1 /* quotearg.h - quote arguments for output
2 
3    Copyright (C) 1998-2002, 2004, 2006, 2008-2021 Free Software Foundation,
4    Inc.
5 
6    This program is free software: you can redistribute it and/or modify
7    it under the terms of the GNU General Public License as published by
8    the Free Software Foundation; either version 3 of the License, or
9    (at your option) any later version.
10 
11    This program is distributed in the hope that it will be useful,
12    but WITHOUT ANY WARRANTY; without even the implied warranty of
13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14    GNU General Public License for more details.
15 
16    You should have received a copy of the GNU General Public License
17    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
18 
19 /* Written by Paul Eggert <eggert@twinsun.com> */
20 
21 #ifndef QUOTEARG_H_
22 # define QUOTEARG_H_ 1
23 
24 # include <stddef.h>
25 # include <stdlib.h>
26 
27 /* Basic quoting styles.  For each style, an example is given on the
28    input strings "simple", "\0 \t\n'\"\033?""?/\\", and "a:b", using
29    quotearg_buffer, quotearg_mem, and quotearg_colon_mem with that
30    style and the default flags and quoted characters.  Note that the
31    examples are shown here as valid C strings rather than what
32    displays on a terminal (with "??/" as a trigraph for "\\").  */
33 enum quoting_style
34   {
35     /* Output names as-is (ls --quoting-style=literal).  Can result in
36        embedded null bytes if QA_ELIDE_NULL_BYTES is not in
37        effect.
38 
39        quotearg_buffer:
40        "simple", "\0 \t\n'\"\033??/\\", "a:b"
41        quotearg:
42        "simple", " \t\n'\"\033??/\\", "a:b"
43        quotearg_colon:
44        "simple", " \t\n'\"\033??/\\", "a:b"
45     */
46     literal_quoting_style,
47 
48     /* Quote names for the shell if they contain shell metacharacters
49        or would cause ambiguous output (ls --quoting-style=shell).
50        Can result in embedded null bytes if QA_ELIDE_NULL_BYTES is not
51        in effect.
52 
53        quotearg_buffer:
54        "simple", "'\0 \t\n'\\''\"\033??/\\'", "a:b"
55        quotearg:
56        "simple", "' \t\n'\\''\"\033??/\\'", "a:b"
57        quotearg_colon:
58        "simple", "' \t\n'\\''\"\033??/\\'", "'a:b'"
59     */
60     shell_quoting_style,
61 
62     /* Quote names for the shell, even if they would normally not
63        require quoting (ls --quoting-style=shell-always).  Can result
64        in embedded null bytes if QA_ELIDE_NULL_BYTES is not in effect.
65        Behaves like shell_quoting_style if QA_ELIDE_OUTER_QUOTES is in
66        effect.
67 
68        quotearg_buffer:
69        "'simple'", "'\0 \t\n'\\''\"\033??/\\'", "'a:b'"
70        quotearg:
71        "'simple'", "' \t\n'\\''\"\033??/\\'", "'a:b'"
72        quotearg_colon:
73        "'simple'", "' \t\n'\\''\"\033??/\\'", "'a:b'"
74     */
75     shell_always_quoting_style,
76 
77     /* Quote names for the shell if they contain shell metacharacters
78        or other problematic characters (ls --quoting-style=shell-escape).
79        Non printable characters are quoted using the $'...' syntax,
80        which originated in ksh93 and is widely supported by most shells,
81        and proposed for inclusion in POSIX.
82 
83        quotearg_buffer:
84        "simple", "''$'\\0'' '$'\\t\\n'\\''\"'$'\\033''??/\\'", "a:b"
85        quotearg:
86        "simple", "''$'\\0'' '$'\\t\\n'\\''\"'$'\\033''??/\\'", "a:b"
87        quotearg_colon:
88        "simple", "''$'\\0'' '$'\\t\\n'\\''\"'$'\\033''??/\\'", "'a:b'"
89     */
90     shell_escape_quoting_style,
91 
92     /* Quote names for the shell even if they would normally not
93        require quoting (ls --quoting-style=shell-escape).
