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freebsd/lib/libutil/setproctitle.c
Peter Wemm 7350dd84a0 If the two recently added sysctl variables exist, use those rather than
the statically compiled PS_STRINGS and USRSTACK variables.  This prevents
programs using setproctitle from coredumping if the kernel VM is increased,
and stops libkvm users (w, ps, etc) from needing to be recompiled if only
the VM layout changes.
1996-02-24 14:37:30 +00:00

127 lines
3.2 KiB
C

/*
* Copyright (c) 1995 Peter Wemm <peter@freebsd.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, is permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice immediately at the beginning of the file, without modification,
* this list of conditions, and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Absolutely no warranty of function or purpose is made by the author
* Peter Wemm.
*
* $Id: setproctitle.c,v 1.1 1995/12/26 22:50:08 peter Exp $
*/
#include <sys/types.h>
#include <sys/param.h>
#include <sys/exec.h>
#include <sys/sysctl.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/pmap.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
/*
* Older FreeBSD 2.0, 2.1 and 2.2 had different ps_strings structures and
* in different locations.
* 1: old_ps_strings at the very top of the stack.
* 2: old_ps_strings at SPARE_USRSPACE below the top of the stack.
* 3: ps_strings at the very top of the stack.
* This attempts to support a kernel built in the #2 and #3 era.
*/
struct old_ps_strings {
char *old_ps_argvstr;
int old_ps_nargvstr;
char *old_ps_envstr;
int old_ps_nenvstr;
};
#define OLD_PS_STRINGS ((struct old_ps_strings *) \
(USRSTACK - SPARE_USRSPACE - sizeof(struct old_ps_strings)))
#if defined(__STDC__) /* from other parts of sendmail */
#include <stdarg.h>
#else
#include <varargs.h>
#endif
#define SPT_BUFSIZE 2048 /* from other parts of sendmail */
extern char * __progname; /* is this defined in a .h anywhere? */
void
#if defined(__STDC__)
setproctitle(const char *fmt, ...)
#else
setproctitle(fmt, va_alist)
const char *fmt;
va_dcl
#endif
{
char *p;
static char buf[SPT_BUFSIZE];
static char *ps_argv[2];
va_list ap;
int mib[2];
struct ps_strings *ps_strings;
size_t len;
#if defined(__STDC__)
va_start(ap, fmt);
#else
va_start(ap);
#endif
buf[sizeof(buf) - 1] = '\0';
if (fmt) {
/* print program name heading for grep */
(void) snprintf(buf, sizeof(buf) - 1, "%s: ", __progname);
/*
* can't use return from sprintf, as that is the count of how
* much it wanted to write, not how much it actually did.
*/
len = strlen(buf);
/* print the argument string */
(void) vsnprintf(buf + len, sizeof(buf) - 1 - len, fmt, ap);
} else {
/* Idea from NetBSD - reset the title on fmt == NULL */
strncpy(buf, __progname, sizeof(buf) - 1);
}
va_end(ap);
ps_strings = NULL;
mib[0] = CTL_KERN;
mib[1] = KERN_PS_STRINGS;
len = sizeof(ps_strings);
if (sysctl(mib, 2, &ps_strings, &len, NULL, 0) < 0 ||
ps_strings == NULL)
ps_strings = PS_STRINGS;
/* PS_STRINGS points to zeroed memory on a style #2 kernel */
if (ps_strings->ps_argvstr) {
/* style #3 */
ps_argv[0] = buf;
ps_argv[1] = NULL;
ps_strings->ps_nargvstr = 1;
ps_strings->ps_argvstr = ps_argv;
} else {
/* style #2 */
OLD_PS_STRINGS->old_ps_nargvstr = 1;
OLD_PS_STRINGS->old_ps_argvstr = buf;
}
}