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diff --git a/manual/getopt.texi b/manual/getopt.texi deleted file mode 100644 index a71c3731aa..0000000000 --- a/manual/getopt.texi +++ /dev/null @@ -1,330 +0,0 @@ -@node Getopt, Argp, , Parsing Program Arguments -@section Parsing program options using @code{getopt} - -The @code{getopt} and @code{getopt_long} functions automate some of the -chore involved in parsing typical unix command line options. - -@menu -* Using Getopt:: Using the @code{getopt} function. -* Example of Getopt:: An example of parsing options with @code{getopt}. -* Getopt Long Options:: GNU suggests utilities accept long-named - options; here is one way to do. -* Getopt Long Option Example:: An example of using @code{getopt_long}. -@end menu - -@node Using Getopt, Example of Getopt, , Getopt -@subsection Using the @code{getopt} function - -Here are the details about how to call the @code{getopt} function. To -use this facility, your program must include the header file -@file{unistd.h}. -@pindex unistd.h - -@comment unistd.h -@comment POSIX.2 -@deftypevar int opterr -If the value of this variable is nonzero, then @code{getopt} prints an -error message to the standard error stream if it encounters an unknown -option character or an option with a missing required argument. This is -the default behavior. If you set this variable to zero, @code{getopt} -does not print any messages, but it still returns the character @code{?} -to indicate an error. -@end deftypevar - -@comment unistd.h -@comment POSIX.2 -@deftypevar int optopt -When @code{getopt} encounters an unknown option character or an option -with a missing required argument, it stores that option character in -this variable. You can use this for providing your own diagnostic -messages. -@end deftypevar - -@comment unistd.h -@comment POSIX.2 -@deftypevar int optind -This variable is set by @code{getopt} to the index of the next element -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}. -@end deftypevar - -@comment unistd.h -@comment POSIX.2 -@deftypevar {char *} optarg -This variable is set by @code{getopt} to point at the value of the -option argument, for those options that accept arguments. -@end deftypevar - -@comment unistd.h -@comment POSIX.2 -@deftypefun int getopt (int @var{argc}, char *const *@var{argv}, const char *@var{options}) -@safety{@prelim{}@mtunsafe{@mtasurace{:getopt} @mtsenv{}}@asunsafe{@ascuheap{} @ascuintl{} @asulock{} @asucorrupt{}}@acunsafe{@acsmem{} @aculock{} @acucorrupt{}}} -@c Swapping elements of passed-in argv may be partial in case of -@c cancellation. Gettext brings about a whole lot of AS and AC safety -@c issues. The getopt API involves returning values in the -@c non-thread-specific optarg variable, which adds another thread-safety -@c issue. Given print_errors, it may output errors to stderr, which may -@c self-deadlock, leak locks, or encounter (in a signal handler) or -@c leave (in case of cancellation) stderr in an inconsistent state. -@c Various implicit, indirect uses of malloc, in uses of memstream and -@c asprintf for error-printing, bring about the usual malloc issues. -@c -@c _getopt_internal -@c _getopt_internal_r -@c gettext -@c _getopt_initialize -@c getenv -@c open_memstream -@c lockfile, unlockfile, __fxprintf -> stderr -@c asprintf -The @code{getopt} function gets the next option argument from the -argument list specified by the @var{argv} and @var{argc} arguments. -Normally these values come directly from the arguments received by -@code{main}. - -The @var{options} argument is a string that specifies the option -characters that are valid for this program. An option character in this -string can be followed by a colon (@samp{:}) to indicate that it takes a -required argument. If an option character is followed by two colons -(@samp{::}), its argument is optional; this is a GNU extension. - -@code{getopt} has three ways to deal with options that follow -non-options @var{argv} elements. The special argument @samp{--} forces -in all cases the end of option scanning. - -@itemize @bullet -@item -The default is to permute the contents of @var{argv} while scanning it -so that eventually all the non-options are at the end. This allows -options to be given in any order, even with programs that were not -written to expect this. - -@item -If the @var{options} argument string begins with a hyphen (@samp{-}), this -is treated specially. It permits arguments that are not options to be -returned as if they were associated with option character @samp{\1}. - -@item -POSIX demands the following behavior: the first non-option stops option -processing. This mode is selected by either setting the environment -variable @code{POSIXLY_CORRECT} or beginning the @var{options} argument -string with a plus sign (@samp{+}). -@end itemize - -The @code{getopt} function returns the option character for the next -command line option. When no more option arguments are available, it -returns @code{-1}. There may still be more non-option arguments; you -must compare the external variable @code{optind} against the @var{argc} -parameter to check this. - -If the option has an argument, @code{getopt} returns the argument by -storing it in the variable @var{optarg}. You don't ordinarily need to -copy the @code{optarg} string, since it is a pointer into the original -@var{argv} array, not into a static area that might be overwritten. - -If @code{getopt} finds an option character in @var{argv} that was not -included in @var{options}, or a missing option argument, it returns -@samp{?} and sets the external variable @code{optopt} to the actual -option character. If the first character of @var{options} is a colon -(@samp{:}), then @code{getopt} returns @samp{:} instead of @samp{?} to -indicate a missing option argument. In addition, if the external -variable @code{opterr} is nonzero (which is the default), @code{getopt} -prints an error message. -@end deftypefun - -@node Example of Getopt -@subsection Example of Parsing Arguments with @code{getopt} - -Here is an example showing how @code{getopt} is typically used. The -key points to notice are: - -@itemize @bullet -@item -Normally, @code{getopt} is called in a loop. When @code{getopt} returns -@code{-1}, indicating no more options are present, the loop terminates. - -@item -A @code{switch} statement is used to dispatch on the return value from -@code{getopt}. In typical use, each case just sets a variable that -is used later in the program. - -@item -A second loop is used to process the remaining non-option arguments. -@end itemize - -@smallexample -@include testopt.c.texi -@end smallexample - -Here are some examples showing what this program prints with different -combinations of arguments: - -@smallexample -% testopt -aflag = 0, bflag = 0, cvalue = (null) - -% testopt -a -b -aflag = 1, bflag = 1, cvalue = (null) - -% testopt -ab -aflag = 1, bflag = 1, cvalue = (null) - -% testopt -c foo -aflag = 0, bflag = 0, cvalue = foo - -% testopt -cfoo -aflag = 0, bflag = 0, cvalue = foo - -% testopt arg1 -aflag = 0, bflag = 0, cvalue = (null) -Non-option argument arg1 - -% testopt -a arg1 -aflag = 1, bflag = 0, cvalue = (null) -Non-option argument arg1 - -% testopt -c foo arg1 -aflag = 0, bflag = 0, cvalue = foo -Non-option argument arg1 - -% testopt -a -- -b -aflag = 1, bflag = 0, cvalue = (null) -Non-option argument -b - -% testopt -a - -aflag = 1, bflag = 0, cvalue = (null) -Non-option argument - -@end smallexample - -@node Getopt Long Options -@subsection Parsing Long Options with @code{getopt_long} - -To accept GNU-style long options as well as single-character options, -use @code{getopt_long} instead of @code{getopt}. This function is -declared in @file{getopt.h}, not @file{unistd.h}. You should make every -program accept long options if it uses any options, for this takes -little extra work and helps beginners remember how to use the program. - -@comment getopt.h -@comment GNU -@deftp {Data Type} {struct option} -This structure describes a single long option name for the sake of -@code{getopt_long}. The argument @var{longopts} must be an array of -these structures, one for each long option. Terminate the array with an -element containing all zeros. - -The @code{struct option} structure has these fields: - -@table @code -@item const char *name -This field is the name of the option. It is a string. - -@item int has_arg -This field says whether the option takes an argument. It is an integer, -and there are three legitimate values: @w{@code{no_argument}}, -@code{required_argument} and @code{optional_argument}. - -@item int *flag -@itemx int val -These fields control how to report or act on the option when it occurs. - -If @code{flag} is a null pointer, then the @code{val} is a value which -identifies this option. Often these values are chosen to uniquely -identify particular long options. - -If @code{flag} is not a null pointer, it should be the address of an -@code{int} variable which is the flag for this option. The value in -@code{val} is the value to store in the flag to indicate that the option -was seen. -@end table -@end deftp - -@comment getopt.h -@comment GNU -@deftypefun int getopt_long (int @var{argc}, char *const *@var{argv}, const char *@var{shortopts}, const struct option *@var{longopts}, int *@var{indexptr}) -@safety{@prelim{}@mtunsafe{@mtasurace{:getopt} @mtsenv{}}@asunsafe{@ascuheap{} @ascuintl{} @asulock{} @asucorrupt{}}@acunsafe{@acsmem{} @aculock{} @acucorrupt{}}} -@c Same issues as getopt. -Decode options from the vector @var{argv} (whose length is @var{argc}). -The argument @var{shortopts} describes the short options to accept, just as -it does in @code{getopt}. The argument @var{longopts} describes the long -options to accept (see above). - -When @code{getopt_long} encounters a short option, it does the same -thing that @code{getopt} would do: it returns the character code for the -option, and stores the option's argument (if it has one) in @code{optarg}. - -When @code{getopt_long} encounters a long option, it takes actions based -on the @code{flag} and @code{val} fields of the definition of that -option. - -If @code{flag} is a null pointer, then @code{getopt_long} returns the -contents of @code{val} to indicate which option it found. You should -arrange distinct values in the @code{val} field for options with -different meanings, so you can decode these values after -@code{getopt_long} returns. If the long option is equivalent to a short -option, you can use the short option's character code in @code{val}. - -If @code{flag} is not a null pointer, that means this option should just -set a flag in the program. The flag is a variable of type @code{int} -that you define. Put the address of the flag in the @code{flag} field. -Put in the @code{val} field the value you would like this option to -store in the flag. In this case, @code{getopt_long} returns @code{0}. - -For any long option, @code{getopt_long} tells you the index in the array -@var{longopts} of the options definition, by storing it into -@code{*@var{indexptr}}. You can get the name of the option with -@code{@var{longopts}[*@var{indexptr}].name}. So you can distinguish among -long options either by the values in their @code{val} fields or by their -indices. You can also distinguish in this way among long options that -set flags. - -When a long option has an argument, @code{getopt_long} puts the argument -value in the variable @code{optarg} before returning. When the option -has no argument, the value in @code{optarg} is a null pointer. This is -how you can tell whether an optional argument was supplied. - -When @code{getopt_long} has no more options to handle, it returns -@code{-1}, and leaves in the variable @code{optind} the index in -@var{argv} of the next remaining argument. -@end deftypefun - -Since long option names were used before @code{getopt_long} -was invented there are program interfaces which require programs -to recognize options like @w{@samp{-option value}} instead of -@w{@samp{--option value}}. To enable these programs to use the GNU -getopt functionality there is one more function available. - -@comment getopt.h -@comment GNU -@deftypefun int getopt_long_only (int @var{argc}, char *const *@var{argv}, const char *@var{shortopts}, const struct option *@var{longopts}, int *@var{indexptr}) -@safety{@prelim{}@mtunsafe{@mtasurace{:getopt} @mtsenv{}}@asunsafe{@ascuheap{} @ascuintl{} @asulock{} @asucorrupt{}}@acunsafe{@acsmem{} @aculock{} @acucorrupt{}}} -@c Same issues as getopt. - -The @code{getopt_long_only} function is equivalent to the -@code{getopt_long} function but it allows the user of the -application to pass long options with only @samp{-} instead of -@samp{--}. The @samp{--} prefix is still recognized but instead of -looking through the short options if a @samp{-} is seen it is first -tried whether this parameter names a long option. If not, it is parsed -as a short option. - -Assuming @code{getopt_long_only} is used starting an application with - -@smallexample - app -foo -@end smallexample - -@noindent -the @code{getopt_long_only} will first look for a long option named -@samp{foo}. If this is not found, the short options @samp{f}, @samp{o}, -and again @samp{o} are recognized. -@end deftypefun - -@node Getopt Long Option Example -@subsection Example of Parsing Long Options with @code{getopt_long} - -@smallexample -@include longopt.c.texi -@end smallexample |