lib/quotearg.h

   1 /* quotearg.h - quote arguments for output
   2
   3    Copyright (C) 1998-2002, 2004, 2006, 2008-2025 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 /* This file uses _GL_ATTRIBUTE_MALLOC, _GL_ATTRIBUTE_RETURNS_NONNULL.  */
  25 #if !_GL_CONFIG_H_INCLUDED
  26 # error "Please include config.h first."
  27 #endif
  28
  29 #include <stdlib.h>
  30
  31 #ifdef __cplusplus
  32 extern "C" {
  33 #endif
  34
  35
  36 /* Basic quoting styles.  For each style, an example is given on the
  37    input strings "simple", "\0 \t\n'\"\033?""?/\\", and "a:b", using
  38    quotearg_buffer, quotearg_mem, and quotearg_colon_mem with that
  39    style and the default flags and quoted characters.  Note that the
  40    examples are shown here as valid C strings rather than what
  41    displays on a terminal (with "??/" as a trigraph for "\\").  */
  42 enum quoting_style
  43   {
  44     /* Output names as-is (ls --quoting-style=literal).  Can result in
  45        embedded null bytes if QA_ELIDE_NULL_BYTES is not in
  46        effect.
  47
  48        quotearg_buffer:
  49        "simple", "\0 \t\n'\"\033??/\\", "a:b"
  50        quotearg:
  51        "simple", " \t\n'\"\033??/\\", "a:b"
  52        quotearg_colon:
  53        "simple", " \t\n'\"\033??/\\", "a:b"
  54     */
  55     literal_quoting_style,
  56
  57     /* Quote names for the shell if they contain shell metacharacters
  58        or would cause ambiguous output (ls --quoting-style=shell).
  59        Can result in embedded null bytes if QA_ELIDE_NULL_BYTES is not
  60        in effect.
  61
  62        quotearg_buffer:
  63        "simple", "'\0 \t\n'\\''\"\033??/\\'", "a:b"
  64        quotearg:
  65        "simple", "' \t\n'\\''\"\033??/\\'", "a:b"
  66        quotearg_colon:
  67        "simple", "' \t\n'\\''\"\033??/\\'", "'a:b'"
  68     */
  69     shell_quoting_style,
  70
  71     /* Quote names for the shell, even if they would normally not
  72        require quoting (ls --quoting-style=shell-always).  Can result
  73        in embedded null bytes if QA_ELIDE_NULL_BYTES is not in effect.
  74        Behaves like shell_quoting_style if QA_ELIDE_OUTER_QUOTES is in
  75        effect.
  76
  77        quotearg_buffer:
  78        "'simple'", "'\0 \t\n'\\''\"\033??/\\'", "'a:b'"
  79        quotearg:
  80        "'simple'", "' \t\n'\\''\"\033??/\\'", "'a:b'"
  81        quotearg_colon:
  82        "'simple'", "' \t\n'\\''\"\033??/\\'", "'a:b'"
  83     */
  84     shell_always_quoting_style,
  85
  86     /* Quote names for the shell if they contain shell metacharacters
  87        or other problematic characters (ls --quoting-style=shell-escape).
  88        Non printable characters are quoted using the $'...' syntax
  89        <https://www.gnu.org/software/bash/manual/html_node/ANSI_002dC-Quoting.html>,
  90        which originated in ksh93 and is widely supported by most shells,
  91        and proposed for inclusion in POSIX.
  92
  93        quotearg_buffer:
  94        "simple", "''$'\\0'' '$'\\t\\n'\\''\"'$'\\033''??/\\'", "a:b"
  95        quotearg:
  96        "simple", "''$'\\0'' '$'\\t\\n'\\''\"'$'\\033''??/\\'", "a:b"
  97        quotearg_colon:
  98        "simple", "''$'\\0'' '$'\\t\\n'\\''\"'$'\\033''??/\\'", "'a:b'"
  99     */
 100     shell_escape_quoting_style,
 101
 102     /* Quote names for the shell even if they would normally not
 103        require quoting (ls --quoting-style=shell-escape).
 104        Non printable characters are quoted using the $'...' syntax
 105        <https://www.gnu.org/software/bash/manual/html_node/ANSI_002dC-Quoting.html>,
 106        which originated in ksh93 and is widely supported by most shells,
 107        and proposed for inclusion in POSIX.  Behaves like
 108        shell_escape_quoting_style if QA_ELIDE_OUTER_QUOTES is in effect.
