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