| /* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */ |
| /* dbus-shell.c Shell command line utility functions. |
| * |
| * Copyright (C) 2002, 2003 Red Hat, Inc. |
| * Copyright (C) 2003 CodeFactory AB |
| * |
| * Licensed under the Academic Free License version 2.1 |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| * |
| */ |
| |
| #include <config.h> |
| #include <string.h> |
| #include "dbus-internals.h" |
| #include "dbus-list.h" |
| #include "dbus-memory.h" |
| #include "dbus-protocol.h" |
| #include "dbus-shell.h" |
| #include "dbus-string.h" |
| |
| /* Single quotes preserve the literal string exactly. escape |
| * sequences are not allowed; not even \' - if you want a ' |
| * in the quoted text, you have to do something like 'foo'\''bar' |
| * |
| * Double quotes allow $ ` " \ and newline to be escaped with backslash. |
| * Otherwise double quotes preserve things literally. |
| */ |
| |
| static dbus_bool_t |
| unquote_string_inplace (char* str, char** end) |
| { |
| char* dest; |
| char* s; |
| char quote_char; |
| |
| dest = s = str; |
| |
| quote_char = *s; |
| |
| if (!(*s == '"' || *s == '\'')) |
| { |
| *end = str; |
| return FALSE; |
| } |
| |
| /* Skip the initial quote mark */ |
| ++s; |
| |
| if (quote_char == '"') |
| { |
| while (*s) |
| { |
| _dbus_assert(s > dest); /* loop invariant */ |
| |
| switch (*s) |
| { |
| case '"': |
| /* End of the string, return now */ |
| *dest = '\0'; |
| ++s; |
| *end = s; |
| return TRUE; |
| |
| case '\\': |
| /* Possible escaped quote or \ */ |
| ++s; |
| switch (*s) |
| { |
| case '"': |
| case '\\': |
| case '`': |
| case '$': |
| case '\n': |
| *dest = *s; |
| ++s; |
| ++dest; |
| break; |
| |
| default: |
| /* not an escaped char */ |
| *dest = '\\'; |
| ++dest; |
| /* ++s already done. */ |
| break; |
| } |
| break; |
| |
| default: |
| *dest = *s; |
| ++dest; |
| ++s; |
| break; |
| } |
| |
| _dbus_assert(s > dest); /* loop invariant */ |
| } |
| } |
| else |
| { |
| while (*s) |
| { |
| _dbus_assert(s > dest); /* loop invariant */ |
| |
| if (*s == '\'') |
| { |
| /* End of the string, return now */ |
| *dest = '\0'; |
| ++s; |
| *end = s; |
| return TRUE; |
| } |
| else |
| { |
| *dest = *s; |
| ++dest; |
| ++s; |
| } |
| |
| _dbus_assert(s > dest); /* loop invariant */ |
| } |
| } |
| |
| /* If we reach here this means the close quote was never encountered */ |
| |
| *dest = '\0'; |
| |
| *end = s; |
| return FALSE; |
| } |
| |
| /** |
| * Unquotes a string as the shell (/bin/sh) would. Only handles |
| * quotes; if a string contains file globs, arithmetic operators, |
| * variables, backticks, redirections, or other special-to-the-shell |
| * features, the result will be different from the result a real shell |
| * would produce (the variables, backticks, etc. will be passed |
| * through literally instead of being expanded). This function is |
| * guaranteed to succeed if applied to the result of |
| * _dbus_shell_quote(). If it fails, it returns %NULL. |
| * The @quoted_string need not actually contain quoted or |
| * escaped text; _dbus_shell_unquote() simply goes through the string and |
| * unquotes/unescapes anything that the shell would. Both single and |
| * double quotes are handled, as are escapes including escaped |
| * newlines. The return value must be freed with dbus_free(). |
| * |
| * Shell quoting rules are a bit strange. Single quotes preserve the |
| * literal string exactly. escape sequences are not allowed; not even |
| * \' - if you want a ' in the quoted text, you have to do something |
| * like 'foo'\''bar'. Double quotes allow $, `, ", \, and newline to |
| * be escaped with backslash. Otherwise double quotes preserve things |
| * literally. |
| * |
| * @quoted_string: shell-quoted string |
| **/ |
| char* |
| _dbus_shell_unquote (const char *quoted_string) |
| { |
| char *unquoted; |
| char *end; |
| char *start; |
| char *ret; |
| DBusString retval; |
| |
| unquoted = _dbus_strdup (quoted_string); |
| if (unquoted == NULL) |
| return NULL; |
| |
| start = unquoted; |