94        Non printable characters are quoted using the $'...' syntax,
95        which originated in ksh93 and is widely supported by most shells,
96        and proposed for inclusion in POSIX.  Behaves like
97        shell_escape_quoting_style if QA_ELIDE_OUTER_QUOTES is in effect.
98 
99        quotearg_buffer:
100        "simple", "''$'\\0'' '$'\\t\\n'\\''\"'$'\\033''??/\'", "a:b"
101        quotearg:
102        "simple", "''$'\\0'' '$'\\t\\n'\\''\"'$'\\033''??/\'", "a:b"
103        quotearg_colon:
104        "simple", "''$'\\0'' '$'\\t\\n'\\''\"'$'\\033''??/\'", "'a:b'"
105     */
106     shell_escape_always_quoting_style,
107 
108     /* Quote names as for a C language string (ls --quoting-style=c).
109        Behaves like c_maybe_quoting_style if QA_ELIDE_OUTER_QUOTES is
110        in effect.  Split into consecutive strings if
111        QA_SPLIT_TRIGRAPHS.
112 
113        quotearg_buffer:
114        "\"simple\"", "\"\\0 \\t\\n'\\\"\\033??/\\\\\"", "\"a:b\""
115        quotearg:
116        "\"simple\"", "\"\\0 \\t\\n'\\\"\\033??/\\\\\"", "\"a:b\""
117        quotearg_colon:
118        "\"simple\"", "\"\\0 \\t\\n'\\\"\\033??/\\\\\"", "\"a\\:b\""
119     */
120     c_quoting_style,
121 
122     /* Like c_quoting_style except omit the surrounding double-quote
123        characters if no quoted characters are encountered.
124 
125        quotearg_buffer:
126        "simple", "\"\\0 \\t\\n'\\\"\\033??/\\\\\"", "a:b"
127        quotearg:
128        "simple", "\"\\0 \\t\\n'\\\"\\033??/\\\\\"", "a:b"
129        quotearg_colon:
130        "simple", "\"\\0 \\t\\n'\\\"\\033??/\\\\\"", "\"a:b\""
131     */
132     c_maybe_quoting_style,
133 
134     /* Like c_quoting_style except always omit the surrounding
135        double-quote characters and ignore QA_SPLIT_TRIGRAPHS
136        (ls --quoting-style=escape).
137 
138        quotearg_buffer:
139        "simple", "\\0 \\t\\n'\"\\033??/\\\\", "a:b"
140        quotearg:
141        "simple", "\\0 \\t\\n'\"\\033??/\\\\", "a:b"
142        quotearg_colon:
143        "simple", "\\0 \\t\\n'\"\\033??/\\\\", "a\\:b"
144     */
145     escape_quoting_style,
146 
147     /* Like clocale_quoting_style, but use single quotes in the
148        default C locale or if the program does not use gettext
149        (ls --quoting-style=locale).  For UTF-8 locales, quote
150        characters will use Unicode.
151 
152        LC_MESSAGES=C
153        quotearg_buffer:
154        "`simple'", "`\\0 \\t\\n\\'\"\\033??/\\\\'", "`a:b'"
155        quotearg:
156        "`simple'", "`\\0 \\t\\n\\'\"\\033??/\\\\'", "`a:b'"
157        quotearg_colon:
158        "`simple'", "`\\0 \\t\\n\\'\"\\033??/\\\\'", "`a\\:b'"
159 
160        LC_MESSAGES=pt_PT.utf8
161        quotearg_buffer:
162        "\302\253simple\302\273",
163        "\302\253\\0 \\t\\n'\"\\033??/\\\\\302\253", "\302\253a:b\302\273"
164        quotearg:
165        "\302\253simple\302\273",
166        "\302\253\\0 \\t\\n'\"\\033??/\\\\\302\253", "\302\253a:b\302\273"
167        quotearg_colon:
168        "\302\253simple\302\273",
169        "\302\253\\0 \\t\\n'\"\\033??/\\\\\302\253", "\302\253a\\:b\302\273"
170     */
171     locale_quoting_style,
172 
173     /* Like c_quoting_style except use quotation marks appropriate for
174        the locale and ignore QA_SPLIT_TRIGRAPHS
175        (ls --quoting-style=clocale).
