Fix #513: option --nostdin: do not attempt to read stdin

No need to add the option to auto-completion scripts
as it does not apply to manual input from a tty.

README.md

@@ -244,6 +244,7 @@ POWER TOYS:
       --cached index|URL   browse a cached page from Wayback Machine
       --suggest            show similar tags when adding bookmarks
       --tacit              reduce verbosity, skip some confirmations
+      --nostdin            do not wait for input (must be first arg)
       --threads N          max network connections in full refresh
                            default N=4, min N=1, max N=10
       -V                   check latest upstream version available

buku

@@ -4914,7 +4914,7 @@ def piped_input(argv, pipeargs=None):
     """
     if not sys.stdin.isatty():
         pipeargs += argv
-        print('waiting for input')
+        print('buku: waiting for input (unexpected? try --nostdin)')
         for s in sys.stdin:
             pipeargs += s.split()
 
@@ -5043,14 +5043,15 @@ def main():
     pipeargs = []
     colorstr_env = os.getenv('BUKU_COLORS')
 
-    try:
-        piped_input(sys.argv, pipeargs)
-    except KeyboardInterrupt:
-        pass
+    if len(sys.argv) >= 2 and sys.argv[1] != '--nostdin':
+        try:
+            piped_input(sys.argv, pipeargs)
+        except KeyboardInterrupt:
+            pass
 
-    # If piped input, set argument vector
-    if pipeargs:
-        sys.argv = pipeargs
+        # If piped input, set argument vector
+        if pipeargs:
+            sys.argv = pipeargs
 
     # Setup custom argument parser
     argparser = ExtendedArgumentParser(
@@ -5203,6 +5204,7 @@ POSITIONAL ARGUMENTS:
     --cached index|URL   browse a cached page from Wayback Machine
     --suggest            show similar tags when adding bookmarks
     --tacit              reduce verbosity, skip some confirmations
+    --nostdin            do not wait for input (must be first arg)
     --threads N          max network connections in full refresh
                          default N=4, min N=1, max N=10
     -V                   check latest upstream version available
@@ -5226,6 +5228,7 @@ POSITIONAL ARGUMENTS:
     addarg('--cached', nargs=1, help=hide)
     addarg('--suggest', action='store_true', help=hide)
     addarg('--tacit', action='store_true', help=hide)
+    addarg('--nostdin', action='store_true', help=hide)
     addarg('--threads', type=int, default=4, choices=range(1, 11), help=hide)
     addarg('-V', dest='upstream', action='store_true', help=hide)
     addarg('-g', '--debug', action='store_true', help=hide)
@@ -5291,7 +5294,7 @@ POSITIONAL ARGUMENTS:
     browse.override_text_browser = False
 
     # Fallback to prompt if no arguments
-    if len(sys.argv) == 1:
+    if len(sys.argv) <= 2 and (len(sys.argv) == 1 or (len(sys.argv) == 2 and args.nostdin)):
         bdb = BukuDb()
         prompt(bdb, None)
         bdb.close_quit(0)

buku.1

@@ -295,6 +295,9 @@ Show a list of similar tags to choose from when adding a new bookmark.
 .BI \--tacit
 Show lesser output. Reduces the verbosity of certain operations like add, update etc.
 .TP
+.BI \--nostdin
+Do not attempt to read data from standard input e.g. when the program is not executed from a tty.
+.TP
 .BI \--threads
 Maximum number of parallel network connection threads to use during full DB refresh. By default 4 connections are spawned.
 .I N