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authorRoland McGrath <roland@gnu.org>1996-07-14 06:04:09 +0000
committerRoland McGrath <roland@gnu.org>1996-07-14 06:04:09 +0000
commit2064087b5f1a0a3a189fcd6a3012376f5545be31 (patch)
tree6f02a4e4364004352f2d785146b5dc12444e83b9 /manual/startup.texi
parent842907c6f8e6022f443175072e65bc516eb0973b (diff)
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Sun Jul 14 01:51:39 1996 Roland McGrath <roland@delasyd.gnu.ai.mit.edu>cvs/libc-960714
* manual/Makefile (glibc-targets): Variable and targets removed. Sat Jul 13 23:50:17 1996 Roland McGrath <roland@delasyd.gnu.ai.mit.edu> * manual/Makefile (lib): New phony target. Depend on stamp files. ($(objpfx)stamp%-$(subdir)): New rule to create them when necessary. 1996-07-13 Paul Eggert <eggert@twinsun.com> * time/strftime.c (strftime): Use space padding for %e, %k, %l, to match Emacs format-time-string specification. (DO_NUMBER_SPACEPAD): Renamed from DO_NUMBER_NOPAD. Sat Jul 13 20:17:38 1996 Roland McGrath <roland@delasyd.gnu.ai.mit.edu> * elf/dl-deps.c (_dl_map_object_deps): Take new args PRELOADS and NPRELOADS, vector of `struct link_map *'s; add them to the searchlist between MAP and its deps. * elf/link.h: Fix decl. * elf/rtld.c (dl_main): If not secure, parse LD_PRELOAD for colon-separated list of names, map those and pass vector of ptrs as PRELOADS list to _dl_map_object_deps. * elf/dl-runtime.c (_dl_object_relocation_scope): Pass new args to _dl_map_object_deps with empty preload list. * elf/dl-open.c (_dl_open): Likewise. * sysdeps/mach/hurd/dl-sysdep.c (_dl_sysdep_open_zero_fill): Function removed. (__mmap): Pass MACH_PORT_NULL for memobj port when (flags & MAP_ANON). * sysdeps/generic/dl-sysdep.c (_dl_sysdep_open_zero_fill): Conditionalize defn on [! MAP_ANON]. * elf/dl-minimal.c (malloc): Conditionalize use of _dl_zerofd on [! MAP_ANON]. * elf/rtld.c (dl_main): Likewise. * elf/dl-load.c (_dl_zerofd): Conditionalize defn on [! MAP_ANON]. (_dl_map_object_from_fd): Conditionalize initialization of _dl_zerofd. * elf/dl-fini.c (_dl_fini): Skip finalizer for executable itself. Sat Jul 13 02:47:53 1996 David Mosberger-Tang <davidm@azstarnet.com> * stdlib/random.c (__random): Declare as int32_t to be in sync with declaration. * socket/Makefile (headers): Add socketbits.h. * misc/mntent.c (endmntent): Allow for NULL stream. SunOS does it that way. * grp/initgroups.c (initgroups): Add groups that user is a member of, not the ones he is _not_ a member of. * nss/nsswitch.c (known_compare): Make known_compare() a static instead of a local function. The latter are difficult to debug and slow to execute on certain platforms. * sysdeps/posix/ttyname_r.c (ttyname_r): Use sizeof (dev) - 1 in place of sizeof (dev). The size of a literal string includes the NUL byte. * sysdeps/unix/getlogin.c (getlogin): Initialize ut_fd with -1. Thu Jul 11 16:59:10 1996 David Mosberger-Tang <davidm@azstarnet.com> * misc/mntent.c (addmntent): Seek to end of file before writing entry. Return 1 on error, not -1. Tue Jul 9 19:08:05 1996 David Mosberger-Tang <davidm@azstarnet.com> * sysdeps/unix/sysv/linux/syscalls.list: Mark bdflush as EXTRA syscall. Fri Jul 5 18:44:55 1996 David Mosberger-Tang <davidm@azstarnet.com> * sysdeps/unix/sysv/linux/alpha/ioperm.c (port_to_cpu_addr): Size shift amount for Jensen must be 5 not 4. Sat Jul 13 20:04:28 1996 Roland McGrath <roland@delasyd.gnu.ai.mit.edu> * socket/sys/socket.h (struct osockaddr): New type. Sat Jul 13 03:50:53 1996 Ulrich Drepper <drepper@cygnus.com> * misc/Makefile (routines): Add qefgcvt and qefgcvt_r. * misc/efgcvt.c, misc/efgcvt_r.c: Change code so that the `double' and `long double' versions can be generated. * misc/qefgcvt.c, misc/qefgcvt_r.c: New files. Define macros so that included efgcvt{,_r}.c file generate `long double' versions. * stdlib/stdlib.h: Add prototypes for q[efg]cvt() and q[ef]cvt_r() functions. * manual/startup.texi: Document new getsubopt function. * manual/examples/subopt.c: New example program for documenting getsubopt function. Fri Jul 12 23:58:37 1996 Ulrich Drepper <drepper@cygnus.com> * stdlib/Makefile (routines): Add getsubopt. * stdlib/stdlib.h: Add prototype for getsubopt. * stdlib/getsubopt.c: New file. Implement getsubopt function to handle suboption parsing.