176 
177        LC_MESSAGES=C
178        quotearg_buffer:
179        "\"simple\"", "\"\\0 \\t\\n'\\\"\\033??/\\\\\"", "\"a:b\""
180        quotearg:
181        "\"simple\"", "\"\\0 \\t\\n'\\\"\\033??/\\\\\"", "\"a:b\""
182        quotearg_colon:
183        "\"simple\"", "\"\\0 \\t\\n'\\\"\\033??/\\\\\"", "\"a\\:b\""
184 
185        LC_MESSAGES=pt_PT.utf8
186        quotearg_buffer:
187        "\302\253simple\302\273",
188        "\302\253\\0 \\t\\n'\"\\033??/\\\\\302\253", "\302\253a:b\302\273"
189        quotearg:
190        "\302\253simple\302\273",
191        "\302\253\\0 \\t\\n'\"\\033??/\\\\\302\253", "\302\253a:b\302\273"
192        quotearg_colon:
193        "\302\253simple\302\273",
194        "\302\253\\0 \\t\\n'\"\\033??/\\\\\302\253", "\302\253a\\:b\302\273"
195     */
196     clocale_quoting_style,
197 
198     /* Like clocale_quoting_style except use the custom quotation marks
199        set by set_custom_quoting.  If custom quotation marks are not
200        set, the behavior is undefined.
201 
202        left_quote = right_quote = "'"
203        quotearg_buffer:
204        "'simple'", "'\\0 \\t\\n\\'\"\\033??/\\\\'", "'a:b'"
205        quotearg:
206        "'simple'", "'\\0 \\t\\n\\'\"\\033??/\\\\'", "'a:b'"
207        quotearg_colon:
208        "'simple'", "'\\0 \\t\\n\\'\"\\033??/\\\\'", "'a\\:b'"
209 
210        left_quote = "(" and right_quote = ")"
211        quotearg_buffer:
212        "(simple)", "(\\0 \\t\\n'\"\\033??/\\\\)", "(a:b)"
213        quotearg:
214        "(simple)", "(\\0 \\t\\n'\"\\033??/\\\\)", "(a:b)"
215        quotearg_colon:
216        "(simple)", "(\\0 \\t\\n'\"\\033??/\\\\)", "(a\\:b)"
217 
218        left_quote = ":" and right_quote = " "
219        quotearg_buffer:
220        ":simple ", ":\\0\\ \\t\\n'\"\\033??/\\\\ ", ":a:b "
221        quotearg:
222        ":simple ", ":\\0\\ \\t\\n'\"\\033??/\\\\ ", ":a:b "
223        quotearg_colon:
224        ":simple ", ":\\0\\ \\t\\n'\"\\033??/\\\\ ", ":a\\:b "
225 
226        left_quote = "\"'" and right_quote = "'\""
227        Notice that this is treated as a single level of quotes or two
228        levels where the outer quote need not be escaped within the inner
229        quotes.  For two levels where the outer quote must be escaped
230        within the inner quotes, you must use separate quotearg
231        invocations.
232        quotearg_buffer:
233        "\"'simple'\"", "\"'\\0 \\t\\n\\'\"\\033??/\\\\'\"", "\"'a:b'\""
234        quotearg:
235        "\"'simple'\"", "\"'\\0 \\t\\n\\'\"\\033??/\\\\'\"", "\"'a:b'\""
236        quotearg_colon:
237        "\"'simple'\"", "\"'\\0 \\t\\n\\'\"\\033??/\\\\'\"", "\"'a\\:b'\""
238     */
239     custom_quoting_style
240   };
241 
242 /* Flags for use in set_quoting_flags.  */
243 enum quoting_flags
244   {
245     /* Always elide null bytes from styles that do not quote them,
246        even when the length of the result is available to the
247        caller.  */
248     QA_ELIDE_NULL_BYTES = 0x01,
249 
250     /* Omit the surrounding quote characters if no escaped characters
251        are encountered.  Note that if no other character needs
252        escaping, then neither does the escape character.  */
253     QA_ELIDE_OUTER_QUOTES = 0x02,
254 
255     /* In the c_quoting_style and c_maybe_quoting_style, split ANSI
256        trigraph sequences into concatenated strings (for example,
257        "?""?/" rather than "??/", which could be confused with
258        "\\").  */
259     QA_SPLIT_TRIGRAPHS = 0x04
260   };
261 
262 /* For now, --quoting-style=literal is the default, but this may change.  */
263 # ifndef DEFAULT_QUOTING_STYLE
264 #  define DEFAULT_QUOTING_STYLE literal_quoting_style
265 # endif
266 
267 /* Names of quoting styles and their corresponding values.  */
268 extern char const *const quoting_style_args[];
269 extern enum quoting_style const quoting_style_vals[];
270 
271 struct quoting_options;
272 
273 /* The functions listed below set and use a hidden variable
274    that contains the default quoting style options.  */
275 
276 /* Allocate a new set of quoting options, with contents initially identical
277    to O if O is not null, or to the default if O is null.