 109
 110        quotearg_buffer:
 111        "simple", "''$'\\0'' '$'\\t\\n'\\''\"'$'\\033''??/\'", "a:b"
 112        quotearg:
 113        "simple", "''$'\\0'' '$'\\t\\n'\\''\"'$'\\033''??/\'", "a:b"
 114        quotearg_colon:
 115        "simple", "''$'\\0'' '$'\\t\\n'\\''\"'$'\\033''??/\'", "'a:b'"
 116     */
 117     shell_escape_always_quoting_style,
 118
 119     /* Quote names as for a C language string (ls --quoting-style=c).
 120        Behaves like c_maybe_quoting_style if QA_ELIDE_OUTER_QUOTES is
 121        in effect.  Split into consecutive strings if
 122        QA_SPLIT_TRIGRAPHS.
 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_quoting_style,
 132
 133     /* Like c_quoting_style except omit the surrounding double-quote
 134        characters if no quoted characters are encountered.
 135
 136        quotearg_buffer:
 137        "simple", "\"\\0 \\t\\n'\\\"\\033??/\\\\\"", "a:b"
 138        quotearg:
 139        "simple", "\"\\0 \\t\\n'\\\"\\033??/\\\\\"", "a:b"
 140        quotearg_colon:
 141        "simple", "\"\\0 \\t\\n'\\\"\\033??/\\\\\"", "\"a:b\""
 142     */
 143     c_maybe_quoting_style,
 144
 145     /* Like c_quoting_style except always omit the surrounding
 146        double-quote characters and ignore QA_SPLIT_TRIGRAPHS
 147        (ls --quoting-style=escape).
 148
 149        quotearg_buffer:
 150        "simple", "\\0 \\t\\n'\"\\033??/\\\\", "a:b"
 151        quotearg:
 152        "simple", "\\0 \\t\\n'\"\\033??/\\\\", "a:b"
 153        quotearg_colon:
 154        "simple", "\\0 \\t\\n'\"\\033??/\\\\", "a\\:b"
 155     */
 156     escape_quoting_style,
 157
 158     /* Like clocale_quoting_style, but use single quotes in the
 159        default C locale or if the program does not use gettext
 160        (ls --quoting-style=locale).  For UTF-8 locales, quote
 161        characters will use Unicode.
 162
 163        LC_MESSAGES=C
 164        quotearg_buffer:
 165        "'simple'", "'\\0 \\t\\n\\'\"\\033??/\\\\'", "'a:b'"
 166        quotearg:
 167        "'simple'", "'\\0 \\t\\n\\'\"\\033??/\\\\'", "'a:b'"
 168        quotearg_colon:
 169        "'simple'", "'\\0 \\t\\n\\'\"\\033??/\\\\'", "'a\\:b'"
 170
 171        LC_MESSAGES=pt_PT.utf8
 172        quotearg_buffer:
 173        "\302\253simple\302\273",
 174        "\302\253\\0 \\t\\n'\"\\033??/\\\\\302\253", "\302\253a:b\302\273"
 175        quotearg:
 176        "\302\253simple\302\273",
 177        "\302\253\\0 \\t\\n'\"\\033??/\\\\\302\253", "\302\253a:b\302\273"
 178        quotearg_colon:
 179        "\302\253simple\302\273",
 180        "\302\253\\0 \\t\\n'\"\\033??/\\\\\302\253", "\302\253a\\:b\302\273"
 181     */
 182     locale_quoting_style,
 183
 184     /* Like c_quoting_style except use quotation marks appropriate for
 185        the locale and ignore QA_SPLIT_TRIGRAPHS
 186        (ls --quoting-style=clocale).
