cal: support alone month name parameter

For example 'cal August' to print August for the current year.

Signed-off-by: Karel Zak <kzak@redhat.com>

2 files changed, 16 insertions, 7 deletions

diff --git a/misc-utils/cal.1 b/misc-utils/cal.1
index 2048e95e27..39378cfe2a 100644
--- a/misc-utils/cal.1
+++ b/misc-utils/cal.1
@@ -44,7 +44,7 @@ cal \- display a calendar
 .br
 .B cal
 [options]
-.RI <timestamp>
+.RI <timestamp|monthname>
 .SH DESCRIPTION
 .B cal
 displays a simple calendar.  If no arguments are specified, the current
@@ -103,10 +103,13 @@ Specifies the \fIyear\fR to be displayed; note the year must be fully specified:
 .B "cal 89"
 will not display a calendar for 1989.
 .TP
-\fBSingle string parameter (e.g. 'cal tomorrow')\fR
-Specifies \fItimestamp\fR. The special placeholders are accepted when parsing timestamp, "now" may be used to
-refer to the current time, "today", "yesterday", "tomorrow" refer to
-of the current day, the day before or the next day, respectively.
+\fBSingle string parameter (e.g. 'cal tomorrow' or 'cal August')\fR
+Specifies \fItimestamp\fR or a \fImonth name\fR according to the current
+locales.
+.sp
+The special placeholders are accepted when parsing timestamp, "now" may be used
+to refer to the current time, "today", "yesterday", "tomorrow" refer to of the
+current day, the day before or the next day, respectively.
 .sp
 The relative date specifications are also accepted, in this case "+" is
 evaluated to the current time plus the specified time span. Correspondingly, a
diff --git a/misc-utils/cal.c b/misc-utils/cal.c
index aaa2943e66..5c56e74805 100644
--- a/misc-utils/cal.c
+++ b/misc-utils/cal.c
@@ -410,10 +410,14 @@ int main(int argc, char **argv)
 
 	if (argc == 1 && !isdigit_string(*argv)) {
 		usec_t x;
+		/* cal <timestamp> */
 		if (parse_timestamp(*argv, &x) == 0)
 			now = (time_t) (x / 1000000);
+		/* cal <monthname> */
+		else if ((ctl.req.month = monthname_to_number(&ctl, *argv)) > 0)
+			time(&now);	/* this year */
 		else
-			errx(EXIT_FAILURE, _("failed to parse timestamp"));
+			errx(EXIT_FAILURE, _("failed to parse timestamp or unknown month name: %s"), *argv);
 		argc = 0;
 	} else
 		time(&now);
@@ -460,7 +464,8 @@ int main(int argc, char **argv)
 	case 0:
 		ctl.req.day = local_time->tm_yday + 1;
 		ctl.req.year = local_time->tm_year + 1900;
-		ctl.req.month = local_time->tm_mon + 1;
+		if (!ctl.req.month)
+			ctl.req.month = local_time->tm_mon + 1;
 		break;
 	default:
 		usage(stderr);
@@ -969,6 +974,7 @@ static void __attribute__ ((__noreturn__)) usage(FILE * out)
 {
 	fputs(USAGE_HEADER, out);
 	fprintf(out, _(" %s [options] [[[day] month] year]\n"), program_invocation_short_name);
+	fprintf(out, _(" %s [options] <timestamp|monthname>\n"), program_invocation_short_name);
 
 	fputs(USAGE_SEPARATOR, out);
 	fputs(_("Display a calendar, or some part of it.\n"), out);