postgresql/src/bin/scripts/dropuser.c

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/*-------------------------------------------------------------------------
*
* dropuser
*
* Portions Copyright (c) 1996-2020, 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 "common/logging.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;
Unified logging system for command-line programs This unifies the various ad hoc logging (message printing, error printing) systems used throughout the command-line programs. Features: - Program name is automatically prefixed. - Message string does not end with newline. This removes a common source of inconsistencies and omissions. - Additionally, a final newline is automatically stripped, simplifying use of PQerrorMessage() etc., another common source of mistakes. - I converted error message strings to use %m where possible. - As a result of the above several points, more translatable message strings can be shared between different components and between frontends and backend, without gratuitous punctuation or whitespace differences. - There is support for setting a "log level". This is not meant to be user-facing, but can be used internally to implement debug or verbose modes. - Lazy argument evaluation, so no significant overhead if logging at some level is disabled. - Some color in the messages, similar to gcc and clang. Set PG_COLOR=auto to try it out. Some colors are predefined, but can be customized by setting PG_COLORS. - Common files (common/, fe_utils/, etc.) can handle logging much more simply by just using one API without worrying too much about the context of the calling program, requiring callbacks, or having to pass "progname" around everywhere. - Some programs called setvbuf() to make sure that stderr is unbuffered, even on Windows. But not all programs did that. This is now done centrally. Soft goals: - Reduces vertical space use and visual complexity of error reporting in the source code. - Encourages more deliberate classification of messages. For example, in some cases it wasn't clear without analyzing the surrounding code whether a message was meant as an error or just an info. - Concepts and terms are vaguely aligned with popular logging frameworks such as log4j and Python logging. This is all just about printing stuff out. Nothing affects program flow (e.g., fatal exits). The uses are just too varied to do that. Some existing code had wrappers that do some kind of print-and-exit, and I adapted those. I tried to keep the output mostly the same, but there is a lot of historical baggage to unwind and special cases to consider, and I might not always have succeeded. One significant change is that pg_rewind used to write all error messages to stdout. That is now changed to stderr. Reviewed-by: Donald Dong <xdong@csumb.edu> Reviewed-by: Arthur Zakirov <a.zakirov@postgrespro.ru> Discussion: https://www.postgresql.org/message-id/flat/6a609b43-4f57-7348-6480-bd022f924310@2ndquadrant.com
2019-04-01 14:24:37 +02:00
pg_logging_init(argv[0]);
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:
Unified logging system for command-line programs This unifies the various ad hoc logging (message printing, error printing) systems used throughout the command-line programs. Features: - Program name is automatically prefixed. - Message string does not end with newline. This removes a common source of inconsistencies and omissions. - Additionally, a final newline is automatically stripped, simplifying use of PQerrorMessage() etc., another common source of mistakes. - I converted error message strings to use %m where possible. - As a result of the above several points, more translatable message strings can be shared between different components and between frontends and backend, without gratuitous punctuation or whitespace differences. - There is support for setting a "log level". This is not meant to be user-facing, but can be used internally to implement debug or verbose modes. - Lazy argument evaluation, so no significant overhead if logging at some level is disabled. - Some color in the messages, similar to gcc and clang. Set PG_COLOR=auto to try it out. Some colors are predefined, but can be customized by setting PG_COLORS. - Common files (common/, fe_utils/, etc.) can handle logging much more simply by just using one API without worrying too much about the context of the calling program, requiring callbacks, or having to pass "progname" around everywhere. - Some programs called setvbuf() to make sure that stderr is unbuffered, even on Windows. But not all programs did that. This is now done centrally. Soft goals: - Reduces vertical space use and visual complexity of error reporting in the source code. - Encourages more deliberate classification of messages. For example, in some cases it wasn't clear without analyzing the surrounding code whether a message was meant as an error or just an info. - Concepts and terms are vaguely aligned with popular logging frameworks such as log4j and Python logging. This is all just about printing stuff out. Nothing affects program flow (e.g., fatal exits). The uses are just too varied to do that. Some existing code had wrappers that do some kind of print-and-exit, and I adapted those. I tried to keep the output mostly the same, but there is a lot of historical baggage to unwind and special cases to consider, and I might not always have succeeded. One significant change is that pg_rewind used to write all error messages to stdout. That is now changed to stderr. Reviewed-by: Donald Dong <xdong@csumb.edu> Reviewed-by: Arthur Zakirov <a.zakirov@postgrespro.ru> Discussion: https://www.postgresql.org/message-id/flat/6a609b43-4f57-7348-6480-bd022f924310@2ndquadrant.com
2019-04-01 14:24:37 +02:00