 187
 188        LC_MESSAGES=C
 189        quotearg_buffer:
 190        "\"simple\"", "\"\\0 \\t\\n'\\\"\\033??/\\\\\"", "\"a:b\""
 191        quotearg:
 192        "\"simple\"", "\"\\0 \\t\\n'\\\"\\033??/\\\\\"", "\"a:b\""
 193        quotearg_colon:
 194        "\"simple\"", "\"\\0 \\t\\n'\\\"\\033??/\\\\\"", "\"a\\:b\""
 195
 196        LC_MESSAGES=pt_PT.utf8
 197        quotearg_buffer:
 198        "\302\253simple\302\273",
 199        "\302\253\\0 \\t\\n'\"\\033??/\\\\\302\253", "\302\253a:b\302\273"
 200        quotearg:
 201        "\302\253simple\302\273",
 202        "\302\253\\0 \\t\\n'\"\\033??/\\\\\302\253", "\302\253a:b\302\273"
 203        quotearg_colon:
 204        "\302\253simple\302\273",
 205        "\302\253\\0 \\t\\n'\"\\033??/\\\\\302\253", "\302\253a\\:b\302\273"
 206     */
 207     clocale_quoting_style,
 208
 209     /* Like clocale_quoting_style except use the custom quotation marks
 210        set by set_custom_quoting.  If custom quotation marks are not
 211        set, the behavior is undefined.
 212
 213        left_quote = right_quote = "'"
 214        quotearg_buffer:
 215        "'simple'", "'\\0 \\t\\n\\'\"\\033??/\\\\'", "'a:b'"
 216        quotearg:
 217        "'simple'", "'\\0 \\t\\n\\'\"\\033??/\\\\'", "'a:b'"
 218        quotearg_colon:
 219        "'simple'", "'\\0 \\t\\n\\'\"\\033??/\\\\'", "'a\\:b'"
 220
 221        left_quote = "(" and right_quote = ")"
 222        quotearg_buffer:
 223        "(simple)", "(\\0 \\t\\n'\"\\033??/\\\\)", "(a:b)"
 224        quotearg:
 225        "(simple)", "(\\0 \\t\\n'\"\\033??/\\\\)", "(a:b)"
 226        quotearg_colon:
 227        "(simple)", "(\\0 \\t\\n'\"\\033??/\\\\)", "(a\\:b)"
 228
 229        left_quote = ":" and right_quote = " "
 230        quotearg_buffer:
 231        ":simple ", ":\\0\\ \\t\\n'\"\\033??/\\\\ ", ":a:b "
 232        quotearg:
 233        ":simple ", ":\\0\\ \\t\\n'\"\\033??/\\\\ ", ":a:b "
 234        quotearg_colon:
 235        ":simple ", ":\\0\\ \\t\\n'\"\\033??/\\\\ ", ":a\\:b "
 236
 237        left_quote = "\"'" and right_quote = "'\""
 238        Notice that this is treated as a single level of quotes or two
 239        levels where the outer quote need not be escaped within the inner
 240        quotes.  For two levels where the outer quote must be escaped
 241        within the inner quotes, you must use separate quotearg
 242        invocations.
 243        quotearg_buffer:
 244        "\"'simple'\"", "\"'\\0 \\t\\n\\'\"\\033??/\\\\'\"", "\"'a:b'\""
 245        quotearg:
 246        "\"'simple'\"", "\"'\\0 \\t\\n\\'\"\\033??/\\\\'\"", "\"'a:b'\""
 247        quotearg_colon:
 248        "\"'simple'\"", "\"'\\0 \\t\\n\\'\"\\033??/\\\\'\"", "\"'a\\:b'\""
 249     */
 250     custom_quoting_style
 251   };
 252
 253 /* Flags for use in set_quoting_flags.  */
 254 enum quoting_flags
 255   {
 256     /* Always elide null bytes from styles that do not quote them,
 257        even when the length of the result is available to the
 258        caller.  */
 259     QA_ELIDE_NULL_BYTES = 0x01,
 260
 261     /* Omit the surrounding quote characters if no escaped characters
 262        are encountered.  Note that if no other character needs
 263        escaping, then neither does the escape character.
 264        *Attention!*  This flag is unsupported in combination with the styles
 265        shell_escape_quoting_style and shell_escape_always_quoting_style
 266        (because in this situation it cannot handle strings that start
 267        with a non-printable character).  */
 268     QA_ELIDE_OUTER_QUOTES = 0x02,
 269
 270     /* In the c_quoting_style and c_maybe_quoting_style, split ANSI
 271        trigraph sequences into concatenated strings (for example,
 272        "?""?/" rather than "??/", which could be confused with
 273        "\\").  */
 274     QA_SPLIT_TRIGRAPHS = 0x04
 275   };
 276
 277 /* For now, --quoting-style=literal is the default, but this may change.  */
 278 #ifndef DEFAULT_QUOTING_STYLE
 279 # define DEFAULT_QUOTING_STYLE literal_quoting_style
 280 #endif
 281
 282 /* Names of quoting styles and their corresponding values.  */
 283 extern char const *const quoting_style_args[];
 284 extern enum quoting_style const quoting_style_vals[];
 285
 286 struct quoting_options;
 287
 288 /* The functions listed below set and use a hidden variable
 289    that contains the default quoting style options.  */
 290
 291 /* Allocate a new set of quoting options, with contents initially identical
 292    to O if O is not null, or to the default if O is null.
