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tagged 'mkinitrd-6_2_1'
1 | Busybox Style Guide |
2 | =================== |
3 | |
4 | This document describes the coding style conventions used in Busybox. If you |
5 | add a new file to Busybox or are editing an existing file, please format your |
6 | code according to this style. If you are the maintainer of a file that does |
7 | not follow these guidelines, please -- at your own convenience -- modify the |
8 | file(s) you maintain to bring them into conformance with this style guide. |
9 | Please note that this is a low priority task. |
10 | |
11 | To help you format the whitespace of your programs, an ".indent.pro" file is |
12 | included in the main Busybox source directory that contains option flags to |
13 | format code as per this style guide. This way you can run GNU indent on your |
14 | files by typing 'indent myfile.c myfile.h' and it will magically apply all the |
15 | right formatting rules to your file. Please _do_not_ run this on all the files |
16 | in the directory, just your own. |
17 | |
18 | |
19 | |
20 | Declaration Order |
21 | ----------------- |
22 | |
23 | Here is the preferred order in which code should be laid out in a file: |
24 | |
25 | - commented program name and one-line description |
26 | - commented author name and email address(es) |
27 | - commented GPL boilerplate |
28 | - commented longer description / notes for the program (if needed) |
29 | - #includes of .h files with angle brackets (<>) around them |
30 | - #includes of .h files with quotes ("") around them |
31 | - #defines (if any, note the section below titled "Avoid the Preprocessor") |
32 | - const and global variables |
33 | - function declarations (if necessary) |
34 | - function implementations |
35 | |
36 | |
37 | |
38 | Whitespace and Formatting |
39 | ------------------------- |
40 | |
41 | This is everybody's favorite flame topic so let's get it out of the way right |
42 | up front. |
43 | |
44 | |
45 | Tabs vs. Spaces in Line Indentation |
46 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
47 | |
48 | The preference in Busybox is to indent lines with tabs. Do not indent lines |
49 | with spaces and do not indents lines using a mixture of tabs and spaces. (The |
50 | indentation style in the Apache and Postfix source does this sort of thing: |
51 | \s\s\s\sif (expr) {\n\tstmt; --ick.) The only exception to this rule is |
52 | multi-line comments that use an asterisk at the beginning of each line, i.e.: |
53 | |
54 | \t/* |
55 | \t * This is a block comment. |
56 | \t * Note that it has multiple lines |
57 | \t * and that the beginning of each line has a tab plus a space |
58 | \t * except for the opening '/*' line where the slash |
59 | \t * is used instead of a space. |
60 | \t */ |
61 | |
62 | Furthermore, The preference is that tabs be set to display at four spaces |
63 | wide, but the beauty of using only tabs (and not spaces) at the beginning of |
64 | lines is that you can set your editor to display tabs at *whatever* number of |
65 | spaces is desired and the code will still look fine. |
66 | |
67 | |
68 | Operator Spacing |
69 | ~~~~~~~~~~~~~~~~ |
70 | |
71 | Put spaces between terms and operators. Example: |
72 | |
73 | Don't do this: |
74 | |
75 | for(i=0;i<num_items;i++){ |
76 | |
77 | Do this instead: |
78 | |
79 | for (i = 0; i < num_items; i++) { |
80 | |
81 | While it extends the line a bit longer, the spaced version is more |
82 | readable. An allowable exception to this rule is the situation where |
83 | excluding the spacing makes it more obvious that we are dealing with a |
84 | single term (even if it is a compound term) such as: |
85 | |
86 | if (str[idx] == '/' && str[idx-1] != '\\') |
87 | |
88 | or |
89 | |
90 | if ((argc-1) - (optind+1) > 0) |
91 | |
92 | |
93 | Bracket Spacing |
94 | ~~~~~~~~~~~~~~~ |
95 | |
96 | If an opening bracket starts a function, it should be on the |
97 | next line with no spacing before it. However, if a bracket follows an opening |
98 | control block, it should be on the same line with a single space (not a tab) |