278    It is the caller's responsibility to free the result.  */
279 struct quoting_options *clone_quoting_options (struct quoting_options *o)
280   _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_DEALLOC_FREE
281   _GL_ATTRIBUTE_RETURNS_NONNULL;
282 /* Get the value of O's quoting style.  If O is null, use the default.  */
283 enum quoting_style get_quoting_style (struct quoting_options const *o);
284 
285 /* In O (or in the default if O is null),
286    set the value of the quoting style to S.  */
287 void set_quoting_style (struct quoting_options *o, enum quoting_style s);
288 
289 /* In O (or in the default if O is null),
290    set the value of the quoting options for character C to I.
291    Return the old value.  Currently, the only values defined for I are
292    0 (the default) and 1 (which means to quote the character even if
293    it would not otherwise be quoted).  C must never be a digit or a
294    letter that has special meaning after a backslash (for example, "\t"
295    for tab).  */
296 int set_char_quoting (struct quoting_options *o, char c, int i);
297 
298 /* In O (or in the default if O is null),
299    set the value of the quoting options flag to I, which can be a
300    bitwise combination of enum quoting_flags, or 0 for default
301    behavior.  Return the old value.  */
302 int set_quoting_flags (struct quoting_options *o, int i);
303 
304 /* In O (or in the default if O is null),
305    set the value of the quoting style to custom_quoting_style,
306    set the left quote to LEFT_QUOTE, and set the right quote to
307    RIGHT_QUOTE.  Each of LEFT_QUOTE and RIGHT_QUOTE must be
308    null-terminated and can be the empty string.  Because backslashes are
309    used for escaping, it does not make sense for RIGHT_QUOTE to contain
310    a backslash.  RIGHT_QUOTE must not begin with a digit or a letter
311    that has special meaning after a backslash (for example, "\t" for
312    tab).  */
313 void set_custom_quoting (struct quoting_options *o,
314                          char const *left_quote,
315                          char const *right_quote);
316 
317 /* Place into buffer BUFFER (of size BUFFERSIZE) a quoted version of
318    argument ARG (of size ARGSIZE), using O to control quoting.
319    If O is null, use the default.
320    Terminate the output with a null character, and return the written
321    size of the output, not counting the terminating null.
322    If BUFFERSIZE is too small to store the output string, return the
323    value that would have been returned had BUFFERSIZE been large enough.
324    If ARGSIZE is -1, use the string length of the argument for ARGSIZE.
325    On output, BUFFER might contain embedded null bytes if ARGSIZE was
326    not -1, the style of O does not use backslash escapes, and the
327    flags of O do not request elision of null bytes.*/
328 size_t quotearg_buffer (char *restrict buffer, size_t buffersize,
329                         char const *arg, size_t argsize,
330                         struct quoting_options const *o);
331 
332 /* Like quotearg_buffer, except return the result in a newly allocated
333    buffer.  It is the caller's responsibility to free the result.  The
334    result will not contain embedded null bytes.  */
335 char *quotearg_alloc (char const *arg, size_t argsize,
336                       struct quoting_options const *o);
337 
338 /* Like quotearg_alloc, except that the length of the result,
339    excluding the terminating null byte, is stored into SIZE if it is
340    non-NULL.  The result might contain embedded null bytes if ARGSIZE
341    was not -1, SIZE was not NULL, the style of O does not use
342    backslash escapes, and the flags of O do not request elision of
343    null bytes.*/
344 char *quotearg_alloc_mem (char const *arg, size_t argsize,
345                           size_t *size, struct quoting_options const *o);
346 
347 /* Use storage slot N to return a quoted version of the string ARG.
