uptime (coreutils)

[Alfred M. Szmidt]

The following fixes uptime in coreutils to *drum roll* show the
uptime! *applause*.  Have fun with it.  And now to more important
things...


Were do we dump functions that we would like external programs (things
that are not in the Hurd project) to use?  Like fetch_boot_time() for
example.  If for example this hack would get in coreutils, then we
would have this ugly code duplication all over the place.

I might note that fetch_boot_time() is a bad example, since it should
be in coreutils, and `w' should die as to let `who' live, ditto for
our hacked `uptime' script that uses `w'.


--- Makefile.am.~1.33.~   2004-03-12 22:35:37.000000000 -0800
+++ Makefile.am      2004-03-14 05:41:22.000000000 -0800
@@ -61,7 +61,7 @@ nanosec_libs = \
 sleep_LDADD = $(nanosec_libs)
 tail_LDADD = $(nanosec_libs)
 
-uptime_LDADD = $(LDADD) $(GETLOADAVG_LIBS)
+uptime_LDADD = $(LDADD) $(GETLOADAVG_LIBS) -lps
 
 su_LDADD = $(LDADD) $(LIB_CRYPT)
 
--- uptime.c.~1.40.~   2004-03-07 08:04:03.000000000 -0800
+++ uptime.c 2004-03-14 05:22:42.000000000 -0800
@@ -47,6 +47,47 @@ static struct option const longopts[] =
   {NULL, 0, NULL, 0}
 };
 
+#include <hurd.h>
+#include <ps.h>
+
+/* Find the absolute timestamp of when the system was booted.  We
+   define "system boot time" as the task creation time of PID 1
+   (init).  */
+static error_t
+fetch_boot_time (struct timeval *when)
+{
+  struct ps_context *context;
+  struct proc_stat *ps;
+  error_t err;
+
+  err = ps_context_create (getproc (), &context);
+  if (err)
+    error (2, err, "ps_context_create");
+
+  err = ps_context_find_proc_stat (context, 1, &ps);
+  if (err)
+    error (3, err, "ps_context_find_proc_stat");
+
+  err = proc_stat_set_flags (ps, PSTAT_TASK_BASIC);
+  if (!err && !(ps->flags & PSTAT_TASK_BASIC))
+    err = EGRATUITOUS;
+  if (err)
+    {
+      error (0, err, "cannot find boot time");
+      return err;
+    }
+  else
+    {
+      time_value_t *const tv = &proc_stat_task_basic_info (ps)->creation_time;
+      when->tv_sec = tv->seconds;
+      when->tv_usec = tv->microseconds;
+    }
+
+  ps_context_free (context);
+
+  return 0;
+}
+
 static void
 print_uptime (int n, const STRUCT_UTMP *this)
 {
@@ -96,6 +137,14 @@ print_uptime (int n, const STRUCT_UTMP *
   }
 #endif
 
+  {
+    struct timeval result;
+    if (fetch_boot_time (&result))
+      boot_time = 0;
+    else
+      boot_time = result.tv_sec;
+  }
+
   /* Loop through all the utmp entries we just read and count up the valid
      ones, also in the process possibly gleaning boottime. */
   while (n--)