99 | between it and the opening control block statement. Examples: |
100 | |
101 | Don't do this: |
102 | |
103 | while (!done) |
104 | { |
105 | |
106 | do |
107 | { |
108 | |
109 | Don't do this either: |
110 | |
111 | while (!done){ |
112 | |
113 | do{ |
114 | |
115 | And for heaven's sake, don't do this: |
116 | |
117 | while (!done) |
118 | { |
119 | |
120 | do |
121 | { |
122 | |
123 | Do this instead: |
124 | |
125 | while (!done) { |
126 | |
127 | do { |
128 | |
129 | If you have long logic statements that need to be wrapped, then uncuddling |
130 | the bracket to improve readability is allowed. Generally, this style makes |
131 | it easier for reader to notice that 2nd and following lines are still |
132 | inside 'if': |
133 | |
134 | if (some_really_long_checks && some_other_really_long_checks |
135 | && some_more_really_long_checks |
136 | && even_more_of_long_checks |
137 | ) { |
138 | do_foo_now; |
139 | |
140 | Spacing around Parentheses |
141 | ~~~~~~~~~~~~~~~~~~~~~~~~~~ |
142 | |
143 | Put a space between C keywords and left parens, but not between function names |
144 | and the left paren that starts it's parameter list (whether it is being |
145 | declared or called). Examples: |
146 | |
147 | Don't do this: |
148 | |
149 | while(foo) { |
150 | for(i = 0; i < n; i++) { |
151 | |
152 | Do this instead: |
153 | |
154 | while (foo) { |
155 | for (i = 0; i < n; i++) { |
156 | |
157 | But do functions like this: |
158 | |
159 | static int my_func(int foo, char bar) |
160 | ... |
161 | baz = my_func(1, 2); |
162 | |
163 | Also, don't put a space between the left paren and the first term, nor between |
164 | the last arg and the right paren. |
165 | |
166 | Don't do this: |
167 | |
168 | if ( x < 1 ) |
169 | strcmp( thisstr, thatstr ) |
170 | |
171 | Do this instead: |
172 | |
173 | if (x < 1) |
174 | strcmp(thisstr, thatstr) |
175 | |
176 | |
177 | Cuddled Elses |
178 | ~~~~~~~~~~~~~ |
179 | |
180 | Also, please "cuddle" your else statements by putting the else keyword on the |
181 | same line after the right bracket that closes an 'if' statement. |
182 | |
183 | Don't do this: |
184 | |
185 | if (foo) { |
186 | stmt; |
187 | } |
188 | else { |
189 | stmt; |
190 | } |
191 | |
192 | Do this instead: |
193 | |
194 | if (foo) { |
195 | stmt; |
196 | } else { |
197 | stmt; |
198 | } |
199 | |
200 | The exception to this rule is if you want to include a comment before the else |
201 | block. Example: |
202 | |
203 | if (foo) { |
204 | stmts... |
205 | } |
206 | /* otherwise, we're just kidding ourselves, so re-frob the input */ |
207 | else { |
208 | other_stmts... |
209 | } |
210 | |
211 | |
212 | Labels |
213 | ~~~~~~ |
214 | |
215 | Labels should start at the beginning of the line, not indented to the block |
216 | level (because they do not "belong" to block scope, only to whole function). |
217 | |
218 | if (foo) { |
219 | stmt; |
220 | label: |
221 | stmt2; |
222 | stmt; |
223 | } |
224 | |
225 | (Putting label at position 1 prevents diff -p from confusing label for function |
226 | name, but it's not a policy of busybox project to enforce such a minor detail). |
227 | |
228 | |
229 | |
230 | Variable and Function Names |
231 | --------------------------- |
232 | |
233 | Use the K&R style with names in all lower-case and underscores occasionally |
234 | used to separate words (e.g., "variable_name" and "numchars" are both |
235 | acceptable). Using underscores makes variable and function names more readable |
236 | because it looks like whitespace; using lower-case is easy on the eyes. |
237 | |
238 | Frowned upon: |
239 | |
240 | hitList |
241 | TotalChars |
242 | szFileName |
243 | pf_Nfol_TriState |
244 | |
245 | Preferred: |
246 | |
247 | hit_list |
248 | total_chars |
249 | file_name |
250 | sensible_name |
251 | |
252 | Exceptions: |
253 | |
254 | - Enums, macros, and constant variables are occasionally written in all |
255 | upper-case with words optionally separated by underscores (i.e. FIFO_TYPE, |
256 | ISBLKDEV()). |
257 | |
258 | - Nobody is going to get mad at you for using 'pvar' as the name of a |
259 | variable that is a pointer to 'var'. |
260 | |
261 | |
