Add help on usage.

Notice that you must supply a - argument to read  from std:in now.
Otherwise you will get an error.

[[Imported from SVN: r3335]]

bin/hierarchicviewer.py

@@ -153,19 +153,54 @@ class PeriodicActionThread (threading.Thread):
 
 
 
+def usage():
+    print 'SYNOPSIS'
+    print '    python hierarchicviewer.py [OPTIONS] FILE'
+    print '    python hierarchicviewer.py [OPTIONS] -'
+    print ''
+    print 'DESCRIPTION'
+    print '    If FILE was given view content of file in a hierarchic view.'
+    print '    If - is given view standard input in a hierarchic view.'
+    print '    Input should contain UP and DOWN indicators that indicate'
+    print '    to switch the level in the output hierarchy correspondingly.'
+    print ''
+    print '    --help'
+    print '        View this help text.'
+    print ''
+    print '    -u REGEX , --up=REGEX'
+    print '        Lines matching REGEX are considered as indicator to switch'
+    print '        up in the hierarchy. (default: \'^ *\\}\')'
+    print ''
+    print '    -d REGEX , --down=REGEX'
+    print '        Lines matching REGEX are considered as indicator to switch'
+    print '        down in the hierarchy. (default: \'^ *\\{\')'
+    print ''
+    print '    -h, --hideupdown'
+    print '        Hide lines that contain UP or DOWN indicators in the output.'
+    print ''
+    print '    -n, --nofollow'
+    print '        If supplied the view does not follow if new lines are appended.'
+    print ''
+    print '    -t TIMEOUT, --timeout=TIMEOUT'
+    print '        The input buffer it cleared periodically and added to the'
+    print '        hierarchic view after TIMEOUT seconds. (default: 0.1)'
+
 
 def main(args):
 
     try:
-        (opts, args) = getopt.getopt(sys.argv[1:], "t:u:d:hn", ["timeout=", "up=", "down=", "hideupdown", "nofollow", "noappend"])
+        (opts, args) = getopt.getopt(sys.argv[1:], "t:u:d:hn", ["timeout=", "up=", "down=", "hideupdown", "nofollow", "noappend", "help"])
     except getopt.GetoptError, err:
         # print help information and exit:
         print str(err) # will print something like "option -a not recognized"
-#        usage()
+        print ''
+        usage()
         sys.exit(2)
 
-    # input file (default: stdin)
-    infile = sys.stdin
+    for (o, a) in opts:
+        if o in ("--help",):
+            usage()
+            return
 
     # timeout to clear buffer and view items (default: 0.1s)
     timeout = 0.1
@@ -185,11 +220,22 @@ def main(args):
     # switch to determine if view follows appended lines (default: True)
     follow = True
 
-    if (len(args)>0):
+    if (len(args)==1):
         if (args[0]=='-'):
             infile = sys.stdin
         else:
-            infile = file(sys.argv[1], 'r')
+            try:
+                infile = file(args[0], 'r')
+            except IOError:
+                print 'Could not open file:', args[0]
+                print ''
+                usage()
+                sys.exit(2)
+    else:
+        print 'You did not supply a file or the - argument.'
+        print ''
+        usage()
+        sys.exit(2)
 
     for (o, a) in opts:
         if o in ("-t", "--timeout"):