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Path: utzoo!mnetor!seismo!rutgers!mit-eddie!bu-cs!budd
From: budd@bu-cs.BU.EDU (Philip Budne)
Newsgroups: net.sources
Subject: file command which identifies core files
Message-ID: <3615@bu-cs.BU.EDU>
Date: Tue, 20-Jan-87 16:22:34 EST
Article-I.D.: bu-cs.3615
Posted: Tue Jan 20 16:22:34 1987
Date-Received: Wed, 21-Jan-87 02:03:51 EST
Organization: Boston U. Comp. Sci.
Lines: 54
Keywords: file core diff 4.3

Here is a context diff to 4.3 file.c that tries to identify a core
file, and type out the name of the command which dumped.  The idea
comes from SUNos (!) but SUN core files are different (they start with
a magic number for one thing).

Its less than full graceful, since it re-reads the top of the file,
but hey, it works.

*** file.c.orig	Thu Mar  6 19:34:29 1986
--- file.c	Tue Jan 20 12:14:30 1987
***************
*** 6,11 ****
--- 6,13 ----
   */
  
  #include <sys/param.h>
+ #include <sys/dir.h>		/* budd for user.h */
+ #include <sys/user.h>		/* budd */
  #include <sys/stat.h>
  #include <stdio.h>
  #include <ctype.h>
***************
*** 288,295 ****
  	for(i=0; i < in; i++)if(buf[i]&0200){
  		if (buf[0]=='\100' && buf[1]=='\357')
  			printf("troff (CAT) output\n");
! 		else
! 			printf("data\n"); 
  		return;
  	}
  	if (mbuf.st_mode&((S_IEXEC)|(S_IEXEC>>3)|(S_IEXEC>>6))) {
--- 290,311 ----
  	for(i=0; i < in; i++)if(buf[i]&0200){
  		if (buf[0]=='\100' && buf[1]=='\357')
  			printf("troff (CAT) output\n");
! 		else {			/* budd ... */
! 		    union {
! 			struct user us;
! 			char pad[UPAGES][NBPG];
! 		    } u_;
! # define u u_.us
! 		    lseek( ifile, 0L, 0);
! 		    if( read(ifile, &u_, sizeof u_ ) == sizeof u_ ) {
! 			int p = UPAGES + u.u_dsize + u.u_ssize;
! 			if( p * NBPG == mbuf.st_size ) {
! 			    printf("core from %s\n", u.u_comm );
! 			    return;
! 			}
! 		    }
! 		    printf("data\n"); 
! 		}			/* ... budd */
  		return;
  	}
  	if (mbuf.st_mode&((S_IEXEC)|(S_IEXEC>>3)|(S_IEXEC>>6))) {