glibc/sysdeps/unix/nlist.c
1995-02-18 01:27:10 +00:00

92 lines
2.4 KiB
C

/* Copyright (C) 1991 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with the GNU C Library; see the file COPYING. If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
#include <ansidecl.h>
#include <errno.h>
#include <a.out.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
/* Search the executable FILE for symbols matching those in NL,
which is terminated by an element with a NULL `n_un.n_name' member,
and fill in the elements of NL. */
int
DEFUN(nlist, (file, nl),
CONST char *file AND struct nlist *nl)
{
FILE *f;
struct exec header;
size_t nsymbols;
struct nlist *symbols;
unsigned long int string_table_size;
char *string_table;
register size_t i;
if (nl == NULL)
{
errno = EINVAL;
return -1;
}
f = fopen(file, "r");
if (f == NULL)
return -1;
if (fread((PTR) &header, sizeof(header), 1, f) != 1)
goto lose;
if (fseek(f, N_SYMOFF(header), SEEK_SET) != 0)
goto lose;
symbols = (struct nlist *) __alloca(header.a_syms);
nsymbols = header.a_syms / sizeof(symbols[0]);
if (fread((PTR) symbols, sizeof(symbols[0]), nsymbols, f) != nsymbols)
goto lose;
if (fread((PTR) &string_table_size, sizeof(string_table_size), 1, f) != 1)
goto lose;
string_table_size -= sizeof(string_table_size);
string_table = (char *) __alloca(string_table_size);
if (fread((PTR) string_table, string_table_size, 1, f) != 1)
goto lose;
for (i = 0; i < nsymbols; ++i)
{
register struct nlist *nlp;
for (nlp = nl; nlp->n_un.n_name != NULL; ++nlp)
if (!strcmp(nlp->n_un.n_name,
&string_table[symbols[i].n_un.n_strx -
sizeof(string_table_size)]))
{
char *CONST name = nlp->n_un.n_name;
*nlp = symbols[i];
nlp->n_un.n_name = name;
}
}
(void) fclose(f);
return 0;
lose:;
(void) fclose(f);
return -1;
}