diff options
Diffstat (limited to 'lib/libc/stdlib/getopt_long.3')
| -rw-r--r-- | lib/libc/stdlib/getopt_long.3 | 400 |
1 files changed, 400 insertions, 0 deletions
diff --git a/lib/libc/stdlib/getopt_long.3 b/lib/libc/stdlib/getopt_long.3 new file mode 100644 index 0000000..9f46bff --- /dev/null +++ b/lib/libc/stdlib/getopt_long.3 @@ -0,0 +1,400 @@ +.\" $NetBSD: getopt_long.3,v 1.8 2002/06/03 12:01:43 wiz Exp $ +.\" +.\" Copyright (c) 1988, 1991, 1993 +.\" The Regents of the University of California. All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" 3. All advertising materials mentioning features or use of this software +.\" must display the following acknowledgement: +.\" This product includes software developed by the University of +.\" California, Berkeley and its contributors. +.\" 4. Neither the name of the University nor the names of its contributors +.\" may be used to endorse or promote products derived from this software +.\" without specific prior written permission. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.\" @(#)getopt.3 8.5 (Berkeley) 4/27/95 +.\" $FreeBSD$ +.\" +.Dd April 1, 2000 +.Dt GETOPT_LONG 3 +.Os +.Sh NAME +.Nm getopt_long +.Nd get long options from command line argument list +.Sh LIBRARY +.Lb libc +.Sh SYNOPSIS +.In getopt.h +.Ft int +.Fo getopt_long +.Fa "int argc" "char * const *argv" "const char *optstring" +.Fa "struct option *long options" "int *index" +.Fc +.Sh DESCRIPTION +The +.Fn getopt_long +function is similar to +.Xr getopt 3 +but it accepts options in two forms: words and characters. +The +.Fn getopt_long +function provides a superset of the functionality of +.Xr getopt 3 . +The +.Fn getopt_long +function +can be used in two ways. +In the first way, every long option understood +by the program has a corresponding short option, and the option +structure is only used to translate from long options to short +options. +When used in this fashion, +.Fn getopt_long +behaves identically to +.Xr getopt 3 . +This is a good way to add long option processing to an existing program +with the minimum of rewriting. +.Pp +In the second mechanism, a long option sets a flag in the +.Vt option +structure passed, or will store a pointer to the command line argument +in the +.Vt option +structure passed to it for options that take arguments. +Additionally, +the long option's argument may be specified as a single argument with +an equal sign, e.g., +.Pp +.Dl "myprogram --myoption=somevalue" +.Pp +When a long option is processed, the call to +.Fn getopt_long +will return 0. +For this reason, long option processing without +shortcuts is not backwards compatible with +.Xr getopt 3 . +.Pp +It is possible to combine these methods, providing for long options +processing with short option equivalents for some options. +Less +frequently used options would be processed as long options only. +.Pp +The +.Fn getopt_long +call requires a structure to be initialized describing the long +options. +The structure is: +.Bd -literal -offset indent +struct option { + char *name; + int has_arg; + int *flag; + int val; +}; +.Ed +.Pp +The +.Va name +field should contain the option name without the leading double dash. +.Pp +The +.Va has_arg +field should be one of: +.Pp +.Bl -tag -width ".Dv optional_argument" -offset indent -compact +.It Dv no_argument +no argument to the option is expect +.It Dv required_argument +an argument to the option is required +.It Li optional_argument +an argument to the option may be presented. +.El +.Pp +If +.Va flag +is not +.Dv NULL , +then the integer pointed to by it will be set to the +value in the +.Va val +field. +If the +.Va flag +field is +.Dv NULL , +then the +.Va val +field will be returned. +Setting +.Va flag +to +.Dv NULL +and setting +.Va val +to the corresponding short option will make this function act just +like +.Xr getopt 3 . +.Sh EXAMPLES +.Bd -literal -compact +extern char *optarg; +extern int optind; +int