minix/lib/other/nlist.c
2009-11-09 10:26:00 +00:00

71 lines
1.8 KiB
C

/*
* "nlist.c", Peter Valkenburg, january 1989.
*/
#include <lib.h>
#include <string.h>
#include <a.out.h>
#include <sys/types.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>
#define fail(fp) (fclose(fp), -1) /* ret. exp. when nlist fails */
_PROTOTYPE( int nlist, (char *file, struct nlist nl[]));
/*
* Nlist fills fields n_sclass and n_value of array nl with values found in
* non-stripped executable file. Entries that are not found have their
* n_value/n_sclass fields set to 0. Nl ends with a 0 or nul string n_name.
* The return value is -1 on failure, else the number of entries not found.
*/
int nlist(file, nl)
char *file;
struct nlist nl[];
{
int nents, nsrch, nfound, i;
struct nlist nlent;
FILE *fp;
struct exec hd;
/* open executable with namelist */
if ((fp = fopen(file, "r")) == NULL)
return -1;
/* get header and seek to start of namelist */
if (fread((char *) &hd, sizeof(struct exec), 1, fp) != 1 ||
BADMAG(hd) || fseek(fp, A_SYMPOS(hd), SEEK_SET) != 0)
return fail(fp);
/* determine number of entries searched for & reset fields */
nsrch = 0;
while (nl[nsrch].n_name != NULL && *(nl[nsrch].n_name) != '\0') {
nl[nsrch].n_sclass = 0;
nl[nsrch].n_value = 0;
nl[nsrch].n_type = 0; /* for compatability */
nsrch++;
}
/* loop through namelist & fill in user array */
nfound = 0;
for (nents = (hd.a_syms & 0xFFFF) / sizeof(struct nlist);
nents > 0; nents--) {
if (nsrch == nfound)
break; /* no need to look further */
if (fread((char *) &nlent, sizeof(struct nlist), 1, fp) != 1)
return fail(fp);
for (i = 0; i < nsrch; i++)
if (nl[i].n_sclass == 0 &&
strncmp(nl[i].n_name, nlent.n_name,
sizeof(nlent.n_name)) == 0) {
nl[i] = nlent;
nfound++;
break;
}
}
(void) fclose(fp);
return nsrch - nfound;
}