Diffstat (limited to 'manual/startup.texi')
-rw-r--r--manual/startup.texi68
1 files changed, 61 insertions, 7 deletions
diff --git a/manual/startup.texi b/manual/startup.texi
index 654a4e8..1313d4c 100644
--- a/manual/startup.texi
+++ b/manual/startup.texi
@@ -83,12 +83,14 @@ allow this three-argument form, so to be portable it is best to write
@code{main} to take two arguments, and use the value of @code{environ}.
@menu
-* Argument Syntax:: By convention, options start with a hyphen.
-* Parsing Options:: The @code{getopt} function.
-* Example of Getopt:: An example of parsing options with @code{getopt}.
-* Long Options:: GNU suggests utilities accept long-named options.
+* Argument Syntax:: By convention, options start with a hyphen.
+* Parsing Options:: The @code{getopt} function.
+* Example of Getopt:: An example of parsing options with @code{getopt}.
+* Long Options:: GNU suggests utilities accept long-named options.
Here is how to do that.
-* Long Option Example:: An example of using @code{getopt_long}.
+* Long Option Example:: An example of using @code{getopt_long}.
+* Suboptions:: Some programs need more detailed options.
+* Suboptions Example:: This shows how it could be done for @code{mount}.
@end menu
@node Argument Syntax
@@ -409,6 +411,58 @@ When @code{getopt_long} has no more options to handle, it returns
@include longopt.c.texi
@end smallexample
+@node Suboptions
+@subsection Parsing of Suboptions
+
+Having a single level of options is sometimes not enough. There might
+be too many options which have to be available or a set of options is
+closely related.
+
+For this case some programs use suboptions. One of the most prominent
+programs is certainly @code{mount}(8). The @code{-o} option take one
+argument which itself is a comma separated list of options. To ease the
+programming of code like this the function @code{getsubopt} is
+available.
+
+@comment stdlib.h
+@deftypefun int getsubopt (char **@var{optionp}, const char* const *@var{tokens}, char **@var{valuep})
+
+The @var{optionp} parameter must be a pointer to a variable containing
+the address of the string to process. When the function returns the
+reference is updated to point to the next suboption or to the
+terminating @samp{\0} character if there is no more suboption available.
+
+The @var{tokens} parameter references an array of strings containing the
+known suboptions. All strings must be @samp{\0} terminated and to mark
+the end a null pointer must be stored. When @code{getsubopt} finds a
+possible legal suboption it compares it with all strings available in
+the @var{tokens} array and returns the index in the string as the
+indicator.
+
+In case the suboption has an associated value introduced by a @samp{=}
+character, a pointer to the value is returned in @var{valuep}. The
+string is @samp{\0} terminated. If no argument is available
+@var{valuep} is set to the null pointer. By doing this the caller can
+check whether a necessary value is given or whether no unexpected value
+is present.
+
+In case the next suboption in the string is not mentioned in the
+@var{tokens} array the starting address of the suboption including a
+possible value is returned in @var{valuep} and the return value of the
+function is @samp{-1}.
+@end deftypefun
+
+@node Suboptions Example
+@subsection Parsing of Suboptions Example
+
+The code which might appear in the @code{mount}(8) program is a perfect
+example of the use of @code{getsubopt}:
+
+@smallexample
+@include subopt.c.texi
+@end smallexample
+
+
@node Environment Variables
@section Environment Variables
@@ -448,9 +502,9 @@ character, since this is assumed to terminate the string.
@menu
-* Environment Access:: How to get and set the values of
+* Environment Access:: How to get and set the values of
environment variables.
-* Standard Environment:: These environment variables have
+* Standard Environment:: These environment variables have
standard interpretations.
@end menu