 293    It is the caller's responsibility to free the result.  */
 294 struct quoting_options *clone_quoting_options (struct quoting_options *o)
 295   _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_DEALLOC_FREE
 296   _GL_ATTRIBUTE_RETURNS_NONNULL;
 297
 298 /* Get the value of O's quoting style.  If O is null, use the default.  */
 299 enum quoting_style get_quoting_style (struct quoting_options const *o);
 300
 301 /* In O (or in the default if O is null),
 302    set the value of the quoting style to S.  */
 303 void set_quoting_style (struct quoting_options *o, enum quoting_style s);
 304
 305 /* In O (or in the default if O is null),
 306    set the value of the quoting options for character C to I.
 307    Return the old value.  Currently, the only values defined for I are
 308    0 (the default) and 1 (which means to quote the character even if
 309    it would not otherwise be quoted).  C must never be a digit or a
 310    letter that has special meaning after a backslash (for example, "\t"
 311    for tab).  */
 312 int set_char_quoting (struct quoting_options *o, char c, int i);
 313
 314 /* In O (or in the default if O is null),
 315    set the value of the quoting options flag to I, which can be a
 316    bitwise combination of enum quoting_flags, or 0 for default
 317    behavior.  Return the old value.  */
 318 int set_quoting_flags (struct quoting_options *o, int i);
 319
 320 /* In O (or in the default if O is null),
 321    set the value of the quoting style to custom_quoting_style,
 322    set the left quote to LEFT_QUOTE, and set the right quote to
 323    RIGHT_QUOTE.  Each of LEFT_QUOTE and RIGHT_QUOTE must be
 324    null-terminated and can be the empty string.  Because backslashes are
 325    used for escaping, it does not make sense for RIGHT_QUOTE to contain
 326    a backslash.  RIGHT_QUOTE must not begin with a digit or a letter
 327    that has special meaning after a backslash (for example, "\t" for
 328    tab).  */
 329 void set_custom_quoting (struct quoting_options *o,
 330                          char const *left_quote,
 331                          char const *right_quote);
 332
 333 /* Place into buffer BUFFER (of size BUFFERSIZE) a quoted version of
 334    argument ARG (of size ARGSIZE), using O to control quoting.
 335    If O is null, use the default.
 336    Terminate the output with a null character, and return the written
 337    size of the output, not counting the terminating null.
 338    If BUFFERSIZE is too small to store the output string, return the
 339    value that would have been returned had BUFFERSIZE been large enough.
 340    If ARGSIZE is -1, use the string length of the argument for ARGSIZE.
 341    On output, BUFFER might contain embedded null bytes if ARGSIZE was
 342    not -1, the style of O does not use backslash escapes, and the
 343    flags of O do not request elision of null bytes.*/
 344 size_t quotearg_buffer (char *restrict buffer, size_t buffersize,
 345                         char const *arg, size_t argsize,
 346                         struct quoting_options const *o);
 347
 348 /* Like quotearg_buffer, except return the result in a newly allocated
 349    buffer.  It is the caller's responsibility to free the result.  The
 350    result will not contain embedded null bytes.  */
 351 char *quotearg_alloc (char const *arg, size_t argsize,
 352                       struct quoting_options const *o)
 353   _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_DEALLOC_FREE
 354   _GL_ATTRIBUTE_RETURNS_NONNULL;
 355
 356 /* Like quotearg_alloc, except that the length of the result,
 357    excluding the terminating null byte, is stored into SIZE if it is
 358    non-NULL.  The result might contain embedded null bytes if ARGSIZE
 359    was not -1, SIZE was not NULL, the style of O does not use
 360    backslash escapes, and the flags of O do not request elision of
 361    null bytes.*/
 362 char *quotearg_alloc_mem (char const *arg, size_t argsize,
 363                           size_t *size, struct quoting_options const *o)
 364   _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_DEALLOC_FREE
 365   _GL_ATTRIBUTE_RETURNS_NONNULL;
 366
 367 /* Use storage slot N to return a quoted version of the string ARG.