348    Use the default quoting options.
349    The returned value points to static storage that can be
350    reused by the next call to this function with the same value of N.
351    N must be nonnegative.  The output of all functions in the
352    quotearg_n family are guaranteed to not contain embedded null
353    bytes.*/
354 char *quotearg_n (int n, char const *arg);
355 
356 /* Equivalent to quotearg_n (0, ARG).  */
357 char *quotearg (char const *arg);
358 
359 /* Use storage slot N to return a quoted version of the argument ARG
360    of size ARGSIZE.  This is like quotearg_n (N, ARG), except it can
361    quote null bytes.  */
362 char *quotearg_n_mem (int n, char const *arg, size_t argsize);
363 
364 /* Equivalent to quotearg_n_mem (0, ARG, ARGSIZE).  */
365 char *quotearg_mem (char const *arg, size_t argsize);
366 
367 /* Use style S and storage slot N to return a quoted version of the string ARG.
368    This is like quotearg_n (N, ARG), except that it uses S with no other
369    options to specify the quoting method.  */
370 char *quotearg_n_style (int n, enum quoting_style s, char const *arg);
371 
372 /* Use style S and storage slot N to return a quoted version of the
373    argument ARG of size ARGSIZE.  This is like quotearg_n_style
374    (N, S, ARG), except it can quote null bytes.  */
375 char *quotearg_n_style_mem (int n, enum quoting_style s,
376                             char const *arg, size_t argsize);
377 
378 /* Equivalent to quotearg_n_style (0, S, ARG).  */
379 char *quotearg_style (enum quoting_style s, char const *arg);
380 
381 /* Equivalent to quotearg_n_style_mem (0, S, ARG, ARGSIZE).  */
382 char *quotearg_style_mem (enum quoting_style s,
383                           char const *arg, size_t argsize);
384 
385 /* Like quotearg (ARG), except also quote any instances of CH.
386    See set_char_quoting for a description of acceptable CH values.  */
387 char *quotearg_char (char const *arg, char ch);
388 
389 /* Like quotearg_char (ARG, CH), except it can quote null bytes.  */
390 char *quotearg_char_mem (char const *arg, size_t argsize, char ch);
391 
392 /* Equivalent to quotearg_char (ARG, ':').  */
393 char *quotearg_colon (char const *arg);
394 
395 /* Like quotearg_colon (ARG), except it can quote null bytes.  */
396 char *quotearg_colon_mem (char const *arg, size_t argsize);
397 
398 /* Like quotearg_n_style, except with ':' quoting enabled.  */
399 char *quotearg_n_style_colon (int n, enum quoting_style s, char const *arg);
400 
401 /* Like quotearg_n_style (N, S, ARG) but with S as custom_quoting_style
402    with left quote as LEFT_QUOTE and right quote as RIGHT_QUOTE.  See
403    set_custom_quoting for a description of acceptable LEFT_QUOTE and
404    RIGHT_QUOTE values.  */
405 char *quotearg_n_custom (int n, char const *left_quote,
406                          char const *right_quote, char const *arg);
407 
408 /* Like quotearg_n_custom (N, LEFT_QUOTE, RIGHT_QUOTE, ARG) except it
409    can quote null bytes.  */
410 char *quotearg_n_custom_mem (int n, char const *left_quote,
411                              char const *right_quote,
412                              char const *arg, size_t argsize);
413 
414 /* Equivalent to quotearg_n_custom (0, LEFT_QUOTE, RIGHT_QUOTE, ARG).  */
415 char *quotearg_custom (char const *left_quote, char const *right_quote,
416                        char const *arg);
417 
418 /* Equivalent to quotearg_n_custom_mem (0, LEFT_QUOTE, RIGHT_QUOTE, ARG,
419                                         ARGSIZE).  */
420 char *quotearg_custom_mem (char const *left_quote,
421                            char const *right_quote,
422                            char const *arg, size_t argsize);
423 
424 /* Free any dynamically allocated memory.  */
425 void quotearg_free (void);
426 
427 #endif /* !QUOTEARG_H_ */
428