From: Martin v. Löwis <martin@v.loewis.de>
Date: Sun, 28 Jul 2002 10:34:08 +0000 (+0000)
Subject: Patch #552812: Better description in "python -h" for -u.
X-Git-Tag: v2.3c1~4853
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=611a7101ca2161903f403e3b70e6087957730b1c;p=python

Patch #552812: Better description in "python -h" for -u.
---

diff --git a/Misc/python.man b/Misc/python.man
index 5cd8816788..2aa1de88f1 100644
--- a/Misc/python.man
+++ b/Misc/python.man
@@ -138,7 +138,11 @@ indentation in a way that makes it depend on the worth of a tab
 expressed in spaces.  Issue an error when the option is given twice.
 .TP
 .B \-u
-Force stdin, stdout and stderr to be totally unbuffered.
+Force stdin, stdout and stderr to be totally unbuffered.  Note that
+there is internal buffering in xreadlines(), readlines() and file-object
+iterators ("for line in sys.stdin") which is not influenced by this
+option.  To work around this, you will want to use "sys.stdin.readline()"
+inside a "while 1:" loop.
 .TP
 .B \-v
 Print a message each time a module is initialized, showing the place
diff --git a/Modules/main.c b/Modules/main.c
index 9ce8bef79f..71b5464e4a 100644
--- a/Modules/main.c
+++ b/Modules/main.c
@@ -62,6 +62,7 @@ static char *usage_2 = "\
 -S     : don't imply 'import site' on initialization\n\
 -t     : issue warnings about inconsistent tab usage (-tt: issue errors)\n\
 -u     : unbuffered binary stdout and stderr (also PYTHONUNBUFFERED=x)\n\
+         see man page for details on internal buffering relating to "-u"\n\
 ";
 static char *usage_3 = "\
 -v     : verbose (trace import statements) (also PYTHONVERBOSE=x)\n\