1 /* gshell.c - Shell-related utilities
3 * Copyright 2000 Red Hat, Inc.
4 * g_execvpe implementation based on GNU libc execvp:
5 * Copyright 1991, 92, 95, 96, 97, 98, 99 Free Software Foundation, Inc.
7 * GLib is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public License as
9 * published by the Free Software Foundation; either version 2 of the
10 * License, or (at your option) any later version.
12 * GLib is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with GLib; see the file COPYING.LIB. If not, write
19 * to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
20 * Boston, MA 02111-1307, USA.
30 #warning "FIXME remove gettext hack"
37 g_shell_error_quark (void)
39 return g_quark_from_static_string ("g-shell-error-quark");
42 /* Single quotes preserve the literal string exactly. escape
43 * sequences are not allowed; not even \' - if you want a '
44 * in the quoted text, you have to do something like 'foo'\''bar'
46 * Double quotes allow $ ` " \ and newline to be escaped with backslash.
47 * Otherwise double quotes preserve things literally.
51 unquote_string_inplace (gchar* str, gchar** end, GError** err)
57 g_return_val_if_fail(end != NULL, FALSE);
58 g_return_val_if_fail(err == NULL || *err == NULL, FALSE);
59 g_return_val_if_fail(str != NULL, FALSE);
65 if (!(*s == '"' || *s == '\''))
67 g_set_error_literal (err,
69 G_SHELL_ERROR_BAD_QUOTING,
70 _("Quoted text doesn't begin with a quotation mark"));
75 /* Skip the initial quote mark */
78 if (quote_char == '"')
82 g_assert(s > dest); /* loop invariant */
87 /* End of the string, return now */
95 /* Possible escaped quote or \ */
110 /* not an escaped char */
113 /* ++s already done. */
125 g_assert(s > dest); /* loop invariant */
132 g_assert(s > dest); /* loop invariant */
136 /* End of the string, return now */
149 g_assert(s > dest); /* loop invariant */
153 /* If we reach here this means the close quote was never encountered */
157 g_set_error_literal (err,
159 G_SHELL_ERROR_BAD_QUOTING,
160 _("Unmatched quotation mark in command line or other shell-quoted text"));
167 * @unquoted_string: a literal string
169 * Quotes a string so that the shell (/bin/sh) will interpret the
170 * quoted string to mean @unquoted_string. If you pass a filename to
171 * the shell, for example, you should first quote it with this
172 * function. The return value must be freed with g_free(). The
173 * quoting style used is undefined (single or double quotes may be
176 * Return value: quoted string
179 g_shell_quote (const gchar *unquoted_string)
181 /* We always use single quotes, because the algorithm is cheesier.
182 * We could use double if we felt like it, that might be more
189 g_return_val_if_fail (unquoted_string != NULL, NULL);
191 dest = g_string_new ("'");
195 /* could speed this up a lot by appending chunks of text at a
200 /* Replace literal ' with a close ', a \', and a open ' */
202 g_string_append (dest, "'\\''");
204 g_string_append_c (dest, *p);
209 /* close the quote */
210 g_string_append_c (dest, '\'');
212 return g_string_free (dest, FALSE);
217 * @quoted_string: shell-quoted string
218 * @error: error return location or NULL
220 * Unquotes a string as the shell (/bin/sh) would. Only handles
221 * quotes; if a string contains file globs, arithmetic operators,
222 * variables, backticks, redirections, or other special-to-the-shell
223 * features, the result will be different from the result a real shell
224 * would produce (the variables, backticks, etc. will be passed
225 * through literally instead of being expanded). This function is
226 * guaranteed to succeed if applied to the result of
227 * g_shell_quote(). If it fails, it returns %NULL and sets the
228 * error. The @quoted_string need not actually contain quoted or
229 * escaped text; g_shell_unquote() simply goes through the string and
230 * unquotes/unescapes anything that the shell would. Both single and
231 * double quotes are handled, as are escapes including escaped
232 * newlines. The return value must be freed with g_free(). Possible
233 * errors are in the #G_SHELL_ERROR domain.
