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 <stdlib.h>
25 
26 /* Basic quoting styles.  For each style, an example is given on the
27    input strings "simple", "\0 \t\n'\"\033?""?/\\", and "a:b", using
28    quotearg_buffer, quotearg_mem, and quotearg_colon_mem with that
29    style and the default flags and quoted characters.  Note that the
30    examples are shown here as valid C strings rather than what
31    displays on a terminal (with "??/" as a trigraph for "\\").  */
32 enum quoting_style
33   {
34     /* Output names as-is (ls --quoting-style=literal).  Can result in
35        embedded null bytes if QA_ELIDE_NULL_BYTES is not in
36        effect.
37 
38        quotearg_buffer:
39        "simple", "\0 \t\n'\"\033??/\\", "a:b"
40        quotearg:
41        "simple", " \t\n'\"\033??/\\", "a:b"
42        quotearg_colon:
43        "simple", " \t\n'\"\033??/\\", "a:b"
44     */
45     literal_quoting_style,
46 
47     /* Quote names for the shell if they contain shell metacharacters
48        or would cause ambiguous output (ls --quoting-style=shell).
49        Can result in embedded null bytes if QA_ELIDE_NULL_BYTES is not
50        in effect.
51 
52        quotearg_buffer:
53        "simple", "'\0 \t\n'\\''\"\033??/\\'", "a:b"
54        quotearg:
55        "simple", "' \t\n'\\''\"\033??/\\'", "a:b"
56        quotearg_colon:
57        "simple", "' \t\n'\\''\"\033??/\\'", "'a:b'"
58     */
59     shell_quoting_style,
60 
61     /* Quote names for the shell, even if they would normally not
62        require quoting (ls --quoting-style=shell-always).  Can result
63        in embedded null bytes if QA_ELIDE_NULL_BYTES is not in effect.
64        Behaves like shell_quoting_style if QA_ELIDE_OUTER_QUOTES is in
65        effect.
66 
67        quotearg_buffer:
68        "'simple'", "'\0 \t\n'\\''\"\033??/\\'", "'a:b'"
69        quotearg:
70        "'simple'", "' \t\n'\\''\"\033??/\\'", "'a:b'"
71        quotearg_colon:
72        "'simple'", "' \t\n'\\''\"\033??/\\'", "'a:b'"
73     */
74     shell_always_quoting_style,
75 
76     /* Quote names for the shell if they contain shell metacharacters
77        or other problematic characters (ls --quoting-style=shell-escape).
78        Non printable characters are quoted using the $'...' syntax,
79        which originated in ksh93 and is widely supported by most shells,
80        and proposed for inclusion in POSIX.
81 
82        quotearg_buffer:
83        "simple", "''$'\\0'' '$'\\t\\n'\\''\"'$'\\033''??/\\'", "a:b"
84        quotearg:
85        "simple", "''$'\\0'' '$'\\t\\n'\\''\"'$'\\033''??/\\'", "a:b"
86        quotearg_colon:
87        "simple", "''$'\\0'' '$'\\t\\n'\\''\"'$'\\033''??/\\'", "'a:b'"
88     */
89     shell_escape_quoting_style,
90 
91     /* Quote names for the shell even if they would normally not
92        require quoting (ls --quoting-style=shell-escape).
93        Non printable characters are quoted using the $'...' syntax,
94        which originated in ksh93 and is widely supported by most shells,
95        and proposed for inclusion in POSIX.  Behaves like
96        shell_escape_quoting_style if QA_ELIDE_OUTER_QUOTES is in effect.
97 
98        quotearg_buffer:
99        "simple", "''$'\\0'' '$'\\t\\n'\\''\"'$'\\033''??/\'", "a:b"
100        quotearg:
101        "simple", "''$'\\0'' '$'\\t\\n'\\''\"'$'\\033''??/\'", "a:b"
102        quotearg_colon:
103        "simple", "''$'\\0'' '$'\\t\\n'\\''\"'$'\\033''??/\'", "'a:b'"
104     */
105     shell_escape_always_quoting_style,
106 
107     /* Quote names as for a C language string (ls --quoting-style=c).
