Merge branch 'awesomeclaw/procps-master'

References:
 procps-ng/procps!62

Signed-off-by: Craig Small <csmall@dropbear.xyz>

NEWS

@@ -10,6 +10,7 @@ procps-ng NEXT
   * top: ensure config file backward compatibility         Debian #951335
   * top: add command line 'e' for symmetry with 'E'        issue #165
   * vmstat: Wide mode gives wider proc columns             merge #48
+  * watch: Add environment variable for interval           merge #62
 
 procps-ng-3.3.16
 ----------------

watch.1

@@ -1,4 +1,4 @@
-.TH WATCH 1 "2018-03-03" "procps-ng" "User Commands"
+.TH WATCH 1 "2020-05-12" "procps-ng" "User Commands"
 .SH NAME
 watch \- execute a program periodically, showing output fullscreen
 .SH SYNOPSIS
@@ -21,7 +21,8 @@ has changed at least once since first iteration.
 \fB\-n\fR, \fB\-\-interval\fR \fIseconds\fR
 Specify update interval.  The command will not allow quicker than 0.1 second
 interval, in which the smaller values are converted. Both '.' and ',' work
-for any locales.
+for any locales. The WATCH_INTERVAL environment can be used to persistently
+set a non-default interval (following the same rules and formatting).
 .TP
 \fB\-p\fR, \fB\-\-precise\fR
 Make
@@ -100,6 +101,16 @@ failed, or command exited up on error.
 .TP
 .B other
 The watch will propagate command exit status as child exit status.
+.SH ENVIRONMENT
+The behaviour of
+.B watch
+is affected by the following environment variables.
+
+.TP
+.B WATCH_INTERVAL
+Update interval, follows the same rules as the
+.B \-\-interval
+command line option.
 .SH NOTES
 POSIX option processing is used (i.e., option processing stops at
 the first non\-option argument).  This means that flags after

watch.c

@@ -668,6 +668,7 @@ int main(int argc, char *argv[])
 {
 	int optc;
 	double interval = 2;
+	char *interval_string;
 	char *command;
 	char **command_argv;
 	int command_length = 0;	/* not including final \0 */
@@ -701,6 +702,10 @@ int main(int argc, char *argv[])
 	textdomain(PACKAGE);
 	atexit(close_stdout);
 
+	interval_string = getenv("WATCH_INTERVAL");
+	if(interval_string != NULL)
+		interval = strtod_nol_or_err(interval_string, _("Could not parse interval from WATCH_INTERVAL"));
+
 	while ((optc =
 		getopt_long(argc, argv, "+bced::ghn:pvtx", longopts, (int *)0))
 	       != EOF) {
@@ -730,10 +735,6 @@ int main(int argc, char *argv[])
 			break;
 		case 'n':
 			interval = strtod_nol_or_err(optarg, _("failed to parse argument"));
-			if (interval < 0.1)
-				interval = 0.1;
-			if (interval > UINT_MAX)
-				interval = UINT_MAX;
 			break;
 		case 'p':
 			precise_timekeeping = 1;
@@ -750,6 +751,11 @@ int main(int argc, char *argv[])
 		}
 	}
 
+	if (interval < 0.1)
+		interval = 0.1;
+	if (interval > UINT_MAX)
+		interval = UINT_MAX;
+
 	if (optind >= argc)
 		usage(stderr);