external/ibm-public/postfix/dist/src/util/fullname.c

   1 /*      $NetBSD$        */
   2
   3 /*++
   4 /* NAME
   5 /*      fullname 3
   6 /* SUMMARY
   7 /*      lookup personal name of invoking user
   8 /* SYNOPSIS
   9 /*      #include <fullname.h>
  10 /*
  11 /*      const char *fullname()
  12 /* DESCRIPTION
  13 /*      fullname() looks up the personal name of the invoking user.
  14 /*      The result is volatile. Make a copy if it is to be used for
  15 /*      an appreciable amount of time.
  16 /*
  17 /*      On UNIX systems, fullname() first tries to use the NAME environment
  18 /*      variable, provided that the environment can be trusted.
  19 /*      If that fails, fullname() extracts the username from the GECOS
  20 /*      field of the user's password-file entry, replacing any occurrence
  21 /*      of "&" by the login name, first letter capitalized.
  22 /*
  23 /*      A null result means that no full name information was found.
  24 /* SEE ALSO
  25 /*      safe_getenv(3) safe getenv() interface
  26 /* LICENSE
  27 /* .ad
  28 /* .fi
  29 /*      The Secure Mailer license must be distributed with this software.
  30 /* AUTHOR(S)
  31 /*      Wietse Venema
  32 /*      IBM T.J. Watson Research
  33 /*      P.O. Box 704
  34 /*      Yorktown Heights, NY 10598, USA
  35 /*--*/
  36
  37 /* System library. */
  38
  39 #include <sys_defs.h>
  40 #include <unistd.h>
  41 #include <pwd.h>
  42 #include <ctype.h>
  43 #include <stdlib.h>
  44 #include <string.h>
  45
  46 /* Utility library. */
  47
  48 #include "vstring.h"
  49 #include "safe.h"
  50 #include "fullname.h"
  51
  52 /* fullname - get name of user */
  53
  54 const char *fullname(void)
  55 {
  56     static VSTRING *result;
  57     char   *cp;
  58     int     ch;
  59     uid_t   uid;
  60     struct passwd *pwd;
  61
  62     if (result == 0)
  63         result = vstring_alloc(10);
  64
  65     /*
  66      * Try the environment.
  67      */
  68     if ((cp = safe_getenv("NAME")) != 0)
  69         return (vstring_str(vstring_strcpy(result, cp)));
  70
  71     /*
  72      * Try the password file database.
  73      */
  74     uid = getuid();
  75     if ((pwd = getpwuid(uid)) == 0)
  76         return (0);
  77
  78     /*
  79      * Replace all `&' characters by the login name of this user, first
  80      * letter capitalized. Although the full name comes from the protected
  81      * password file, the actual data is specified by the user so we should
  82      * not trust its sanity.
  83      */
  84     VSTRING_RESET(result);
  85     for (cp = pwd->pw_gecos; (ch = *(unsigned char *) cp) != 0; cp++) {
  86         if (ch == ',' || ch == ';' || ch == '%')
  87             break;
  88         if (ch == '&') {
  89             if (pwd->pw_name[0]) {
  90                 VSTRING_ADDCH(result, TOUPPER(pwd->pw_name[0]));
  91                 vstring_strcat(result, pwd->pw_name + 1);
  92             }
  93         } else {
  94             VSTRING_ADDCH(result, ch);
  95         }
  96     }
  97     VSTRING_TERMINATE(result);
  98     return (vstring_str(result));
  99 }
 100
 101 #ifdef TEST
 102
 103 #include <stdio.h>
 104
 105 int     main(int unused_argc, char **unused_argv)
 106 {
 107     const char *cp = fullname();
 108
 109     printf("%s\n", cp ? cp : "null!");
 110     return (0);
 111 }
 112
 113 #endif