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(Frodo) Fixed a few spelling errors in the manpage

1 frodo 259 .TH GETOPT 1 "May 31, 1997" Linux ""
2     .SH NAME
3     getopt \- parse command options (enhanced)
4     .SH SYNOPSIS
5     .BR getopt " optstring parameters"
6    
7     .BR getopt " [options] [" \-\- "] optstring parameters"
8    
9     .BR getopt " [options] " \-o | \-\-options " optstring [options] [" \-\- "] parameters"
10     .SH DESCRIPTION
11     .B getopt
12     is used to break up
13     .RI ( parse )
14     options in command lines for easy parsing by
15     shell procedures, and to check for legal options.
16     It uses the
17     .SM GNU
18     .BR getopt (3)
19     routines to do this.
20    
21     The parameters
22     .B getopt
23     is called with can be divided into two parts: options
24     which modify the way getopt will parse
25     .RI ( options
26     and
27     .I \-o|\-\-options optstring
28     in the
29     .BR SYNOPSIS),
30     and the parameters which are to be
31     parsed
32     .RI ( parameters
33     in the
34     .BR SYNOPSIS).
35     The second part will start at the first non\-option parameter
36 frodo 262 that is not an option argument, or after the first occurrence of
37 frodo 259 .RB ` \-\- '.
38     If no
39     .RB ` \-o '
40     or
41     .RB ` \-\-options '
42     option is found in the first part, the first
43     parameter of the second part is used as the short options string.
44    
45     If the environment variable
46     .B GETOPT_COMPATIBLE
47     is set, or if its first parameter
48     is not an option (does not start with a
49     .RB ` \- ',
50     this is the first format in the
51     .BR SYNOPSIS),
52     .B getopt
53     will generate output that is compatible with that of other versions of
54     .BR getopt (1).
55     It will still do parameter shuffling and recognize optional
56     arguments (see section
57     .B COMPATIBILITY
58     for more information).
59    
60     Traditional implementations of
61     .BR getopt (1)
62     are unable to cope with whitespace and other (shell\-specific) special characters
63     in arguments and non\-option parameters. To solve this problem, this
64     implementation can generate
65     quoted output which must once again be interpreted by the shell (usually
66     by using the
67     .B eval
68     command). This has the effect of preserving those characters, but
69     you must call
70     .B getopt
71     in a way that is no longer compatible with other versions (the second
72     or third format in the
73     .BR SYNOPSIS).
74     To determine whether this enhanced version of
75     .BR getopt (1)
76     is installed, a special test option
77     .RB ( \-T )
78     can be used.
79     .SH OPTIONS
80     .IP "\-a, \-\-alternative"
81     Allow long options to start with a single
82     .RB ` \- '.
83     .IP "\-h, \-\-help"
84     Output a small usage guide and exit succesfully. No other output is generated.
85     .IP "\-l, \-\-longoptions longopts"
86     The long (multi\-character) options to be recognized.
87     More than one option name
88     may be specified at once, by separating the names with commas. This option
89     may be given more than once, the
90     .I longopts
91     are cumulative.
92     Each long option name
93     in
94     .I longopts
95     may be followed by one colon to indicate it has a required argument,and by two colons to indicate it has an optional argument.
96     .IP "\-n, \-\-name progname"
97     The name that will be used by the
98     .BR getopt (3)
99     routines when it reports errors. Note that errors of
100     .BR getopt (1)
101     are still reported as coming from getopt.
102     .IP "\-o, \-\-options shortopts"
103 frodo 262 The short (one\-character) options to be recognized. If this option is not
104 frodo 259 found, the first parameter of
105     .B getopt
106     that does not start with
107     a
108     .RB ` \- '
109     (and is not an option argument) is used as the short options string.
110     Each short option character
111     in
112     .I shortopts
113     may be followed by one colon to indicate it has a required argument,
114     and by two colons to indicate it has an optional argument.
115     The first character of shortopts may be
116     .RB ` + '
117     or
118     .RB ` \- '
119     to influence the way
120     options are parsed and output is generated (see section
121     .B SCANNING MODES
122     for details).
123     .IP "\-q, \-\-quiet"
124     Disable error reporting by getopt(3).
125     .IP "\-Q, \-\-quiet\-output"
126     Do not generate normal output. Errors are still reported by
127     .BR getopt (3),
128     unless you also use
129     .IR \-q .
130     .IP "\-s, \-\-shell shell"
131     Set quoting conventions to those of shell. If no \-s argument is found,
132     the
133     .SM BASH
134     conventions are used. Valid arguments are currently
135     .RB ` sh '
136     .RB ` bash ',
137     .RB ` csh ',
138     and
139     .RB ` tcsh '.
140     .IP "\-u, \-\-unquoted"
141     Do not quote the output. Note that whitespace and special (shell\-dependent)
142     characters can cause havoc in this mode (like they do with other
143     .BR getopt (1)
144     implementations).
