This is the mail archive of the
libc-alpha@sourceware.org
mailing list for the glibc project.
[PATCH] manual: Document optind zero set behaviour (BZ#23157)
- From: Adhemerval Zanella <adhemerval dot zanella at linaro dot org>
- To: libc-alpha at sourceware dot org
- Date: Mon, 21 May 2018 16:38:59 -0300
- Subject: [PATCH] manual: Document optind zero set behaviour (BZ#23157)
POSIX [1] does not explicit state the expected way to rescans the same
vector more than once. FreeBSD [2], for instance, exports a non-standard
variable 'optreset' which must be set to '1' prior the second and each
additional call to 'getopt'. GLIBC in turn requires the program to
reset 'optind' to 0 instead (and POSIX states the behavior is unspecified).
Unfortunately this is not documented on the manual, only on man-pages [3]
(on NOTES). This patch adds an explanation of this behavior on manual.
* manual/getopt.texi: Document optind zero set behaviour.
[1] http://pubs.opengroup.org/onlinepubs/9699919799/
[2] https://www.freebsd.org/cgi/man.cgi?getopt(3)
[3] http://man7.org/linux/man-pages/man3/getopt.3.html
---
ChangeLog | 4 ++++
manual/getopt.texi | 6 ++++++
2 files changed, 10 insertions(+)
diff --git a/manual/getopt.texi b/manual/getopt.texi
index 5485fc4..a4f6366 100644
--- a/manual/getopt.texi
+++ b/manual/getopt.texi
@@ -45,6 +45,12 @@ of the @var{argv} array to be processed. Once @code{getopt} has found
all of the option arguments, you can use this variable to determine
where the remaining non-option arguments begin. The initial value of
this variable is @code{1}.
+
+Resetting the variable value to @code{0} forces the invocation of an
+internal initialization routine and it is used mainly when a program
+wants to rescan the same vector more than once. It also should be used
+to scan multiple argument vectors or if @code{POSIXLY_CORRECT} is changed
+between scans.
@end deftypevar
@deftypevar {char *} optarg
--
2.7.4