add --version and --help

1 files changed, 20 insertions, 1 deletions

diff --git a/src/tail.c b/src/tail.c
index 138c22894..d3bc8cd62 100644
--- a/src/tail.c
+++ b/src/tail.c
@@ -50,6 +50,7 @@
 #include <sys/types.h>
 #include <signal.h>
 #include "system.h"
+#include "version.h"
 
 /* Number of items to tail. */
 #define DEFAULT_NUMBER 10
@@ -111,6 +112,12 @@ char *program_name;
 /* Nonzero if we have ever read standard input. */
 static int have_read_stdin;
 
+/* If non-zero, display usage information and exit.  */
+static int flag_help;
+
+/* If non-zero, print the version on standard error.  */
+static int flag_version;
+
 static struct option const long_options[] =
 {
   {"bytes", required_argument, NULL, 'c'},
@@ -119,6 +126,8 @@ static struct option const long_options[] =
   {"quiet", no_argument, NULL, 'q'},
   {"silent", no_argument, NULL, 'q'},
   {"verbose", no_argument, NULL, 'v'},
+  {"help", no_argument, &flag_help, 1},
+  {"version", no_argument, &flag_version, 1},
   {NULL, 0, NULL, 0}
 };
 
@@ -208,6 +217,9 @@ main (argc, argv)
     {
       switch (c)
 	{
+	case 0:
+	  break;
+
 	case 'c':
 	  unit_size = 1;
 	  parse_unit (optarg);
@@ -244,6 +256,12 @@ main (argc, argv)
 	}
     }
 
+  if (flag_version)
+    fprintf (stderr, "%s\n", version_string);
+
+  if (flag_help)
+    usage ();
+
   if (number == -1)
     number = DEFAULT_NUMBER;
 
@@ -987,7 +1005,8 @@ usage ()
 {
   fprintf (stderr, "\
 Usage: %s [-c [+]N[bkm]] [-n [+]N] [-fqv] [--bytes=[+]N[bkm]] [--lines=[+]N]\n\
-       [--follow] [--quiet] [--silent] [--verbose] [file...]\n\
+       [--follow] [--quiet] [--silent] [--verbose] [--help] [--version]\n\
+       [file...]\n\
        %s [{-,+}Nbcfklmqv] [file...]\n", program_name, program_name);
   exit (1);
 }