[PATCH 10/23] getopt.3: Further clarification of optstring

[Alejandro Colomar <alx.manpages@gmail.com>]

From: "James O. D. Hunt" <jamesodhunt@gmail.com>

Explain that `optstring` cannot contain a semi-colon (`;`) character.

Also explain that `optstring` can include `+` as an option character,
possibly in addition to that character being used as the first character
in `optstring` to denote `POSIXLY_CORRECT` behaviour.

Signed-off-by: James O. D. Hunt <jamesodhunt@gmail.com>
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
---
 man3/getopt.3 | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/man3/getopt.3 b/man3/getopt.3
index ce4c28088..315224c64 100644
--- a/man3/getopt.3
+++ b/man3/getopt.3
@@ -130,7 +130,7 @@ A legitimate option character is any visible one byte
 .BR ascii (7)
 character (for which
 .BR isgraph (3)
-would return nonzero) that is not \(aq\-\(aq or \(aq:\(aq.
+would return nonzero) that is not \(aq\-\(aq, \(aq:\(aq  or \(aq;\(aq.
 If such a
 character is followed by a colon, the option requires an argument, so
 .BR getopt ()
@@ -166,6 +166,14 @@ If the first character of
 .B POSIXLY_CORRECT
 is set, then option processing stops as soon as a nonoption argument is
 encountered.
+If \(aq+\(aq is not the first character of
+.IR optstring ,
+it is treated as a normal option.
+If
+.B POSIXLY_CORRECT
+behaviour is required in this case
+.I optstring
+will contain two \(aq+\(aq symbols.
 If the first character of \fIoptstring\fP is \(aq\-\(aq, then
 each nonoption \fIargv\fP-element is handled as if it were the argument of
 an option with character code 1.  (This is used by programs that were
-- 
2.32.0