145     .IP "\-T \-\-test"
146     Test if your
147     .BR getopt (1)
148     is this enhanced version or an old version. This generates no output,
149     and sets the error status to 4. Other implementations of
150     .BR getopt (1),
151     and this version if the environment variable
152     .B GETOPT_COMPATIBLE
153     is set,
154     will return
155     .RB ` \-\- '
156     and error status 0.
157     .IP "\-V, \-\-version"
158     Output version information and exit succesfully. No other output is generated.
159     .SH PARSING
160     This section specifies the format of the second part of the parameters of
161     .B getopt
162     (the
163     .I parameters
164     in the
165     .BR SYNOPSIS ).
166     The next section
167     .RB ( OUTPUT )
168     describes the output that is
169     generated. These parameters were typically the parameters a shell function
170     was called with.
171     Care must be taken that each parameter the shell function was
172     called with corresponds to exactly one parameter in the parameter list of
173     .B getopt
174     (see the
175     .BR EXAMPLES ).
176     All parsing is done by the GNU
177     .BR getopt (3)
178     routines.
179    
180     The parameters are parsed from left to right. Each parameter is classified as a
181     short option, a long option, an argument to an option,
182     or a non\-option parameter.
183    
184     A simple short option is a
185     .RB ` \- '
186     followed by a short option character. If
187     the option has a required argument, it may be written directly after the option
188     character or as the next parameter (ie. separated by whitespace on the
189     command line). If the
190     option has an optional argument, it must be written directly after the
191     option character if present.
192    
193     It is possible to specify several short options after one
194     .RB ` \- ',
195     as long as all (except possibly the last) do not have required or optional
196     arguments.
197    
198     A long option normally begins with
199     .RB ` \-\- '
200     followed by the long option name.
201     If the option has a required argument, it may be written directly after
202     the long option name, separated by
203     .RB ` = ',
204     or as the next argument (ie. separated by whitespace on the command line).
205     If the option has an optional argument, it must
206     be written directly after the long option name, separated by
207     .RB ` = ',
208     if present (if you add the
209     .RB ` = '
210     but nothing behind it, it is interpreted
211     as if no argument was present; this is a slight bug, see the
212     .BR BUGS ).
213     Long options may be abbreviated, as long as the abbreviation is not
214     ambiguous.
215    
216     Each parameter not starting with a
217     .RB ` \- ',
218     and not a required argument of
219     a previous option, is a non\-option parameter. Each parameter after
220     a
221     .RB ` \-\- '
222     parameter is always interpreted as a non\-option parameter.
223     If the environment variable
224     .B POSIXLY_CORRECT
225     is set, or if the short
226     option string started with a
227     .RB ` + ',
228     all remaining parameters are interpreted
229     as non\-option parameters as soon as the first non\-option parameter is
230     found.
231     .SH OUTPUT
232     Output is generated for each element described in the previous section.
233     Output is done
234     in the same order as the elements are specified in the input, except
235     for non\-option parameters. Output can be done in
236     .I compatible
237     .RI ( unquoted )
238     mode, or in such way that whitespace and other special characters within
239     arguments and non\-option parameters are preserved (see
240     .BR QUOTING ).
241     When the output is processed in the shell script, it will seem to be
242     composed of distinct elements that can be processed one by one (by using the
243     shift command in most shell languages). This is imperfect in unquoted mode,
244     as elements can be split at unexpected places if they contain whitespace
245     or special characters.
246    
247     If there are problems parsing the parameters, for example because a
248     required argument is not found or an option is not recognized, an error
249     will be reported on stderr, there will be no output for the offending
250     element, and a non\-zero error status is returned.
251    
252     For a short option, a single
253     .RB ` \- '
254     and the option character are generated
255     as one parameter. If the option has an argument, the next
256     parameter will be the argument. If the option takes an optional argument,
257     but none was found, the next parameter will be generated but be empty in
258     quoting mode,
259     but no second parameter will be generated in unquoted (compatible) mode.
260     Note that many other
261     .BR getopt (1)
262     implemetations do not support optional arguments.
263    
264     If several short options were specified after a single
265     .RB ` \- ',
266     each will be present in the output as a separate parameter.
267    
268     For a long option,
269     .RB ` \-\- '
270     and the full option name are generated as one
271     parameter. This is done regardless whether the option was abbreviated or
272     specified with a single
273     .RB ` \- '
274     in the input. Arguments are handled as with short options.
275    
276     Normally, no non\-option parameters output is generated until all options
277     and their arguments have been generated. Then
278     .RB ` \-\- '
279     is generated as a
280     single parameter, and after it the non\-option parameters in the order
281     they were found, each as a separate parameter.
282     Only if the first character of the short options string was a
283     .RB ` \- ',
284     non\-option parameter output is generated at the place they are found in the
285     input (this is not supported if the first format of the
286     .B SYNOPSIS
287 frodo 262 is used; in that case all preceding occurrences of
288 frodo 259 .RB ` \- '
289     and
290     .RB ` + '
291     are ignored).