262 | Converting to K&R |
263 | ~~~~~~~~~~~~~~~~~ |
264 | |
265 | The Busybox codebase is very much a mixture of code gathered from a variety of |
266 | sources. This explains why the current codebase contains such a hodge-podge of |
267 | different naming styles (Java, Pascal, K&R, just-plain-weird, etc.). The K&R |
268 | guideline explained above should therefore be used on new files that are added |
269 | to the repository. Furthermore, the maintainer of an existing file that uses |
270 | alternate naming conventions should, at his own convenience, convert those |
271 | names over to K&R style. Converting variable names is a very low priority |
272 | task. |
273 | |
274 | If you want to do a search-and-replace of a single variable name in different |
275 | files, you can do the following in the busybox directory: |
276 | |
277 | $ perl -pi -e 's/\bOldVar\b/new_var/g' *.[ch] |
278 | |
279 | If you want to convert all the non-K&R vars in your file all at once, follow |
280 | these steps: |
281 | |
282 | - In the busybox directory type 'examples/mk2knr.pl files-to-convert'. This |
283 | does not do the actual conversion, rather, it generates a script called |
284 | 'convertme.pl' that shows what will be converted, giving you a chance to |
285 | review the changes beforehand. |
286 | |
287 | - Review the 'convertme.pl' script that gets generated in the busybox |
288 | directory and remove / edit any of the substitutions in there. Please |
289 | especially check for false positives (strings that should not be |
290 | converted). |
291 | |
292 | - Type './convertme.pl same-files-as-before' to perform the actual |
293 | conversion. |
294 | |
295 | - Compile and see if everything still works. |
296 | |
297 | Please be aware of changes that have cascading effects into other files. For |
298 | example, if you're changing the name of something in, say utility.c, you |
299 | should probably run 'examples/mk2knr.pl utility.c' at first, but when you run |
300 | the 'convertme.pl' script you should run it on _all_ files like so: |
301 | './convertme.pl *.[ch]'. |
302 | |
303 | |
304 | |
305 | Avoid The Preprocessor |
306 | ---------------------- |
307 | |
308 | At best, the preprocessor is a necessary evil, helping us account for platform |
309 | and architecture differences. Using the preprocessor unnecessarily is just |
310 | plain evil. |
311 | |
312 | |
313 | The Folly of #define |
314 | ~~~~~~~~~~~~~~~~~~~~ |
315 | |
316 | Use 'const <type> var' for declaring constants. |
317 | |
318 | Don't do this: |
319 | |
320 | #define CONST 80 |
321 | |
322 | Do this instead, when the variable is in a header file and will be used in |
323 | several source files: |
324 | |
325 | enum { CONST = 80 }; |
326 | |
327 | Although enum may look ugly to some people, it is better for code size. |
328 | With "const int" compiler may fail to optimize it out and will reserve |
329 | a real storage in rodata for it! (Hopefully, newer gcc will get better |
330 | at it...). With "define", you have slight risk of polluting namespace |
331 | (#define doesn't allow you to redefine the name in the inner scopes), |
332 | and complex "define" are evaluated each time they uesd, not once |
333 | at declarations like enums. Also, the preprocessor does _no_ type checking |
334 | whatsoever, making it much more error prone. |
335 | |
336 | |
337 | The Folly of Macros |
338 | ~~~~~~~~~~~~~~~~~~~ |
339 | |
340 | Use 'static inline' instead of a macro. |
341 | |
342 | Don't do this: |
343 | |
344 | #define mini_func(param1, param2) (param1 << param2) |
345 | |
346 | Do this instead: |
347 | |
348 | static inline int mini_func(int param1, param2) |
349 | { |
350 | return (param1 << param2); |
351 | } |
352 | |
353 | Static inline functions are greatly preferred over macros. They provide type |
354 | safety, have no length limitations, no formatting limitations, have an actual |
355 | return value, and under gcc they are as cheap as macros. Besides, really long |
356 | macros with backslashes at the end of each line are ugly as sin. |
357 | |
358 | |
359 | The Folly of #ifdef |
360 | ~~~~~~~~~~~~~~~~~~~ |
