dan@rna.UUCP (Dan Ts'o) (11/27/84)
abc
There are a number of bugs in the recently posted "lu"
(list users) program. Our UNIX is a 4.2BSD VAX.
- When using the "lav" program via a popen("lav"), "lu" managed
reverse the printing of the 5 and 15 minute loadaverages. This
seemed to be because (char *) variables were used to read in
the results from popen(). They have been changed to (double).
- When not using the "lav", but the internal routine to directly
read _avenrun from /dev/kmem (which is all that "lav" does),
"lu" would bomb after several iterations because the /dev/kmem
file descriptor is never closed.
- "lu" runs continuous, thus contributing at least 1 to the load
average itself. The popen("lav") is also inefficient. I inserted
a sleep() call which defaults to 10 seconds, an emperically compromise.
- Instead of opening and closing /dev/kmem all the time, I kept
the file descriptor to /dev/kmem and nlist the kernel once.
- The #else line involving the parameter LOADAV was not acceptable
to our C compiler.
- Its a screen version of
while :
do
w
done
which doesn't even tell you what each user is doing.
Oh well... I had a few minutes and needed a light hack snack...
*** lu.c.org Mon Nov 26 20:54:53 1984
--- lu.c Mon Nov 26 23:31:02 1984
***************
*** 15,20
* lu understands the following options: *
* -f filename use 'filename' as an alternative to /etc/utmp. *
* -s don't use standout mode of terminal. *
* *
************************************************************************
* *
--- 15,21 -----
* lu understands the following options: *
* -f filename use 'filename' as an alternative to /etc/utmp. *
* -s don't use standout mode of terminal. *
+ * -n seconds seconds to sleep between cycles
* *
************************************************************************
* *
***************
*** 61,66
done (), redraw ();
long now,
time ();
for (x = 1; x < argc; x++) {
if (argv[x][0] != '-')
--- 62,68 -----
done (), redraw ();
long now,
time ();
+ int secs = 10;
for (x = 1; x < argc; x++) {
if (argv[x][0] != '-')
***************
*** 72,77
case 's': /* standout mode flag */
sflg = 0;
break;
default:
printf ("usage: %s [-f] [-s]\n", *argv);
exit (0);
--- 74,82 -----
case 's': /* standout mode flag */
sflg = 0;
break;
+ case 'n':
+ secs = atoi(argv[++x]);
+ break;
default:
fprintf (stderr, "usage: %s [-f utmp_file] [-s] [-n seconds]\n", *argv);
exit (0);
***************
*** 73,79
sflg = 0;
break;
default:
! printf ("usage: %s [-f] [-s]\n", *argv);
exit (0);
}
}
--- 78,84 -----
secs = atoi(argv[++x]);
break;
default:
! fprintf (stderr, "usage: %s [-f utmp_file] [-s] [-n seconds]\n", *argv);
exit (0);
}
}
***************
*** 158,163
if (sflg)
standend ();
refresh ();
rewind (fp);
}
}
--- 163,170 -----
if (sflg)
standend ();
refresh ();
+ if (secs > 0)
+ sleep(secs);
rewind (fp);
}
}
***************
*** 268,276
double vec[3];
FILE * pp;
FILE * popen ();
! char *a,
! *b,
! *c;
#ifdef pdp11
loadav (vec);
--- 275,281 -----
double vec[3];
FILE * pp;
FILE * popen ();
! static int kmem = 0;
#ifdef pdp11
loadav (vec);
***************
*** 275,281
#ifdef pdp11
loadav (vec);
sprintf (str, "Load Average: %.02f %.02f %.02f", vec[0], vec[1], vec[2]);
! #else !pdp11 && LOADAV
pp = popen (LOADAV, "r");
fscanf (pp, "%f%f%f", &a, &b, &c);
sprintf (str, "Load Average: %.02f %.02f %.02f", a, b, c);
--- 280,287 -----
#ifdef pdp11
loadav (vec);
sprintf (str, "Load Average: %.02f %.02f %.02f", vec[0], vec[1], vec[2]);
! #else
! #ifdef LOADAV
pp = popen (LOADAV, "r");
fscanf (pp, "%lf%lf%lf", &vec[0], &vec[1], &vec[2]);
sprintf (str, "Load Average: %.02f %.02f %.02f", vec[0], vec[1], vec[2]);
***************
*** 277,284
sprintf (str, "Load Average: %.02f %.02f %.02f", vec[0], vec[1], vec[2]);
#else !pdp11 && LOADAV
pp = popen (LOADAV, "r");
! fscanf (pp, "%f%f%f", &a, &b, &c);
! sprintf (str, "Load Average: %.02f %.02f %.02f", a, b, c);
pclose (pp);
#else
# include <nlist.h>
--- 283,290 -----
#else
#ifdef LOADAV
pp = popen (LOADAV, "r");
! fscanf (pp, "%lf%lf%lf", &vec[0], &vec[1], &vec[2]);
! sprintf (str, "Load Average: %.02f %.02f %.02f", vec[0], vec[1], vec[2]);
pclose (pp);
#else
# include <nlist.h>
***************
*** 287,293
{ "_avenrun" },
{ "" }
};
- register int kmem;
long lseek();
if((kmem = open("/dev/kmem",0)) < 0) {
--- 293,298 -----
{ "_avenrun" },
{ "" }
};
long lseek();
if(kmem == 0) {
***************
*** 290,299
register int kmem;
long lseek();
! if((kmem = open("/dev/kmem",0)) < 0) {
! finish();
! puts("Cant't access /dev/kmem.");
! done();
}
nlist("/vmunix", nlar);
if(!nlar[0].n_type) {
--- 295,307 -----
};
long lseek();
! if(kmem == 0) {
! if ((kmem = open("/dev/kmem",0)) < 0) {
! finish();
! puts("Can't access /dev/kmem.");
! done();
! }
! nlist("/vmunix", nlar);
}
if(!nlar[0].n_type) {
finish();
***************
*** 295,301
puts("Cant't access /dev/kmem.");
done();
}
- nlist("/vmunix", nlar);
if(!nlar[0].n_type) {
finish();
puts("Can't find namelist in vmunix.");
--- 303,308 -----
}
nlist("/vmunix", nlar);
}
if(!nlar[0].n_type) {
finish();
puts("Can't find namelist in vmunix.");
***************
*** 304,309
lseek(kmem,(long)nlar[0].n_value,0);
read(kmem,vec,sizeof(vec));
sprintf(str,"Load Average: %.02f %.02f %.02f", vec[0],vec[1],vec[2]);
#endif pdp11
return (str);
}
--- 311,317 -----
lseek(kmem,(long)nlar[0].n_value,0);
read(kmem,vec,sizeof(vec));
sprintf(str,"Load Average: %.02f %.02f %.02f", vec[0],vec[1],vec[2]);
+ #endif LOADAV
#endif pdp11
return (str);
}mikec@reed.UUCP (Michael Cooper) (11/30/84)
[ All lines don't have rights. ]
The fixes that were mentioned in the <321@rna.UUCP> were fixed and lu was
reposted. Did it not make it out? Would somebody who saw the reposting
let me know????? If nobody saw it I will repost.
Michael Cooper
______________________________________________________________________________
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+---!reed!mikec
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