235 * Shell quoting rules are a bit strange. Single quotes preserve the
236 * literal string exactly. escape sequences are not allowed; not even
237 * \' - if you want a ' in the quoted text, you have to do something
238 * like 'foo'\''bar'. Double quotes allow $, `, ", \, and newline to
239 * be escaped with backslash. Otherwise double quotes preserve things
242 * Return value: an unquoted string
245 g_shell_unquote (const gchar *quoted_string,
253 g_return_val_if_fail (quoted_string != NULL, NULL);
255 unquoted = g_strdup (quoted_string);
259 retval = g_string_new (NULL);
261 /* The loop allows cases such as
262 * "foo"blah blah'bar'woo foo"baz"la la la\'\''foo'
266 /* Append all non-quoted chars, honoring backslash escape
269 while (*start && !(*start == '"' || *start == '\''))
273 /* all characters can get escaped by backslash,
274 * except newline, which is removed if it follows
275 * a backslash outside of quotes
282 g_string_append_c (retval, *start);
288 g_string_append_c (retval, *start);
295 if (!unquote_string_inplace (start, &end, error))
301 g_string_append (retval, start);
308 return g_string_free (retval, FALSE);
311 g_assert (error == NULL || *error != NULL);
314 g_string_free (retval, TRUE);
318 /* g_parse_argv() does a semi-arbitrary weird subset of the way
319 * the shell parses a command line. We don't do variable expansion,
320 * don't understand that operators are tokens, don't do tilde expansion,
321 * don't do command substitution, no arithmetic expansion, IFS gets ignored,
322 * don't do filename globs, don't remove redirection stuff, etc.
324 * READ THE UNIX98 SPEC on "Shell Command Language" before changing
325 * the behavior of this code.
327 * Steps to parsing the argv string:
329 * - tokenize the string (but since we ignore operators,
330 * our tokenization may diverge from what the shell would do)
331 * note that tokenization ignores the internals of a quoted
332 * word and it always splits on spaces, not on IFS even
333 * if we used IFS. We also ignore "end of input indicator"
334 * (I guess this is control-D?)
336 * Tokenization steps, from UNIX98 with operator stuff removed,
339 * 1) "If the current character is backslash, single-quote or
340 * double-quote (\, ' or ") and it is not quoted, it will affect
341 * quoting for subsequent characters up to the end of the quoted
342 * text. The rules for quoting are as described in Quoting
343 * . During token recognition no substitutions will be actually
344 * performed, and the result token will contain exactly the
345 * characters that appear in the input (except for newline
346 * character joining), unmodified, including any embedded or
347 * enclosing quotes or substitution operators, between the quote
348 * mark and the end of the quoted text. The token will not be
349 * delimited by the end of the quoted field."
351 * 2) "If the current character is an unquoted newline character,
352 * the current token will be delimited."
354 * 3) "If the current character is an unquoted blank character, any
355 * token containing the previous character is delimited and the
356 * current character will be discarded."
358 * 4) "If the previous character was part of a word, the current
359 * character will be appended to that word."
361 * 5) "If the current character is a "#", it and all subsequent
362 * characters up to, but excluding, the next newline character
363 * will be discarded as a comment. The newline character that
364 * ends the line is not considered part of the comment. The
365 * "#" starts a comment only when it is at the beginning of a
366 * token. Since the search for the end-of-comment does not
367 * consider an escaped newline character specially, a comment
368 * cannot be continued to the next line."
370 * 6) "The current character will be used as the start of a new word."
373 * - for each token (word), perform portions of word expansion, namely
374 * field splitting (using default whitespace IFS) and quote
375 * removal. Field splitting may increase the number of words.
376 * Quote removal does not increase the number of words.
378 * "If the complete expansion appropriate for a word results in an
379 * empty field, that empty field will be deleted from the list of
380 * fields that form the completely expanded command, unless the
381 * original word contained single-quote or double-quote characters."
388 ensure_token (GString **token)
391 *token = g_string_new (NULL);
395 delimit_token (GString **token,
401 *retval = g_slist_prepend (*retval, g_string_free (*token, FALSE));
407 tokenize_command_line (const gchar *command_line,
412 GString *current_token = NULL;
413 GSList *retval = NULL;
416 current_quote = '\0';
422 if (current_quote == '\\')
426 /* we append nothing; backslash-newline become nothing */
430 /* we append the backslash and the current char,
431 * to be interpreted later after tokenization
433 ensure_token (¤t_token);
434 g_string_append_c (current_token, '\\');
435 g_string_append_c (current_token, *p);
438 current_quote = '\0';
440 else if (current_quote == '#')
442 /* Discard up to and including next newline */
443 while (*p && *p != '\n')
446 current_quote = '\0';
451 else if (current_quote)
453 if (*p == current_quote &&
454 /* check that it isn't an escaped double quote */
455 !(current_quote == '"' && quoted))
457 /* close the quote */
458 current_quote = '\0';
461 /* Everything inside quotes, and the close quote,
462 * gets appended literally.