361 | |
362 | Code cluttered with ifdefs is difficult to read and maintain. Don't do it. |
363 | Instead, put your ifdefs at the top of your .c file (or in a header), and |
364 | conditionally define 'static inline' functions, (or *maybe* macros), which are |
365 | used in the code. |
366 | |
367 | Don't do this: |
368 | |
369 | ret = my_func(bar, baz); |
370 | if (!ret) |
371 | return -1; |
372 | #ifdef CONFIG_FEATURE_FUNKY |
373 | maybe_do_funky_stuff(bar, baz); |
374 | #endif |
375 | |
376 | Do this instead: |
377 | |
378 | (in .h header file) |
379 | |
380 | #if ENABLE_FEATURE_FUNKY |
381 | static inline void maybe_do_funky_stuff(int bar, int baz) |
382 | { |
383 | /* lotsa code in here */ |
384 | } |
385 | #else |
386 | static inline void maybe_do_funky_stuff(int bar, int baz) {} |
387 | #endif |
388 | |
389 | (in the .c source file) |
390 | |
391 | ret = my_func(bar, baz); |
392 | if (!ret) |
393 | return -1; |
394 | maybe_do_funky_stuff(bar, baz); |
395 | |
396 | The great thing about this approach is that the compiler will optimize away |
397 | the "no-op" case (the empty function) when the feature is turned off. |
398 | |
399 | Note also the use of the word 'maybe' in the function name to indicate |
400 | conditional execution. |
401 | |
402 | |
403 | |
404 | Notes on Strings |
405 | ---------------- |
406 | |
407 | Strings in C can get a little thorny. Here's some guidelines for dealing with |
408 | strings in Busybox. (There is surely more that could be added to this |
409 | section.) |
410 | |
411 | |
412 | String Files |
413 | ~~~~~~~~~~~~ |
414 | |
415 | Put all help/usage messages in usage.c. Put other strings in messages.c. |
416 | Putting these strings into their own file is a calculated decision designed to |
417 | confine spelling errors to a single place and aid internationalization |
418 | efforts, if needed. (Side Note: we might want to use a single file - maybe |
419 | called 'strings.c' - instead of two, food for thought). |
420 | |
421 | |
422 | Testing String Equivalence |
423 | ~~~~~~~~~~~~~~~~~~~~~~~~~~ |
424 | |
425 | There's a right way and a wrong way to test for sting equivalence with |
426 | strcmp(): |
427 | |
428 | The wrong way: |
429 | |
430 | if (!strcmp(string, "foo")) { |
431 | ... |
432 | |
433 | The right way: |
434 | |
435 | if (strcmp(string, "foo") == 0){ |
436 | ... |
437 | |
438 | The use of the "equals" (==) operator in the latter example makes it much more |
439 | obvious that you are testing for equivalence. The former example with the |
440 | "not" (!) operator makes it look like you are testing for an error. In a more |
441 | perfect world, we would have a streq() function in the string library, but |
442 | that ain't the world we're living in. |
443 | |
444 | |
445 | Avoid Dangerous String Functions |
446 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
447 | |
448 | Unfortunately, the way C handles strings makes them prone to overruns when |
449 | certain library functions are (mis)used. The following table offers a summary |
450 | of some of the more notorious troublemakers: |
451 | |
452 | function overflows preferred |
453 | ------------------------------------------------- |
454 | strcpy dest string safe_strncpy |
455 | strncpy may fail to 0-terminate dst safe_strncpy |
456 | strcat dest string strncat |
457 | gets string it gets fgets |
458 | getwd buf string getcwd |
459 | [v]sprintf str buffer [v]snprintf |
460 | realpath path buffer use with pathconf |
461 | [vf]scanf its arguments just avoid it |
462 | |
463 | |
464 | The above is by no means a complete list. Be careful out there. |
465 | |
466 | |
467 | |
468 | Avoid Big Static Buffers |
469 | ------------------------ |
470 | |
471 | First, some background to put this discussion in context: static buffers look |
472 | like this in code: |
473 | |
474 | /* in a .c file outside any functions */ |
475 | static char buffer[BUFSIZ]; /* happily used by any function in this file, |
476 | but ick! big! */ |
477 | |
478 | The problem with these is that any time any busybox app is run, you pay a |
479 | memory penalty for this buffer, even if the applet that uses said buffer is |