| end = unquoted; |
| if (!_dbus_string_init (&retval)) |
| { |
| dbus_free (unquoted); |
| return NULL; |
| } |
| |
| /* The loop allows cases such as |
| * "foo"blah blah'bar'woo foo"baz"la la la\'\''foo' |
| */ |
| while (*start) |
| { |
| /* Append all non-quoted chars, honoring backslash escape |
| */ |
| |
| while (*start && !(*start == '"' || *start == '\'')) |
| { |
| if (*start == '\\') |
| { |
| /* all characters can get escaped by backslash, |
| * except newline, which is removed if it follows |
| * a backslash outside of quotes |
| */ |
| |
| ++start; |
| if (*start) |
| { |
| if (*start != '\n') |
| { |
| if (!_dbus_string_append_byte (&retval, *start)) |
| goto error; |
| } |
| ++start; |
| } |
| } |
| else |
| { |
| if (!_dbus_string_append_byte (&retval, *start)) |
| goto error; |
| ++start; |
| } |
| } |
| |
| if (*start) |
| { |
| if (!unquote_string_inplace (start, &end)) |
| goto error; |
| else |
| { |
| if (!_dbus_string_append (&retval, start)) |
| goto error; |
| start = end; |
| } |
| } |
| } |
| |
| ret = _dbus_strdup (_dbus_string_get_data (&retval)); |
| if (!ret) |
| goto error; |
| |
| dbus_free (unquoted); |
| _dbus_string_free (&retval); |
| |
| return ret; |
| |
| error: |
| dbus_free (unquoted); |
| _dbus_string_free (&retval); |
| return NULL; |
| } |
| |
| /* _dbus_shell_parse_argv() does a semi-arbitrary weird subset of the way |
| * the shell parses a command line. We don't do variable expansion, |
| * don't understand that operators are tokens, don't do tilde expansion, |
| * don't do command substitution, no arithmetic expansion, IFS gets ignored, |
| * don't do filename globs, don't remove redirection stuff, etc. |
| * |
| * READ THE UNIX98 SPEC on "Shell Command Language" before changing |
| * the behavior of this code. |
| * |
| * Steps to parsing the argv string: |
| * |
| * - tokenize the string (but since we ignore operators, |
| * our tokenization may diverge from what the shell would do) |
| * note that tokenization ignores the internals of a quoted |
| * word and it always splits on spaces, not on IFS even |
| * if we used IFS. We also ignore "end of input indicator" |
| * (I guess this is control-D?) |
| * |
| * Tokenization steps, from UNIX98 with operator stuff removed, |
| * are: |
| * |
| * 1) "If the current character is backslash, single-quote or |
| * double-quote (\, ' or ") and it is not quoted, it will affect |
| * quoting for subsequent characters up to the end of the quoted |
| * text. The rules for quoting are as described in Quoting |
| * . During token recognition no substitutions will be actually |
| * performed, and the result token will contain exactly the |
| * characters that appear in the input (except for newline |
| * character joining), unmodified, including any embedded or |
| * enclosing quotes or substitution operators, between the quote |
| * mark and the end of the quoted text. The token will not be |
| * delimited by the end of the quoted field." |
| * |
| * 2) "If the current character is an unquoted newline character, |
| * the current token will be delimited." |
| * |
| * 3) "If the current character is an unquoted blank character, any |
| * token containing the previous character is delimited and the |
| * current character will be discarded." |
| * |
| * 4) "If the previous character was part of a word, the current |
| * character will be appended to that word." |
| * |
| * 5) "If the current character is a "#", it and all subsequent |
| * characters up to, but excluding, the next newline character |
| * will be discarded as a comment. The newline character that |
| * ends the line is not considered part of the comment. The |
| * "#" starts a comment only when it is at the beginning of a |
| * token. Since the search for the end-of-comment does not |
| * consider an escaped newline character specially, a comment |
| * cannot be continued to the next line." |
| * |
| * 6) "The current character will be used as the start of a new word." |
| * |
| * |