bflag, ch, fd; +int daggerset; + +/* options descriptor */ +static struct option longopts[] = { + { "buffy", no_argument, 0, 'b' }, + { "floride", required_argument, 0, 'f' }, + { "daggerset", no_argument, \*[Am]daggerset, 1 }, + { 0, 0, 0, 0 } +}; + +bflag = 0; +while ((ch = getopt_long(argc, argv, "bf:", longopts, NULL)) != -1) + switch(ch) { + case 'b': + bflag = 1; + break; + case 'f': + if ((fd = open(optarg, O_RDONLY, 0)) \*[Lt] 0) { + (void)fprintf(stderr, + "myname: %s: %s\en", optarg, strerror(errno)); + exit(1); + } + break; + case 0: + if(daggerset) { + fprintf(stderr,"Buffy will use her dagger to " + "apply floride to dracula's teeth\en"); + } + break; + case '?': + default: + usage(); +} +argc -= optind; +argv += optind; +.Ed +.Sh IMPLEMENTATION DIFFERENCES +This section describes differences to the +.Tn GNU +implementation +found in glibc-2.1.3: +.Bl -bullet +.It +Handling of +.Ql - +as first char of option string in presence of +environment variable +.Ev POSIXLY_CORRECT : +.Bl -tag -width ".Nx" +.It Tn GNU +ignores +.Ev POSIXLY_CORRECT +and returns non-options as +arguments to option '\e1'. +.It Nx +honors +.Ev POSIXLY_CORRECT +and stops at the first non-option. +.El +.It +Handling of +.Ql :: +in options string in presence of +.Ev POSIXLY_CORRECT : +.Bl -tag -width ".Nx" +.It Both +.Tn GNU +and +.Nx +ignore +.Ev POSIXLY_CORRECT +here and take +.Ql :: +to +mean the preceding option takes an optional argument. +.El +.It +Return value in case of missing argument if first character +(after +.Ql + +or +.Ql - ) +in option string is not +.Ql \&: : +.Bl -tag -width ".Nx" +.It Tn GNU +returns +.Ql \&? +.It Nx +returns +.Ql \&: +(since +.Nx Ns 's +.Fn getopt +does). +.El +.It +Handling of +.Ql --a +in getopt: +.Bl -tag -width ".Nx" +.It Tn GNU +parses this as option +.Ql - , +option +.Ql a . +.It Nx +parses this as +.Ql -- , +and returns \-1 (ignoring the +.Ql a ) . +(Because the original +.Fn getopt +does.) +.El +.It +Setting of +.Va optopt +for long options with +.Va flag +!= +.Dv NULL : +.Bl -tag -width ".Nx" +.It Tn GNU +sets +.Va optopt +to +.Va val . +.It Nx +sets +.Va optopt +to 0 (since +.Va val +would never be returned). +.El +.It +Handling of +.Ql -W +with +.Ql W ; +in option string in +.Fn getopt +(not +.Fn getopt_long ) : +.Bl -tag -width ".Nx" +.It Tn GNU +causes a segfault. +.It Nx +returns \-1, with +.Va optind +pointing past the argument of +.Ql -W +(as if +.Ql "-W arg" +were +.Ql --arg , +and thus +.Ql -- +had been found). +.\" How should we treat W; in the option string when called via +.\" getopt? Ignore the ';' or treat it as a ':'? Issue a warning? +.El +.It +Setting of +.Va optarg +for long options without an argument that are +invoked via +.Ql -W +.Ql ( W ; +in option string): +.Bl -tag -width ".Nx" +.It Tn GNU +sets +.Va optarg +to the option name (the argument of +.Ql -W ) . +.It Nx +sets +.Va optarg +to +.Dv NULL +(the argument of the long option). +.El +.It +Handling of +.Ql -W +with an argument that is not (a prefix to) a known +long option +.Ql ( W ; +in option string): +.Bl -tag -width ".Nx" +.It Tn GNU +returns +.Ql -W +with +.Va optarg +set to the unknown option. +.It Nx +treats this as an error (unknown option) and returns +.Ql \&? +with +.Va optopt +set to 0 and +.Va optarg +set to +.Dv NULL +(as +.Tn GNU Ns 's +man page documents). +.El +.It +The error messages are different. +.It +.Nx +does not permute the argument vector at the same points in +the calling sequence as +.Tn GNU +does. +The aspects normally used by +the caller (ordering after \-1 is returned, value of +.Va optind +relative +to current positions) are the same, though. +(We do fewer variable swaps.) +.El +.Sh SEE ALSO +.Xr getopt 3 +.Sh HISTORY +The +.Fn getopt_long +function first appeared in +.Tn GNU +libiberty. +The first +.Nx +implementation appeared in 1.5. +.Sh BUGS +The implementation can completely replace +.Xr getopt 3 , +but right now we are using separate code. |
