2.11BSD#431 - /usr/src/lib/libc/gen/nlist.c

   1: /*
   2:  * Copyright (c) 1989 The Regents of the University of California.
   3:  * All rights reserved.
   4:  *
   5:  * Redistribution and use in source and binary forms are permitted
   6:  * provided that: (1) source distributions retain this entire copyright
   7:  * notice and comment, and (2) distributions including binaries display
   8:  * the following acknowledgement:  ``This product includes software
   9:  * developed by the University of California, Berkeley and its contributors''
  10:  * in the documentation or other materials provided with the distribution
  11:  * and in all advertising materials mentioning features or use of this
  12:  * software. Neither the name of the University nor the names of its
  13:  * contributors may be used to endorse or promote products derived
  14:  * from this software without specific prior written permission.
  15:  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
  16:  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  17:  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  18:  */
  19: 
  20: #if defined(LIBC_SCCS) && !defined(lint)
  21: static char sccsid[] = "@(#)nlist.c	5.7.1 (2.11BSD GTE) 12/31/93";
  22: #endif
  23: 
  24: #include <sys/types.h>
  25: #include <sys/file.h>
  26: #include <a.out.h>
  27: #include <stdio.h>
  28: 
  29: typedef struct nlist NLIST;
  30: #define _strx   n_un.n_strx
  31: #define _name   n_un.n_name
  32: #define ISVALID(p)  (p->_name && p->_name[0])
  33: 
  34: nlist(name, list)
  35:     char *name;
  36:     NLIST *list;
  37: {
  38:     register NLIST *p, *s;
  39:     struct xexec ebuf;
  40:     FILE *fstr, *fsym;
  41:     NLIST nbuf;
  42:     off_t strings_offset, symbol_offset, symbol_size, lseek();
  43:     int entries, len, maxlen;
  44:     char sbuf[128];
  45: 
  46:     entries = -1;
  47: 
  48:     if (!(fsym = fopen(name, "r")))
  49:         return(-1);
  50:     if (fread((char *)&ebuf, 1, sizeof(ebuf), fsym) < sizeof (ebuf.e) ||
  51:         N_BADMAG(ebuf.e))
  52:         goto done1;
  53: 
  54:     symbol_offset = N_SYMOFF(ebuf);
  55:     symbol_size = ebuf.e.a_syms;
  56:     strings_offset = N_STROFF(ebuf);
  57:     if (fseek(fsym, symbol_offset, L_SET))
  58:         goto done1;
  59: 
  60:     if (!(fstr = fopen(name, "r")))
  61:         goto done1;
  62: 
  63:     /*
  64: 	 * clean out any left-over information for all valid entries.
  65: 	 * Type and value defined to be 0 if not found; historical
  66: 	 * versions cleared other and desc as well.  Also figure out
  67: 	 * the largest string length so don't read any more of the
  68: 	 * string table than we have to.
  69: 	 */
  70:     for (p = list, entries = maxlen = 0; ISVALID(p); ++p, ++entries) {
  71:         p->n_type = 0;
  72:         p->n_ovly = 0;
  73:         p->n_value = 0;
  74:         if ((len = strlen(p->_name)) > maxlen)
  75:             maxlen = len;
  76:     }
  77:     if (++maxlen > sizeof(sbuf)) {      /* for the NULL */
  78:         (void)fprintf(stderr, "nlist: sym 2 big\n");
  79:         entries = -1;
  80:         goto done2;
  81:     }
  82: 
  83:     for (s = &nbuf; symbol_size; symbol_size -= sizeof(NLIST)) {
  84:         if (fread((char *)s, sizeof(NLIST), 1, fsym) != 1)
  85:             goto done2;
  86:         if (!s->_strx)
  87:             continue;
  88:         if (fseek(fstr, strings_offset + s->_strx, L_SET))
  89:             goto done2;
  90:         (void)fread(sbuf, sizeof(sbuf[0]), maxlen, fstr);
  91:         for (p = list; ISVALID(p); p++)
  92:             if (!strcmp(p->_name, sbuf)) {
  93:                 p->n_value = s->n_value;
  94:                 p->n_type = s->n_type;
  95:                 p->n_ovly = s->n_ovly;
  96:                 if (!--entries)
  97:                     goto done2;
  98:             }
  99:     }
 100: done2:  (void)fclose(fstr);
 101: done1:  (void)fclose(fsym);
 102:     return(entries);
 103: }

Defined functions

Defined variables

Defined typedef's

Defined macros