BSD 3 release

[unix-history] / usr / src / cmd / symorder.c

/* symorder orderlist symbolfile
*  orderlist is a file containing symbols to be found in symbolfile,
*      1 symbol per line.
*  symbolfile is updated in place to put the requested symbols first
*      in the symbol table, in the order specified.  This is done
*      by swapping the old symbols in the required spots with the
*      new ones.  If all of the order symbols are not found, an
*      error is generated.
*
*  Modelled after nlist.c the nlist subroutine, which has been
*      modified to succeed as soon as all sought symbols are found.
*
*  This program was specifically designed to cut down on the read
*      overhead of systat(ss) when getting symbols from /unix.
*/

#include <stdio.h>
#include <a.out.h>
int a_magic[] = {A_MAGIC1, A_MAGIC2, A_MAGIC3, A_MAGIC4, 0};
#define SPACE 100

main(argc, argv)
char *argv[];
{
       register struct nlist *p, *q;
       register FILE *f;
       register int sa, na, i, j;
       int nsym = 0, symfound = 0, n, o;
       struct nlist nl1, nl2;
       char buf[20];
       struct nlist order[SPACE];
       struct exec exec;

       if(argc != 3) {
               fprintf(stderr, "Usage: symorder orderlist file\n");
               exit(1);
       }
       if((f = fopen(argv[1], "r")) == NULL) {
               fprintf(stderr, "Can't open "); perror(argv[1]);
               exit(1);
       }
       for(p = order; fgets(buf, sizeof buf, f) != NULL; p++, nsym++)
               for(i = 0; i < 8 && buf[i] != '\n'; i++)
                       p->n_name[i] = buf[i];
       fclose(f);
/***    for(i = 0; i < nsym; i++)                       ***/
/***            printf("\"%.8s\"\n", order[i].n_name);  ***/
/***    printf("--------\n");                           ***/
       if((f = fopen(argv[2], "r")) == NULL) {
               fprintf(stderr, "Can't open "); perror(argv[2]);
               exit(1);
       }
       if((o = open(argv[2], 1)) < 0) {
               fprintf(stderr, "Can't update "); perror(argv[2]);
               exit(1);
       }
       if((fread(&exec, sizeof exec, 1, f)) != 1) {
               fprintf(stderr, "Can't read "); perror(argv[2]);
               exit(1);
       }
       for(i=0; a_magic[i]; i++)
               if(a_magic[i] == exec.a_magic) break;
       if(a_magic[i] == 0){
               fprintf(stderr, "Bad Header on %s\n", argv[2]);
               exit(1);
       }
       sa = exec.a_text + exec.a_data;
       sa += exec.a_trsize + exec.a_drsize;
       sa += sizeof exec;
       na = sa;
       fseek(f, sa, 0);
       n = exec.a_syms;

       while(n && symfound < nsym) {
               if(fread(&nl1, sizeof nl1, 1, f) != 1) {
                       fprintf(stderr, "Short file "); perror(argv[2]);
                       exit(1);
               }
/***    printf("\"%.8s\"\n", nl1.n_name);       ***/
               na += sizeof nl1;
               n -= sizeof nl1;
/***    printf("Trying ");                      ***/
               for(j = 0; j < nsym; j++) {
/***    printf("%s ", order[j].n_name);         ***/
                       for(i = 0; i < 8; i++)
                               if(nl1.n_name[i] != order[j].n_name[i])
                                       goto cont;
/***    printf("Found: %.8s\n", nl1.n_name);    ***/
                       if (order[j].n_value)
                               goto cont;
                       order[j].n_value = 1;
                       fseek(f, (i = (sa+(j * sizeof nl1))), 0);
                       if(fread(&nl2, sizeof nl2, 1, f) != 1)
                               printf("Read err on 2nd sym\n");
                       lseek(o, i, 0);
                       if(write(o, &nl1, sizeof nl1) == -1)
                               perror("write1");
                       lseek(o, na-sizeof nl1, 0);
                       if(write(o, &nl2, sizeof nl2) == -1)
                               perror("write2");
                       fseek(f, 0, 0);
                       fseek(f, na, 0);
                       symfound++;
                       break;
       cont:           ;

               }
/***    printf("\n");                           ***/
       }
       if(symfound < nsym) {
               fprintf(stderr, "%d Syms not found:\n", nsym - symfound);
               for (i = 0; i < nsym; i++) {
                       if (order[i].n_value == 0)
                               printf("%.8s\n", order[i].n_name);
               }
       }
}