2.9BSD - /usr/src/ucb/oldcsh/getpwent.c

   1: /*
   2:  * Modified version of getpwent which doesn't use stdio.
   3:  * This is done to keep it (and hence csh) small at a small
   4:  * cost in speed.
   5:  *
   6:  * This version also uses the UCB hashed password file if whoami.h
   7:  * indicates that UCB_PWHASH is available.  In any case if it fails
   8:  * it tries the regular linear search.
   9:  *
  10:  * Define BBGETPW (Bare Bones GETPW) if all you are interested in is
  11:  * the name, uid, and directory fields.  This will make getpwent smaller
  12:  * and a bit faster and is useful for things like csh.
  13:  */
  14: #define BBGETPW
  15: 
  16: #include <pwd.h>
  17: #include <whoami.h>
  18: 
  19: #ifdef UCB_PWHASH
  20: #define pwf _pw_file                /* unlikely symbol name */
  21: #endif
  22: 
  23: /*
  24:  * predefined strings
  25:  */
  26: #undef  BUFSIZ
  27: #define BUFSIZ 160
  28: 
  29: int pwf = -1;           /* password file pointer */
  30: 
  31: char    line[BUFSIZ+1];         /* input buffer */
  32: 
  33: struct passwd   passwd;         /* password entry */
  34: 
  35: setpwent()
  36: {
  37:     if( pwf == -1 )
  38:         pwf = open( "/etc/passwd", 0 );
  39:     else
  40:         lseek(pwf, 0l, 0);
  41: }
  42: 
  43: endpwent()
  44: {
  45:     if( pwf != -1 ){
  46:         close( pwf );
  47:         pwf = -1;
  48:     }
  49: }
  50: 
  51: static char *
  52: pwskip(p)
  53: register char *p;
  54: {
  55:     while( *p && *p != ':' )
  56:         ++p;
  57:     if( *p ) *p++ = 0;
  58:     return(p);
  59: }
  60: 
  61: struct passwd *
  62: getpwent()
  63: {
  64:     register char *p, *q;
  65:     register int i, j;
  66: 
  67:     if (pwf == -1) {
  68:         if( (pwf = open( "/etc/passwd", 0 )) == -1 )
  69:             return(0);
  70:     }
  71:     i = read(pwf, line, BUFSIZ);
  72:     for (j = 0; j < i; j++)
  73:         if (line[j] == '\n')
  74:             break;
  75:     if (j >= i)
  76:         return(0);
  77:     line[++j] = 0;
  78:     lseek(pwf, (long) (j - i), 1);
  79:     p = line;
  80:     passwd.pw_name = p;
  81:     p = pwskip(p);
  82: #ifndef BBGETPW
  83:     passwd.pw_passwd = p;
  84: #endif
  85:     p = pwskip(p);
  86:     passwd.pw_uid = atoi(p);
  87:     p = pwskip(p);
  88: #ifndef BBGETPW
  89:     passwd.pw_gid = atoi(p);
  90:     passwd.pw_quota = 0;
  91:     passwd.pw_comment = "";
  92: #endif
  93:     p = pwskip(p);
  94: #ifndef BBGETPW
  95:     passwd.pw_gecos = p;
  96: #endif
  97:     p = pwskip(p);
  98:     passwd.pw_dir = p;
  99:     p = pwskip(p);
 100: #ifndef BBGETPW
 101:     passwd.pw_shell = p;
 102:     while(*p && *p != '\n') p++;
 103:     *p = '\0';
 104: #endif
 105:     return(&passwd);
 106: }

Defined functions

Defined variables

Defined macros