Add -p|--pretty option to uptime(1) for pretty output.

This patch adds the -p option to the uptime(1) command, which changes
the uptime displayed from something like:

 10:35:52 up  2:33,  1 user,  load average: 1.69, 1.65, 1.63

to:

 up 2 hours, 33 minutes

I originally implemented this as the up(1) program about 14 years ago.
In 2008 or 2009, I created a patch for procps to add this functionality
to uptime and submitted it to the project.  Never heard from the
project and no new releases of procps had been made.  Then I found out
about this project and decided to port my patch to it.  So here it is.

This is really just for fun.  There is no real technical reason to
have this functionality.  But even now, 14 years later, I still get
emails asking where the source code for up is.  So I thought it would
be nice for the uptime command on Linux to sport the up functionality
by default.

7 files changed, 101 insertions, 34 deletions

diff --git a/AUTHORS b/AUTHORS
index 1ad2719..70680cf 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -43,6 +43,7 @@ George Bonser <george@captech.com>
 uptime:
 Larry Greenfield <greenfie@gauss.rutgers.edu>
 Michael K. Johnson <johnsonm@sunsite.unc.edu>
+David Cantrell <david.l.cantrell@gmail.com>
 
 vmstat:
 Henry Ware <al172@yfn.ysu.edu>.
diff --git a/proc/whattime.c b/proc/whattime.c
index d2785a8..5064cec 100644
--- a/proc/whattime.c
+++ b/proc/whattime.c
@@ -27,10 +27,11 @@
 static char buf[128];
 static double av[3];
 
-char *sprint_uptime(void) {
+char *sprint_uptime(int human_readable) {
   struct utmp *utmpstruct;
-  int upminutes, uphours, updays;
+  int upminutes, uphours, updays, upweeks, upyears, updecades;
   int pos;
+  int comma;
   struct tm *realtime;
   time_t realseconds;
   int numuser;
@@ -38,50 +39,107 @@ char *sprint_uptime(void) {
 
 /* first get the current time */
 
-  time(&realseconds);
-  realtime = localtime(&realseconds);
-  pos = sprintf(buf, " %02d:%02d:%02d ",
-    realtime->tm_hour, realtime->tm_min, realtime->tm_sec);
+  if (!human_readable) {
+    time(&realseconds);
+    realtime = localtime(&realseconds);
+    pos = sprintf(buf, " %02d:%02d:%02d ",
+      realtime->tm_hour, realtime->tm_min, realtime->tm_sec);
+  }
 
 /* read and calculate the amount of uptime */
 
   uptime(&uptime_secs, &idle_secs);
 
-  updays = (int) uptime_secs / (60*60*24);
+  if (human_readable) {
+    updecades = (int) uptime_secs / (60*60*24*365*10);
+    upyears = ((int) uptime_secs / (60*60*24*365)) % 10;
+    upweeks = ((int) uptime_secs / (60*60*24*7)) % 52;
+    updays = ((int) uptime_secs / (60*60*24)) % 7;
+  }
+  else
+    updays = (int) uptime_secs / (60*60*24);
+
   strcat (buf, "up ");
   pos += 3;
-  if (updays)
-    pos += sprintf(buf + pos, "%d day%s, ", updays, (updays != 1) ? "s" : "");
+
+  if (!human_readable) {
+    if (updays)
+      pos += sprintf(buf + pos, "%d day%s, ", updays, (updays != 1) ? "s" : "");
+  }
+
   upminutes = (int) uptime_secs / 60;
   uphours = upminutes / 60;
   uphours = uphours % 24;
   upminutes = upminutes % 60;
-  if(uphours)
-    pos += sprintf(buf + pos, "%2d:%02d, ", uphours, upminutes);
-  else
-    pos += sprintf(buf + pos, "%d min, ", upminutes);
+
+  if (!human_readable) {
+    if(uphours)
+      pos += sprintf(buf + pos, "%2d:%02d, ", uphours, upminutes);
+    else
+      pos += sprintf(buf + pos, "%d min, ", upminutes);
 
 /* count the number of users */
 
-  numuser = 0;
-  setutent();
-  while ((utmpstruct = getutent())) {
-    if ((utmpstruct->ut_type == USER_PROCESS) &&
-       (utmpstruct->ut_name[0] != '\0'))
-      numuser++;
+    numuser = 0;
+    setutent();
+    while ((utmpstruct = getutent())) {
+      if ((utmpstruct->ut_type == USER_PROCESS) &&
+         (utmpstruct->ut_name[0] != '\0'))
+        numuser++;
+    }
+    endutent();
+
+    pos += sprintf(buf + pos, "%2d user%s, ", numuser, numuser == 1 ? "" : "s");
+
+    loadavg(&av[0], &av[1], &av[2]);
+
+    pos += sprintf(buf + pos, " load average: %.2f, %.2f, %.2f",
+		   av[0], av[1], av[2]);
   }
-  endutent();
 
-  pos += sprintf(buf + pos, "%2d user%s, ", numuser, numuser == 1 ? "" : "s");
+  if (human_readable) {
+    comma = 0;
+
+    if (updecades) {
+      pos += sprintf(buf + pos, "%d %s", updecades,
+                     updecades > 1 ? "decades" : "decade");
+      comma += 1;
+    }
 
-  loadavg(&av[0], &av[1], &av[2]);
+    if (upyears) {
+      pos += sprintf(buf + pos, "%s%d %s", comma > 0 ? ", " : "", upyears,
+                     upyears > 1 ? "years" : "year");
+      comma += 1;
+    }
 