108        Behaves like c_maybe_quoting_style if QA_ELIDE_OUTER_QUOTES is
109        in effect.  Split into consecutive strings if
110        QA_SPLIT_TRIGRAPHS.
111 
112        quotearg_buffer:
113        "\"simple\"", "\"\\0 \\t\\n'\\\"\\033??/\\\\\"", "\"a:b\""
114        quotearg:
115        "\"simple\"", "\"\\0 \\t\\n'\\\"\\033??/\\\\\"", "\"a:b\""
116        quotearg_colon:
117        "\"simple\"", "\"\\0 \\t\\n'\\\"\\033??/\\\\\"", "\"a\\:b\""
118     */
119     c_quoting_style,
120 
121     /* Like c_quoting_style except omit the surrounding double-quote
122        characters if no quoted characters are encountered.
123 
124        quotearg_buffer:
125        "simple", "\"\\0 \\t\\n'\\\"\\033??/\\\\\"", "a:b"
126        quotearg:
127        "simple", "\"\\0 \\t\\n'\\\"\\033??/\\\\\"", "a:b"
128        quotearg_colon:
129        "simple", "\"\\0 \\t\\n'\\\"\\033??/\\\\\"", "\"a:b\""
130     */
131     c_maybe_quoting_style,
132 
133     /* Like c_quoting_style except always omit the surrounding
134        double-quote characters and ignore QA_SPLIT_TRIGRAPHS
135        (ls --quoting-style=escape).
136 
137        quotearg_buffer:
138        "simple", "\\0 \\t\\n'\"\\033??/\\\\", "a:b"
139        quotearg:
140        "simple", "\\0 \\t\\n'\"\\033??/\\\\", "a:b"
141        quotearg_colon:
142        "simple", "\\0 \\t\\n'\"\\033??/\\\\", "a\\:b"
143     */
144     escape_quoting_style,
145 
146     /* Like clocale_quoting_style, but use single quotes in the
147        default C locale or if the program does not use gettext
148        (ls --quoting-style=locale).  For UTF-8 locales, quote
149        characters will use Unicode.
150 
151        LC_MESSAGES=C
152        quotearg_buffer:
153        "`simple'", "`\\0 \\t\\n\\'\"\\033??/\\\\'", "`a:b'"
154        quotearg:
155        "`simple'", "`\\0 \\t\\n\\'\"\\033??/\\\\'", "`a:b'"
156        quotearg_colon:
157        "`simple'", "`\\0 \\t\\n\\'\"\\033??/\\\\'", "`a\\:b'"
158 
159        LC_MESSAGES=pt_PT.utf8
160        quotearg_buffer:
161        "\302\253simple\302\273",
162        "\302\253\\0 \\t\\n'\"\\033??/\\\\\302\253", "\302\253a:b\302\273"
163        quotearg:
164        "\302\253simple\302\273",
165        "\302\253\\0 \\t\\n'\"\\033??/\\\\\302\253", "\302\253a:b\302\273"
166        quotearg_colon:
167        "\302\253simple\302\273",
168        "\302\253\\0 \\t\\n'\"\\033??/\\\\\302\253", "\302\253a\\:b\302\273"
169     */
170     locale_quoting_style,
171 
172     /* Like c_quoting_style except use quotation marks appropriate for
173        the locale and ignore QA_SPLIT_TRIGRAPHS
174        (ls --quoting-style=clocale).
175 
176        LC_MESSAGES=C
177        quotearg_buffer:
178        "\"simple\"", "\"\\0 \\t\\n'\\\"\\033??/\\\\\"", "\"a:b\""
179        quotearg:
180        "\"simple\"", "\"\\0 \\t\\n'\\\"\\033??/\\\\\"", "\"a:b\""
181        quotearg_colon:
182        "\"simple\"", "\"\\0 \\t\\n'\\\"\\033??/\\\\\"", "\"a\\:b\""
183 
184        LC_MESSAGES=pt_PT.utf8
185        quotearg_buffer:
186        "\302\253simple\302\273",
187        "\302\253\\0 \\t\\n'\"\\033??/\\\\\302\253", "\302\253a:b\302\273"
188        quotearg:
189        "\302\253simple\302\273",
190        "\302\253\\0 \\t\\n'\"\\033??/\\\\\302\253", "\302\253a:b\302\273"
191        quotearg_colon:
192        "\302\253simple\302\273",
193        "\302\253\\0 \\t\\n'\"\\033??/\\\\\302\253", "\302\253a\\:b\302\273"
194     */
195     clocale_quoting_style,
196 
197     /* Like clocale_quoting_style except use the custom quotation marks
198        set by set_custom_quoting.  If custom quotation marks are not
199        set, the behavior is undefined.