465 ensure_token (¤t_token);
466 g_string_append_c (current_token, *p);
473 delimit_token (¤t_token, &retval);
478 /* If the current token contains the previous char, delimit
479 * the current token. A nonzero length
480 * token should always contain the previous char.
483 current_token->len > 0)
485 delimit_token (¤t_token, &retval);
488 /* discard all unquoted blanks (don't add them to a token) */
492 /* single/double quotes are appended to the token,
493 * escapes are maybe appended next time through the loop,
494 * comment chars are never appended.
499 ensure_token (¤t_token);
500 g_string_append_c (current_token, *p);
510 /* Combines rules 4) and 6) - if we have a token, append to it,
511 * otherwise create a new token.
513 ensure_token (¤t_token);
514 g_string_append_c (current_token, *p);
519 /* We need to count consecutive backslashes mod 2,
520 * to detect escaped doublequotes.
530 delimit_token (¤t_token, &retval);
534 if (current_quote == '\\')
537 G_SHELL_ERROR_BAD_QUOTING,
538 _("Text ended just after a '\\' character."
539 " (The text was '%s')"),
544 G_SHELL_ERROR_BAD_QUOTING,
545 _("Text ended before matching quote was found for %c."
546 " (The text was '%s')"),
547 current_quote, command_line);
554 g_set_error_literal (error,
556 G_SHELL_ERROR_EMPTY_STRING,
557 _("Text was empty (or contained only whitespace)"));
562 /* we appended backward */
563 retval = g_slist_reverse (retval);
568 g_assert (error == NULL || *error != NULL);
572 g_slist_foreach (retval, (GFunc)g_free, NULL);
573 g_slist_free (retval);
580 * g_shell_parse_argv:
581 * @command_line: command line to parse
582 * @argcp: return location for number of args
583 * @argvp: return location for array of args
584 * @error: return location for error
586 * Parses a command line into an argument vector, in much the same way
587 * the shell would, but without many of the expansions the shell would
588 * perform (variable expansion, globs, operators, filename expansion,
589 * etc. are not supported). The results are defined to be the same as
590 * those you would get from a UNIX98 /bin/sh, as long as the input
591 * contains none of the unsupported shell expansions. If the input
592 * does contain such expansions, they are passed through
593 * literally. Possible errors are those from the #G_SHELL_ERROR
594 * domain. Free the returned vector with g_strfreev().
596 * Return value: %TRUE on success, %FALSE if error set
599 g_shell_parse_argv (const gchar *command_line,
604 /* Code based on poptParseArgvString() from libpopt */
607 GSList *tokens = NULL;
611 g_return_val_if_fail (command_line != NULL, FALSE);
613 tokens = tokenize_command_line (command_line, error);
617 /* Because we can't have introduced any new blank space into the
618 * tokens (we didn't do any new expansions), we don't need to
619 * perform field splitting. If we were going to honor IFS or do any
620 * expansions, we would have to do field splitting on each word
621 * here. Also, if we were going to do any expansion we would need to
622 * remove any zero-length words that didn't contain quotes
623 * originally; but since there's no expansion we know all words have
624 * nonzero length, unless they contain quotes.
626 * So, we simply remove quotes, and don't do any field splitting or
627 * empty word removal, since we know there was no way to introduce
631 argc = g_slist_length (tokens);
632 argv = g_new0 (gchar*, argc + 1);
637 argv[i] = g_shell_unquote (tmp_list->data, error);
639 /* Since we already checked that quotes matched up in the
640 * tokenizer, this shouldn't be possible to reach I guess.
645 tmp_list = g_slist_next (tmp_list);
649 g_slist_foreach (tokens, (GFunc)g_free, NULL);
650 g_slist_free (tokens);
664 g_assert (error == NULL || *error != NULL);
666 g_slist_foreach (tokens, (GFunc) g_free, NULL);
667 g_slist_free (tokens);
672 #define __G_SHELL_C__
673 #include "galiasdef.c"