-  pos += sprintf(buf + pos, " load average: %.2f, %.2f, %.2f",
-		 av[0], av[1], av[2]);
+    if (upweeks) {
+      pos += sprintf(buf + pos, "%s%d %s", comma > 0 ? ", " : "", upweeks,
+                     upweeks > 1 ? "weeks" : "week");
+      comma += 1;
+    }
+
+    if (updays) {
+      pos += sprintf(buf + pos, "%s%d %s", comma > 0 ? ", " : "", updays,
+                     updays > 1 ? "days" : "day");
+      comma += 1;
+    }
+
+    if (uphours) {
+      pos += sprintf(buf + pos, "%s%d %s", comma > 0 ? ", " : "", uphours,
+                     uphours > 1 ? "hours" : "hour");
+      comma += 1;
+    }
+
+    if (upminutes) {
+      pos += sprintf(buf + pos, "%s%d %s", comma > 0 ? ", " : "", upminutes,
+                     upminutes > 1 ? "minutes" : "minute");
+      comma += 1;
+    }
+  }
 
   return buf;
 }
 
-void print_uptime(void) {
-  printf("%s\n", sprint_uptime());
+void print_uptime(int human_readable) {
+  printf("%s\n", sprint_uptime(human_readable));
 }
diff --git a/proc/whattime.h b/proc/whattime.h
index 891ccd3..5ac5850 100644
--- a/proc/whattime.h
+++ b/proc/whattime.h
@@ -5,8 +5,8 @@
 
 EXTERN_C_BEGIN
 
-extern void print_uptime(void);
-extern char *sprint_uptime(void);
+extern void print_uptime(int human_readable);
+extern char *sprint_uptime(int human_readable);
 
 EXTERN_C_END
 
diff --git a/top/top.c b/top/top.c
index 853a64e..73aa282 100644
--- a/top/top.c
+++ b/top/top.c
@@ -3388,10 +3388,10 @@ static void summary_show (void) {
    // Display Uptime and Loadavg
    if (isROOM(View_LOADAV, 1)) {
       if (!Rc.mode_altscr)
-         show_special(0, fmtmk(LOADAV_line, Myname, sprint_uptime()));
+         show_special(0, fmtmk(LOADAV_line, Myname, sprint_uptime(0)));
       else
          show_special(0, fmtmk(CHKw(w, Show_TASKON)? LOADAV_line_alt : LOADAV_line
-            , w->grpname, sprint_uptime()));
+            , w->grpname, sprint_uptime(0)));
       Msg_row += 1;
    }
 
diff --git a/uptime.1 b/uptime.1
index e5fac2e..9b5dd0c 100644
--- a/uptime.1
+++ b/uptime.1
@@ -25,6 +25,9 @@ is loaded all the time while on a 4 CPU system it means it was idle 75% of
 the time.
 .SH OPTIONS
 .TP
+\fB\-p\fR, \fB\-\-pretty\fR
+show uptime in pretty format
+.TP
 \fB\-h\fR, \fB\-\-help\fR
 display this help text
 .TP
diff --git a/uptime.c b/uptime.c
index 8957ce1..557b08c 100644
--- a/uptime.c
+++ b/uptime.c
@@ -13,6 +13,7 @@ static void __attribute__ ((__noreturn__)) usage(FILE * out)
 	fputs(USAGE_HEADER, out);
 	fprintf(out, _(" %s [options]\n"), program_invocation_short_name);
 	fputs(USAGE_OPTIONS, out);
+	fputs(_(" -p, --pretty   show uptime in pretty format\n"), out);
 	fputs(USAGE_HELP, out);
 	fputs(USAGE_VERSION, out);
 	fprintf(out, USAGE_MAN_TAIL("uptime(1)"));
@@ -22,9 +23,10 @@ static void __attribute__ ((__noreturn__)) usage(FILE * out)
 
 int main(int argc, char **argv)
 {
-	int c;
+	int c, p = 0;
 
 	static const struct option longopts[] = {
+		{"pretty", no_argument, NULL, 'p'},
 		{"help", no_argument, NULL, 'h'},
 		{"version", no_argument, NULL, 'V'},
 		{NULL, 0, NULL, 0}
@@ -35,8 +37,11 @@ int main(int argc, char **argv)
 	bindtextdomain(PACKAGE, LOCALEDIR);
 	textdomain(PACKAGE);
 
-	while ((c = getopt_long(argc, argv, "hV", longopts, NULL)) != -1)
+	while ((c = getopt_long(argc, argv, "phV", longopts, NULL)) != -1)
 		switch (c) {
+		case 'p':
+			p = 1;
+			break;
 		case 'h':
 			usage(stdout);
 		case 'V':
@@ -46,6 +51,6 @@ int main(int argc, char **argv)
 			usage(stderr);
 		}
 
-	print_uptime();
+	print_uptime(p);
 	return EXIT_SUCCESS;
 }
diff --git a/w.c b/w.c
index cded162..0dbe333 100644
--- a/w.c
+++ b/w.c
@@ -424,7 +424,7 @@ int main(int argc, char **argv)
 
 	if (header) {
 		/* print uptime and headers */
-		print_uptime();
+		print_uptime(0);
 		/* Translation Hint: Following five uppercase messages are
 		 * headers. Try to keep alignment intact.  */
 		printf(_("%-*s TTY      "), userlen, _("USER"));