BSD 4 release

[unix-history] / usr / src / cmd / 1kfix.c

static  char *sccsid = "@(#)1kfix.c     4.1 (Berkeley) 10/15/80";
#include <stdio.h>
#include <a.out.h>
#include <sys/param.h>
#include <sys/vm.h>
char    *malloc();

#define round(a,b) (((a)+((b)-1))&~(b-1))

main(argc, argv)
       int argc;
       char *argv[];
{
       char *tp, *dp, *sp;
       struct exec x, y;
       int io;
       char zeroes[NBPG];

       --argc;
       ++argv;
       if (argc == 0) {
               fprintf(stderr, "usage: 1kfix file ...\n");
               exit(1);
       }
       do {
               io = open(argv[0], 2);
               if (io < 0) {
                       perror(argv[0]);
                       argc--, argv++;
                       continue;
               }
               if (read(io, &x, sizeof x) != sizeof x)
                       goto format;

               switch (x.a_magic) {

               case OMAGIC:
               case NMAGIC:
                       if ((round(x.a_text,NBPG) & CLOFSET) == 0) {
                               fprintf(stderr, "%s: wins as is\n", argv[0]);
                               goto skip;
                       }
                       break;

               case ZMAGIC:
                       lseek(io, NBPG, 0);
                       break;

               default:
format:
                       printf("%s: not object file\n", argv[0]);
                       goto skip;
               }

               tp = malloc(x.a_text);
               dp = malloc(x.a_data);
               sp = malloc(x.a_syms);
               if (read(io, tp, x.a_text) != x.a_text ||
                   read(io, dp, x.a_data) != x.a_data ||
                   read(io, sp, x.a_syms) != x.a_syms) {
                       fprintf(stderr, "%s: short read\n", argv[0]);
                       goto skip;
               }
               close(io);
               io = creat(argv[0], 0755);
               if (io < 0) {
                       perror(argv[0]);
                       goto skip;
               }

               y = x;
               switch (x.a_magic) {

               case ZMAGIC: {
                       int i;
                       for (i = 0; i < 512; i++)
                               if (tp[i] != 0)
                                       break;
                       if (i == 512)
                               printf("%s: already fixed\n", argv[0]);
                       if (x.a_text & CLOFSET) {
                               y.a_text -= NBPG;
                               y.a_data += NBPG;
                       }
                       }
                       break;

               case OMAGIC:
               case NMAGIC:
                       y.a_text = round(x.a_text, NBPG) - NBPG;
                       y.a_data += NBPG;
                       if (y.a_text == 0) {
                               fprintf(stderr, "%s: text size would be 0\n", argv[0]);
                               goto skip;
                       }
               }
               y.a_trsize = y.a_drsize = 0;
               write(io, (char *)&y, sizeof y);
               if (x.a_magic == ZMAGIC)
                       lseek(io, BSIZE, 0);
               write(io, tp, x.a_text);
               if (x.a_magic != ZMAGIC)
                       write(io, zeroes, round(x.a_text, NBPG) - x.a_text);
               write(io, dp, x.a_data);
               write(io, sp, x.a_syms);
               free(tp);
               free(dp);
               free(sp);
skip:
               argc--, argv++;
               close(io);
       } while (argc > 0);
       exit(0);
}