480 | not run. This can be fixed, thusly: |
481 | |
482 | static char *buffer; |
483 | ... |
484 | other_func() |
485 | { |
486 | strcpy(buffer, lotsa_chars); /* happily uses global *buffer */ |
487 | ... |
488 | foo_main() |
489 | { |
490 | buffer = xmalloc(sizeof(char)*BUFSIZ); |
491 | ... |
492 | |
493 | However, this approach trades bss segment for text segment. Rather than |
494 | mallocing the buffers (and thus growing the text size), buffers can be |
495 | declared on the stack in the *_main() function and made available globally by |
496 | assigning them to a global pointer thusly: |
497 | |
498 | static char *pbuffer; |
499 | ... |
500 | other_func() |
501 | { |
502 | strcpy(pbuffer, lotsa_chars); /* happily uses global *pbuffer */ |
503 | ... |
504 | foo_main() |
505 | { |
506 | char *buffer[BUFSIZ]; /* declared locally, on stack */ |
507 | pbuffer = buffer; /* but available globally */ |
508 | ... |
509 | |
510 | This last approach has some advantages (low code size, space not used until |
511 | it's needed), but can be a problem in some low resource machines that have |
512 | very limited stack space (e.g., uCLinux). |
513 | |
514 | A macro is declared in busybox.h that implements compile-time selection |
515 | between xmalloc() and stack creation, so you can code the line in question as |
516 | |
517 | RESERVE_CONFIG_BUFFER(buffer, BUFSIZ); |
518 | |
519 | and the right thing will happen, based on your configuration. |
520 | |
521 | Another relatively new trick of similar nature is explained |
522 | in keep_data_small.txt. |
523 | |
524 | |
525 | |
526 | Miscellaneous Coding Guidelines |
527 | ------------------------------- |
528 | |
529 | The following are important items that don't fit into any of the above |
530 | sections. |
531 | |
532 | |
533 | Model Busybox Applets After GNU Counterparts |
534 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
535 | |
536 | When in doubt about the proper behavior of a Busybox program (output, |
537 | formatting, options, etc.), model it after the equivalent GNU program. |
538 | Doesn't matter how that program behaves on some other flavor of *NIX; doesn't |
539 | matter what the POSIX standard says or doesn't say, just model Busybox |
540 | programs after their GNU counterparts and it will make life easier on (nearly) |
541 | everyone. |
542 | |
543 | The only time we deviate from emulating the GNU behavior is when: |
544 | |
545 | - We are deliberately not supporting a feature (such as a command line |
546 | switch) |
547 | - Emulating the GNU behavior is prohibitively expensive (lots more code |
548 | would be required, lots more memory would be used, etc.) |
549 | - The difference is minor or cosmetic |
550 | |
551 | A note on the 'cosmetic' case: output differences might be considered |
552 | cosmetic, but if the output is significant enough to break other scripts that |
553 | use the output, it should really be fixed. |
554 | |
555 | |
556 | Scope |
557 | ~~~~~ |
558 | |
559 | If a const variable is used only in a single source file, put it in the source |
560 | file and not in a header file. Likewise, if a const variable is used in only |
561 | one function, do not make it global to the file. Instead, declare it inside |
562 | the function body. Bottom line: Make a conscious effort to limit declarations |
563 | to the smallest scope possible. |
564 | |
565 | Inside applet files, all functions should be declared static so as to keep the |
566 | global name space clean. The only exception to this rule is the "applet_main" |
567 | function which must be declared extern. |
568 | |
569 | If you write a function that performs a task that could be useful outside the |
570 | immediate file, turn it into a general-purpose function with no ties to any |
571 | applet and put it in the utility.c file instead. |
572 | |
573 | |
574 | Brackets Are Your Friends |
575 | ~~~~~~~~~~~~~~~~~~~~~~~~~ |
576 | |
577 | Please use brackets on all if and else statements, even if it is only one |
578 | line. Example: |
579 | |
580 | Don't do this: |
581 | |
582 | if (foo) |
583 | stmt1; |