200 
201        left_quote = right_quote = "'"
202        quotearg_buffer:
203        "'simple'", "'\\0 \\t\\n\\'\"\\033??/\\\\'", "'a:b'"
204        quotearg:
205        "'simple'", "'\\0 \\t\\n\\'\"\\033??/\\\\'", "'a:b'"
206        quotearg_colon:
207        "'simple'", "'\\0 \\t\\n\\'\"\\033??/\\\\'", "'a\\:b'"
208 
209        left_quote = "(" and right_quote = ")"
210        quotearg_buffer:
211        "(simple)", "(\\0 \\t\\n'\"\\033??/\\\\)", "(a:b)"
212        quotearg:
213        "(simple)", "(\\0 \\t\\n'\"\\033??/\\\\)", "(a:b)"
214        quotearg_colon:
215        "(simple)", "(\\0 \\t\\n'\"\\033??/\\\\)", "(a\\:b)"
216 
217        left_quote = ":" and right_quote = " "
218        quotearg_buffer:
219        ":simple ", ":\\0\\ \\t\\n'\"\\033??/\\\\ ", ":a:b "
220        quotearg:
221        ":simple ", ":\\0\\ \\t\\n'\"\\033??/\\\\ ", ":a:b "
222        quotearg_colon:
223        ":simple ", ":\\0\\ \\t\\n'\"\\033??/\\\\ ", ":a\\:b "
224 
225        left_quote = "\"'" and right_quote = "'\""
226        Notice that this is treated as a single level of quotes or two
227        levels where the outer quote need not be escaped within the inner
228        quotes.  For two levels where the outer quote must be escaped
229        within the inner quotes, you must use separate quotearg
230        invocations.
231        quotearg_buffer:
232        "\"'simple'\"", "\"'\\0 \\t\\n\\'\"\\033??/\\\\'\"", "\"'a:b'\""
233        quotearg:
234        "\"'simple'\"", "\"'\\0 \\t\\n\\'\"\\033??/\\\\'\"", "\"'a:b'\""
235        quotearg_colon:
236        "\"'simple'\"", "\"'\\0 \\t\\n\\'\"\\033??/\\\\'\"", "\"'a\\:b'\""
237     */
238     custom_quoting_style
239   };
240 
241 /* Flags for use in set_quoting_flags.  */
242 enum quoting_flags
243   {
244     /* Always elide null bytes from styles that do not quote them,
245        even when the length of the result is available to the
246        caller.  */
247     QA_ELIDE_NULL_BYTES = 0x01,
248 
249     /* Omit the surrounding quote characters if no escaped characters
250        are encountered.  Note that if no other character needs
251        escaping, then neither does the escape character.  */
252     QA_ELIDE_OUTER_QUOTES = 0x02,
253 
254     /* In the c_quoting_style and c_maybe_quoting_style, split ANSI
255        trigraph sequences into concatenated strings (for example,
256        "?""?/" rather than "??/", which could be confused with
257        "\\").  */
258     QA_SPLIT_TRIGRAPHS = 0x04
259   };
260 
261 /* For now, --quoting-style=literal is the default, but this may change.  */
262 # ifndef DEFAULT_QUOTING_STYLE
263 #  define DEFAULT_QUOTING_STYLE literal_quoting_style
264 # endif
265 
266 /* Names of quoting styles and their corresponding values.  */
267 extern char const *const quoting_style_args[];
268 extern enum quoting_style const quoting_style_vals[];
269 
270 struct quoting_options;
271 
272 /* The functions listed below set and use a hidden variable
273    that contains the default quoting style options.  */
274 
275 /* Allocate a new set of quoting options, with contents initially identical
276    to O if O is not null, or to the default if O is null.
277    It is the caller's responsibility to free the result.  */
278 struct quoting_options *clone_quoting_options (struct quoting_options *o)
279   _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_DEALLOC_FREE
280   _GL_ATTRIBUTE_RETURNS_NONNULL;
281 
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   _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_DEALLOC_FREE
338   _GL_ATTRIBUTE_RETURNS_NONNULL;
339 
340 /* Like quotearg_alloc, except that the length of the result,
341    excluding the terminating null byte, is stored into SIZE if it is
342    non-NULL.  The result might contain embedded null bytes if ARGSIZE
343    was not -1, SIZE was not NULL, the style of O does not use
344    backslash escapes, and the flags of O do not request elision of
345    null bytes.*/
346 char *quotearg_alloc_mem (char const *arg, size_t argsize,
347                           size_t *size, struct quoting_options const *o)
348   _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_DEALLOC_FREE
349   _GL_ATTRIBUTE_RETURNS_NONNULL;
350 
351 /* Use storage slot N to return a quoted version of the string ARG.
