not server-side anyway. This patch is by me, but it owes a great deal to Michael Paquier who identified the problem and drafted a patch for fixing it the other way. Discussion: <CAB7nPqRu07Ot6iht9i9KRfYLpDaF2ZuUv5y_+72uP23ZAGysRg@mail.gmail.com>
2016-08-30 23:02:02 +02:00
{
simple_prompt("Enter name of role to drop: ",
dropuser_buf, sizeof(dropuser_buf), true);
dropuser = dropuser_buf;
}
else
{
fprintf(stderr, _("%s: missing required argument role name\n"), progname);
fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
exit(1);
}
}
if (interactive)
{
printf(_("Role \"%s\" will be permanently removed.\n"), dropuser);
if (!yesno_prompt("Are you sure?"))
exit(0);
}
initPQExpBuffer(&sql);
appendPQExpBuffer(&sql, "DROP ROLE %s%s;",
(if_exists ? "IF EXISTS " : ""), fmtId(dropuser));
conn = connectDatabase("postgres", host, port, username, prompt_password,
progname, echo, false, false);
if (echo)
printf("%s\n", sql.data);
result = PQexec(conn, sql.data);
if (PQresultStatus(result) != PGRES_COMMAND_OK)
{
fprintf(stderr, _("%s: removal of role \"%s\" failed: %s"),
progname, dropuser, PQerrorMessage(conn));
PQfinish(conn);
exit(1);
}
PQclear(result);
PQfinish(conn);
exit(0);
}
static void
help(const char *progname)
{
2005-09-30 09:58:01 +02:00
printf(_("%s removes a PostgreSQL role.\n\n"), progname);
printf(_("Usage:\n"));
2005-09-30 09:58:01 +02:00
printf(_(" %s [OPTION]... [ROLENAME]\n"), progname);
printf(_("\nOptions:\n"));
printf(_(" -e, --echo show the commands being sent to the server\n"));
printf(_(" -i, --interactive prompt before deleting anything, and prompt for\n"
" role name if not specified\n"));
printf(_(" -V, --version output version information, then exit\n"));
printf(_(" --if-exists don't report error if user doesn't exist\n"));
printf(_(" -?, --help show this help, then exit\n"));
printf(_("\nConnection options:\n"));
printf(_(" -h, --host=HOSTNAME database server host or socket directory\n"));
printf(_(" -p, --port=PORT database server port\n"));
printf(_(" -U, --username=USERNAME user name to connect as (not the one to drop)\n"));
printf(_(" -w, --no-password never prompt for password\n"));
printf(_(" -W, --password force password prompt\n"));
printf(_("\nReport bugs to <pgsql-bugs@lists.postgresql.org>.\n"));
}