src/port/user.c

   1 /*-------------------------------------------------------------------------
   2  *
   3  * user.c
   4  *
   5  *                Wrapper functions for user and home directory lookup.
   6  *
   7  * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
   8  *
   9  * src/port/user.c
  10  *
  11  *-------------------------------------------------------------------------
  12  */
  13
  14 #include "c.h"
  15
  16 #include <pwd.h>
  17
  18 #ifndef WIN32
  19
  20 /*
  21  * pg_get_user_name - get the name of the user with the given ID
  22  *
  23  * On success, the user name is returned into the buffer (of size buflen),
  24  * and "true" is returned.  On failure, a localized error message is
  25  * returned into the buffer, and "false" is returned.
  26  */
  27 bool
  28 pg_get_user_name(uid_t user_id, char *buffer, size_t buflen)
  29 {
  30         char            pwdbuf[BUFSIZ];
  31         struct passwd pwdstr;
  32         struct passwd *pw = NULL;
  33         int                     pwerr;
  34
  35         pwerr = getpwuid_r(user_id, &pwdstr, pwdbuf, sizeof(pwdbuf), &pw);
  36         if (pw != NULL)
  37         {
  38                 strlcpy(buffer, pw->pw_name, buflen);
  39                 return true;
  40         }
  41         if (pwerr != 0)
  42                 snprintf(buffer, buflen,
  43                                  _("could not look up local user ID %d: %s"),
  44                                  (int) user_id,
  45                                  strerror_r(pwerr, pwdbuf, sizeof(pwdbuf)));
  46         else
  47                 snprintf(buffer, buflen,
  48                                  _("local user with ID %d does not exist"),
  49                                  (int) user_id);
  50         return false;
  51 }
  52
  53 /*
  54  * pg_get_user_home_dir - get the home directory of the user with the given ID
  55  *
  56  * On success, the directory path is returned into the buffer (of size buflen),
  57  * and "true" is returned.  On failure, a localized error message is
  58  * returned into the buffer, and "false" is returned.
  59  *
  60  * Note that this does not incorporate the common behavior of checking
  61  * $HOME first, since it's independent of which user_id is queried.
  62  */
  63 bool
  64 pg_get_user_home_dir(uid_t user_id, char *buffer, size_t buflen)
  65 {
  66         char            pwdbuf[BUFSIZ];
  67         struct passwd pwdstr;
  68         struct passwd *pw = NULL;
  69         int                     pwerr;
  70
  71         pwerr = getpwuid_r(user_id, &pwdstr, pwdbuf, sizeof(pwdbuf), &pw);
  72         if (pw != NULL)
  73         {
  74                 strlcpy(buffer, pw->pw_dir, buflen);
  75                 return true;
  76         }
  77         if (pwerr != 0)
  78                 snprintf(buffer, buflen,
  79                                  _("could not look up local user ID %d: %s"),
  80                                  (int) user_id,
  81                                  strerror_r(pwerr, pwdbuf, sizeof(pwdbuf)));
  82         else
  83                 snprintf(buffer, buflen,
  84                                  _("local user with ID %d does not exist"),
  85                                  (int) user_id);
  86         return false;
  87 }
  88
  89 #endif                                                  /* !WIN32 */