pg_log_error("too many command-line arguments (first is \"%s\")",
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
{
Unified logging system for command-line programs This unifies the various ad hoc logging (message printing, error printing) systems used throughout the command-line programs. Features: - Program name is automatically prefixed. - Message string does not end with newline. This removes a common source of inconsistencies and omissions. - Additionally, a final newline is automatically stripped, simplifying use of PQerrorMessage() etc., another common source of mistakes. - I converted error message strings to use %m where possible. - As a result of the above several points, more translatable message strings can be shared between different components and between frontends and backend, without gratuitous punctuation or whitespace differences. - There is support for setting a "log level". This is not meant to be user-facing, but can be used internally to implement debug or verbose modes. - Lazy argument evaluation, so no significant overhead if logging at some level is disabled. - Some color in the messages, similar to gcc and clang. Set PG_COLOR=auto to try it out. Some colors are predefined, but can be customized by setting PG_COLORS. - Common files (common/, fe_utils/, etc.) can handle logging much more simply by just using one API without worrying too much about the context of the calling program, requiring callbacks, or having to pass "progname" around everywhere. - Some programs called setvbuf() to make sure that stderr is unbuffered, even on Windows. But not all programs did that. This is now done centrally. Soft goals: - Reduces vertical space use and visual complexity of error reporting in the source code. - Encourages more deliberate classification of messages. For example, in some cases it wasn't clear without analyzing the surrounding code whether a message was meant as an error or just an info. - Concepts and terms are vaguely aligned with popular logging frameworks such as log4j and Python logging. This is all just about printing stuff out. Nothing affects program flow (e.g., fatal exits). The uses are just too varied to do that. Some existing code had wrappers that do some kind of print-and-exit, and I adapted those. I tried to keep the output mostly the same, but there is a lot of historical baggage to unwind and special cases to consider, and I might not always have succeeded. One significant change is that pg_rewind used to write all error messages to stdout. That is now changed to stderr. Reviewed-by: Donald Dong <xdong@csumb.edu> Reviewed-by: Arthur Zakirov <a.zakirov@postgrespro.ru> Discussion: https://www.postgresql.org/message-id/flat/6a609b43-4f57-7348-6480-bd022f924310@2ndquadrant.com
2019-04-01 14:24:37 +02:00
pg_log_error("missing required argument role name");
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)
{
Unified logging system for command-line programs This unifies the various ad hoc logging (message printing, error printing) systems used throughout the command-line programs. Features: - Program name is automatically prefixed. - Message string does not end with newline. This removes a common source of inconsistencies and omissions. - Additionally, a final newline is automatically stripped, simplifying use of PQerrorMessage() etc., another common source of mistakes. - I converted error message strings to use %m where possible. - As a result of the above several points, more translatable message strings can be shared between different components and between frontends and backend, without gratuitous punctuation or whitespace differences. - There is support for setting a "log level". This is not meant to be user-facing, but can be used internally to implement debug or verbose modes. - Lazy argument evaluation, so no significant overhead if logging at some level is disabled. - Some color in the messages, similar to gcc and clang. Set PG_COLOR=auto to try it out. Some colors are predefined, but can be customized by setting PG_COLORS. - Common files (common/, fe_utils/, etc.) can handle logging much more simply by just using one API without worrying too much about the context of the calling program, requiring callbacks, or having to pass "progname" around everywhere. - Some programs called setvbuf() to make sure that stderr is unbuffered, even on Windows. But not all programs did that. This is now done centrally. Soft goals: - Reduces vertical space use and visual complexity of error reporting in the source code. - Encourages more deliberate classification of messages. For example, in some cases it wasn't clear without analyzing the surrounding code whether a message was meant as an error or just an info. - Concepts and terms are vaguely aligned with popular logging frameworks such as log4j and Python logging. This is all just about printing stuff out. Nothing affects program flow (e.g., fatal exits). The uses are just too varied to do that. Some existing code had wrappers that do some kind of print-and-exit, and I adapted those. I tried to keep the output mostly the same, but there is a lot of historical baggage to unwind and special cases to consider, and I might not always have succeeded. One significant change is that pg_rewind used to write all error messages to stdout. That is now changed to stderr. Reviewed-by: Donald Dong <xdong@csumb.edu> Reviewed-by: Arthur Zakirov <a.zakirov@postgrespro.ru> Discussion: https://www.postgresql.org/message-id/flat/6a609b43-4f57-7348-6480-bd022f924310@2ndquadrant.com
2019-04-01 14:24:37 +02:00
pg_log_error("removal of role \"%s\" failed: %s",
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 <%s>.\n"), PACKAGE_BUGREPORT);
printf(_("%s home page: <%s>\n"), PACKAGE_NAME, PACKAGE_URL);
}