292     .SH QUOTING
293     In compatible mode, whitespace or 'special' characters in arguments or
294     non\-option parameters are not handled correctly. As the output is
295     fed to the shell script, the script does not know how it is supposed to break
296     the output into separate parameters. To circumvent this
297     problem, this implementation offers quoting. The idea is that output
298     is generated with quotes around each parameter. When this output is once
299     again fed to the shell (usually by a shell
300     .B eval
301     command), it is split correctly into separate parameters.
302    
303     Quoting is not enabled if the environment variable
304     .B GETOPT_COMPATIBLE
305     is set, if the first form of the
306     .B SYNOPSIS
307     is used, or if the option
308     .RB ` \-u '
309     is found.
310    
311     Different shells use different quoting conventions. You can use the
312     .RB ` \-s '
313     option to select the shell you are using. The following shells are
314     currently supported:
315     .RB ` sh ',
316     .RB ` bash ',
317     .RB ` csh '
318     and
319     .RB ` tcsh '.
320     Actually, only two `flavors' are distinguished: sh\-like quoting conventions
321     and csh\-like quoting conventions. Chances are that if you use another shell
322     script language, one of these flavors can still be used.
323    
324     .SH "SCANNING MODES"
325     The first character of the short options string may be a
326     .RB ` \- '
327     or a
328     .RB ` + '
329     to indicate a special scanning mode. If the first calling form
330     in the
331     .B SYNOPSIS
332     is used they are ignored; the environment variable
333     .B POSIXLY_CORRECT
334     is still examined, though.
335    
336     If the first character is
337     .RB ` + ',
338     or if the environment variable
339     .B POSIXLY_CORRECT
340     is set, parsing stops as soon as the first non\-option parameter
341     (ie. a parameter that does not start with a
342     .RB ` \- ')
343     is found that
344     is not an option argument. The remaining parameters are all interpreted as
345     non\-option parameters.
346    
347     If the first character is a
348     .RB ` \- ',
349     non\-option parameters are outputed at the place where they are found; in normal
350     operation, they are all collected at the end of output after a
351     .RB ` \-\- '
352     parameter has been generated. Note that this
353     .RB ` \-\- '
354     parameter is still generated, but it will always be the last parameter in
355     this mode.
356     .SH COMPATIBILITY
357     This version of
358     .BR getopt (1)
359     is written to be as compatible as possible to
360     other versions. Usually you can just replace them with this version
361     without any modifications, and with some advantages.
362    
363     If the first character of the first parameter of getopt is not a
364     .RB ` \- ',
365     getopt goes into compatibility mode. It will interpret its first parameter as
366     the string of short options, and all other arguments will be parsed. It
367     will still do parameter shuffling (ie. all non\-option parameters are outputed
368     at the end), unless the environment variable
369     .B POSIXLY_CORRECT
370     is set.
371    
372     The environment variable
373     .B GETOPT_COMPATIBLE
374     forces
375     .B getopt
376     into compatibility mode. Setting both this environment variable and
377     .B POSIXLY_CORRECT
378     offers 100% compatibility for `difficult' programs. Usually, though,
379     neither is needed.
380    
381     In compatibility mode, leading
382     .RB ` \- '
383     and
384     .RB ` + '
385     characters in the short options string are ignored.
386     .SH RETURN CODES
387     .B getopt
388     returns error code
389     .B 0
390     for succesful parsing,
391     .B 1
392     if
393     .BR getopt (3)
394     returns errors,
395     .B 2
396     if it does not understand its own parameters,
397     .B 3
398     if an internal error occurs like out\-of\-memory, and
399     .B 4
400     if it is called with
401     .BR \-T .
402     .SH EXAMPLES
403     Example scripts for (ba)sh and (t)csh are provided with the
404     .BR getopt (1)
405     distribution, and are optionally installed in
406     .B /usr/local/lib/getopt
407     or
408     .BR /usr/lib/getopt .
409     .SH ENVIRONMENT
410     .IP POSIXLY_CORRECT
411     This environment variable is examined by the
412     .BR getopt (3)
413     routines.
414     If it is set, parsing stops as soon as a parameter
415     is found that is not an option or an option argument. All remaining
416     parameters are also interpreted as non\-option parameters, regardless
417     whether they start with a
418     .RB ` \- '.
419     .IP GETOPT_COMPATIBLE
420     Forces
421     .B getopt
422     to use the first calling format as specified in the
423     .BR SYNOPSIS .
424     .SH BUGS
425     .BR getopt (3)
426     can parse long options with optional arguments that are given an empty optional
427     argument (but can not do this for short options). This
428     .BR getopt (1)
429     treats optional arguments that are empty as if they were not present.
430    
431     The syntax if you do not want any short option variables at all is
432     not very intuitive (you have to set them explicitely to the empty
433     string).
434    
435     .SH AUTHOR
436     Frodo Looijaard <frodol@dds.nl>
437     .SH "SEE ALSO"
438     .BR getopt (3),
439     .BR bash (1),
440     .BR tcsh (1).
441    

frodo@frodo.looijaard.name
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