584 | stmt2 |
585 | stmt3; |
586 | |
587 | Do this instead: |
588 | |
589 | if (foo) { |
590 | stmt1; |
591 | } |
592 | stmt2 |
593 | stmt3; |
594 | |
595 | The "bracketless" approach is error prone because someday you might add a line |
596 | like this: |
597 | |
598 | if (foo) |
599 | stmt1; |
600 | new_line(); |
601 | stmt2; |
602 | stmt3; |
603 | |
604 | And the resulting behavior of your program would totally bewilder you. (Don't |
605 | laugh, it happens to us all.) Remember folks, this is C, not Python. |
606 | |
607 | |
608 | Function Declarations |
609 | ~~~~~~~~~~~~~~~~~~~~~ |
610 | |
611 | Do not use old-style function declarations that declare variable types between |
612 | the parameter list and opening bracket. Example: |
613 | |
614 | Don't do this: |
615 | |
616 | int foo(parm1, parm2) |
617 | char parm1; |
618 | float parm2; |
619 | { |
620 | .... |
621 | |
622 | Do this instead: |
623 | |
624 | int foo(char parm1, float parm2) |
625 | { |
626 | .... |
627 | |
628 | The only time you would ever need to use the old declaration syntax is to |
629 | support ancient, antediluvian compilers. To our good fortune, we have access |
630 | to more modern compilers and the old declaration syntax is neither necessary |
631 | nor desired. |
632 | |
633 | |
634 | Emphasizing Logical Blocks |
635 | ~~~~~~~~~~~~~~~~~~~~~~~~~~ |
636 | |
637 | Organization and readability are improved by putting extra newlines around |
638 | blocks of code that perform a single task. These are typically blocks that |
639 | begin with a C keyword, but not always. |
640 | |
641 | Furthermore, you should put a single comment (not necessarily one line, just |
642 | one comment) before the block, rather than commenting each and every line. |
643 | There is an optimal amount of commenting that a program can have; you can |
644 | comment too much as well as too little. |
645 | |
646 | A picture is really worth a thousand words here, the following example |
647 | illustrates how to emphasize logical blocks: |
648 | |
649 | while (line = xmalloc_fgets(fp)) { |
650 | |
651 | /* eat the newline, if any */ |
652 | chomp(line); |
653 | |
654 | /* ignore blank lines */ |
655 | if (strlen(file_to_act_on) == 0) { |
656 | continue; |
657 | } |
658 | |
659 | /* if the search string is in this line, print it, |
660 | * unless we were told to be quiet */ |
661 | if (strstr(line, search) && !be_quiet) { |
662 | puts(line); |
663 | } |
664 | |
665 | /* clean up */ |
666 | free(line); |
667 | } |
668 | |
669 | |
670 | Processing Options with getopt |
671 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
672 | |
673 | If your applet needs to process command-line switches, please use getopt32() to |
674 | do so. Numerous examples can be seen in many of the existing applets, but |
675 | basically it boils down to two things: at the top of the .c file, have this |
676 | line in the midst of your #includes, if you need to parse long options: |
677 | |
678 | #include <getopt.h> |
679 | |
680 | Then have long options defined: |
681 | |
682 | static const struct option <applet>_long_options[] = { |
683 | { "list", 0, NULL, 't' }, |
684 | { "extract", 0, NULL, 'x' }, |
685 | { NULL, 0, NULL, 0 } |
686 | }; |
687 | |
688 | And a code block similar to the following near the top of your applet_main() |
689 | routine: |
690 | |
691 | char *str_b; |
692 | |
693 | opt_complementary = "cryptic_string"; |
694 | applet_long_options = <applet>_long_options; /* if you have them */ |
695 | opt = getopt32(argc, argv, "ab:c", &str_b); |
696 | if (opt & 1) { |
697 | handle_option_a(); |
698 | } |
699 | if (opt & 2) { |
700 | handle_option_b(str_b); |
701 | } |
702 | if (opt & 4) { |
703 | handle_option_c(); |
704 | } |
705 | |
706 | If your applet takes no options (such as 'init'), there should be a line |
707 | somewhere in the file reads: |
708 | |
709 | /* no options, no getopt */ |
710 | |
711 | That way, when people go grepping to see which applets need to be converted to |
712 | use getopt, they won't get false positives. |
713 | |
714 | For more info and examples, examine getopt32.c, tar.c, wget.c etc. |