352    Use the default quoting options.
353    The returned value points to static storage that can be
354    reused by the next call to this function with the same value of N.
355    N must be nonnegative.  The output of all functions in the
356    quotearg_n family are guaranteed to not contain embedded null
357    bytes.*/
358 char *quotearg_n (int n, char const *arg);
359 
360 /* Equivalent to quotearg_n (0, ARG).  */
361 char *quotearg (char const *arg);
362 
363 /* Use storage slot N to return a quoted version of the argument ARG
364    of size ARGSIZE.  This is like quotearg_n (N, ARG), except it can
365    quote null bytes.  */
366 char *quotearg_n_mem (int n, char const *arg, size_t argsize);
367 
368 /* Equivalent to quotearg_n_mem (0, ARG, ARGSIZE).  */
369 char *quotearg_mem (char const *arg, size_t argsize);
370 
371 /* Use style S and storage slot N to return a quoted version of the string ARG.
372    This is like quotearg_n (N, ARG), except that it uses S with no other
373    options to specify the quoting method.  */
374 char *quotearg_n_style (int n, enum quoting_style s, char const *arg);
375 
376 /* Use style S and storage slot N to return a quoted version of the
377    argument ARG of size ARGSIZE.  This is like quotearg_n_style
378    (N, S, ARG), except it can quote null bytes.  */
379 char *quotearg_n_style_mem (int n, enum quoting_style s,
380                             char const *arg, size_t argsize);
381 
382 /* Equivalent to quotearg_n_style (0, S, ARG).  */
383 char *quotearg_style (enum quoting_style s, char const *arg);
384 
385 /* Equivalent to quotearg_n_style_mem (0, S, ARG, ARGSIZE).  */
386 char *quotearg_style_mem (enum quoting_style s,
387                           char const *arg, size_t argsize);
388 
389 /* Like quotearg (ARG), except also quote any instances of CH.
390    See set_char_quoting for a description of acceptable CH values.  */
391 char *quotearg_char (char const *arg, char ch);
392 
393 /* Like quotearg_char (ARG, CH), except it can quote null bytes.  */
394 char *quotearg_char_mem (char const *arg, size_t argsize, char ch);
395 
396 /* Equivalent to quotearg_char (ARG, ':').  */
397 char *quotearg_colon (char const *arg);
398 
399 /* Like quotearg_colon (ARG), except it can quote null bytes.  */
400 char *quotearg_colon_mem (char const *arg, size_t argsize);
401 
402 /* Like quotearg_n_style, except with ':' quoting enabled.  */
403 char *quotearg_n_style_colon (int n, enum quoting_style s, char const *arg);
404 
405 /* Like quotearg_n_style (N, S, ARG) but with S as custom_quoting_style
406    with left quote as LEFT_QUOTE and right quote as RIGHT_QUOTE.  See
407    set_custom_quoting for a description of acceptable LEFT_QUOTE and
408    RIGHT_QUOTE values.  */
409 char *quotearg_n_custom (int n, char const *left_quote,
410                          char const *right_quote, char const *arg);
411 
412 /* Like quotearg_n_custom (N, LEFT_QUOTE, RIGHT_QUOTE, ARG) except it
413    can quote null bytes.  */
414 char *quotearg_n_custom_mem (int n, char const *left_quote,
415                              char const *right_quote,
416                              char const *arg, size_t argsize);
417 
418 /* Equivalent to quotearg_n_custom (0, LEFT_QUOTE, RIGHT_QUOTE, ARG).  */
419 char *quotearg_custom (char const *left_quote, char const *right_quote,
420                        char const *arg);
421 
422 /* Equivalent to quotearg_n_custom_mem (0, LEFT_QUOTE, RIGHT_QUOTE, ARG,
423                                         ARGSIZE).  */
424 char *quotearg_custom_mem (char const *left_quote,
425                            char const *right_quote,
426                            char const *arg, size_t argsize);
427 
428 /* Free any dynamically allocated memory.  */
429 void quotearg_free (void);
430 
431 #endif /* !QUOTEARG_H_ */
432