 368    Use the default quoting options.
 369    The returned value points to static storage that can be
 370    reused by the next call to this function with the same value of N.
 371    N must be nonnegative.  The output of all functions in the
 372    quotearg_n family are guaranteed to not contain embedded null
 373    bytes.*/
 374 char *quotearg_n (int n, char const *arg);
 375
 376 /* Equivalent to quotearg_n (0, ARG).  */
 377 char *quotearg (char const *arg);
 378
 379 /* Use storage slot N to return a quoted version of the argument ARG
 380    of size ARGSIZE.  This is like quotearg_n (N, ARG), except it can
 381    quote null bytes.  */
 382 char *quotearg_n_mem (int n, char const *arg, size_t argsize);
 383
 384 /* Equivalent to quotearg_n_mem (0, ARG, ARGSIZE).  */
 385 char *quotearg_mem (char const *arg, size_t argsize);
 386
 387 /* Use style S and storage slot N to return a quoted version of the string ARG.
 388    This is like quotearg_n (N, ARG), except that it uses S with no other
 389    options to specify the quoting method.  */
 390 char *quotearg_n_style (int n, enum quoting_style s, char const *arg);
 391
 392 /* Use style S and storage slot N to return a quoted version of the
 393    argument ARG of size ARGSIZE.  This is like quotearg_n_style
 394    (N, S, ARG), except it can quote null bytes.  */
 395 char *quotearg_n_style_mem (int n, enum quoting_style s,
 396                             char const *arg, size_t argsize);
 397
 398 /* Equivalent to quotearg_n_style (0, S, ARG).  */
 399 char *quotearg_style (enum quoting_style s, char const *arg);
 400
 401 /* Equivalent to quotearg_n_style_mem (0, S, ARG, ARGSIZE).  */
 402 char *quotearg_style_mem (enum quoting_style s,
 403                           char const *arg, size_t argsize);
 404
 405 /* Like quotearg (ARG), except also quote any instances of CH.
 406    See set_char_quoting for a description of acceptable CH values.  */
 407 char *quotearg_char (char const *arg, char ch);
 408
 409 /* Like quotearg_char (ARG, CH), except it can quote null bytes.  */
 410 char *quotearg_char_mem (char const *arg, size_t argsize, char ch);
 411
 412 /* Equivalent to quotearg_char (ARG, ':').  */
 413 char *quotearg_colon (char const *arg);
 414
 415 /* Like quotearg_colon (ARG), except it can quote null bytes.  */
 416 char *quotearg_colon_mem (char const *arg, size_t argsize);
 417
 418 /* Like quotearg_n_style, except with ':' quoting enabled.  */
 419 char *quotearg_n_style_colon (int n, enum quoting_style s, char const *arg);
 420
 421 /* Like quotearg_n_style (N, S, ARG) but with S as custom_quoting_style
 422    with left quote as LEFT_QUOTE and right quote as RIGHT_QUOTE.  See
 423    set_custom_quoting for a description of acceptable LEFT_QUOTE and
 424    RIGHT_QUOTE values.  */
 425 char *quotearg_n_custom (int n, char const *left_quote,
 426                          char const *right_quote, char const *arg);
 427
 428 /* Like quotearg_n_custom (N, LEFT_QUOTE, RIGHT_QUOTE, ARG) except it
 429    can quote null bytes.  */
 430 char *quotearg_n_custom_mem (int n, char const *left_quote,
 431                              char const *right_quote,
 432                              char const *arg, size_t argsize);
 433
 434 /* Equivalent to quotearg_n_custom (0, LEFT_QUOTE, RIGHT_QUOTE, ARG).  */
 435 char *quotearg_custom (char const *left_quote, char const *right_quote,
 436                        char const *arg);
 437
 438 /* Equivalent to quotearg_n_custom_mem (0, LEFT_QUOTE, RIGHT_QUOTE, ARG,
 439                                         ARGSIZE).  */
 440 char *quotearg_custom_mem (char const *left_quote,
 441                            char const *right_quote,
 442                            char const *arg, size_t argsize);
 443
 444 /* Free any dynamically allocated memory.  */
 445 void quotearg_free (void);
 446
 447
 448 #ifdef __cplusplus
 449 }
 450 #endif
 451
 452 #endif /* !QUOTEARG_H_ */