| * - for each token (word), perform portions of word expansion, namely |
| * field splitting (using default whitespace IFS) and quote |
| * removal. Field splitting may increase the number of words. |
| * Quote removal does not increase the number of words. |
| * |
| * "If the complete expansion appropriate for a word results in an |
| * empty field, that empty field will be deleted from the list of |
| * fields that form the completely expanded command, unless the |
| * original word contained single-quote or double-quote characters." |
| * - UNIX98 spec |
| * |
| * |
| */ |
| |
| static dbus_bool_t |
| delimit_token (DBusString *token, |
| DBusList **retval, |
| DBusError *error) |
| { |
| char *str; |
| |
| str = _dbus_strdup (_dbus_string_get_data (token)); |
| if (!str) |
| { |
| _DBUS_SET_OOM (error); |
| return FALSE; |
| } |
| |
| if (!_dbus_list_append (retval, str)) |
| { |
| dbus_free (str); |
| _DBUS_SET_OOM (error); |
| return FALSE; |
| } |
| |
| return TRUE; |
| } |
| |
| static DBusList* |
| tokenize_command_line (const char *command_line, DBusError *error) |
| { |
| char current_quote; |
| const char *p; |
| DBusString current_token; |
| DBusList *retval = NULL; |
| dbus_bool_t quoted;; |
| |
| current_quote = '\0'; |
| quoted = FALSE; |
| p = command_line; |
| |
| if (!_dbus_string_init (¤t_token)) |
| { |
| _DBUS_SET_OOM (error); |
| return NULL; |
| } |
| |
| while (*p) |
| { |
| if (current_quote == '\\') |
| { |
| if (*p == '\n') |
| { |
| /* we append nothing; backslash-newline become nothing */ |
| } |
| else |
| { |
| if (!_dbus_string_append_byte (¤t_token, '\\') || |
| !_dbus_string_append_byte (¤t_token, *p)) |
| { |
| _DBUS_SET_OOM (error); |
| goto error; |
| } |
| } |
| |
| current_quote = '\0'; |
| } |
| else if (current_quote == '#') |
| { |
| /* Discard up to and including next newline */ |
| while (*p && *p != '\n') |
| ++p; |
| |
| current_quote = '\0'; |
| |
| if (*p == '\0') |
| break; |
| } |
| else if (current_quote) |
| { |
| if (*p == current_quote && |
| /* check that it isn't an escaped double quote */ |
| !(current_quote == '"' && quoted)) |
| { |
| /* close the quote */ |
| current_quote = '\0'; |
| } |
| |
| /* Everything inside quotes, and the close quote, |
| * gets appended literally. |
| */ |
| |
| if (!_dbus_string_append_byte (¤t_token, *p)) |
| { |
| _DBUS_SET_OOM (error); |
| goto error; |
| } |
| } |
| else |
| { |
| switch (*p) |
| { |
| case '\n': |
| if (!delimit_token (¤t_token, &retval, error)) |
| goto error; |
| |
| _dbus_string_free (¤t_token); |
| |
| if (!_dbus_string_init (¤t_token)) |
| { |
| _DBUS_SET_OOM (error); |
| goto init_error; |
| } |
| |
| break; |
| |
| case ' ': |
| case '\t': |
| /* If the current token contains the previous char, delimit |
| * the current token. A nonzero length |
| * token should always contain the previous char. |
| */ |
| if (_dbus_string_get_length (¤t_token) > 0) |
| { |
| if (!delimit_token (¤t_token, &retval, error)) |
| goto error; |
| |
| _dbus_string_free (¤t_token); |
| |
| if (!_dbus_string_init (¤t_token)) |
| { |
| _DBUS_SET_OOM (error); |
| goto init_error; |
| } |
| |
| } |
| |
| /* discard all unquoted blanks (don't add them to a token) */ |
| break; |
| |
| |
| /* single/double quotes are appended to the token, |
| * escapes are maybe appended next time through the loop, |
| * comment chars are never appended. |
| */ |
| |
| case '\'': |
| case '"': |
| if (!_dbus_string_append_byte (¤t_token, *p)) |
| { |
| _DBUS_SET_OOM (error); |
| goto error; |
| } |
| |
| /* FALL THRU */ |
| |
| case '#': |
| case '\\': |
| current_quote = *p; |
| break; |
| |
| default: |
| /* Combines rules 4) and 6) - if we have a token, append to it, |
| * otherwise create a new token. |
| */ |
| if (!_dbus_string_append_byte (¤t_token, *p)) |
| { |
| _DBUS_SET_OOM (error); |
| goto error; |
| } |
| break; |
| } |
| } |
| |
| /* We need to count consecutive backslashes mod 2, |
| * to detect escaped doublequotes. |
| */ |
| if (*p != '\\') |
| quoted = FALSE; |
| else |
| quoted = !quoted; |
| |
| ++p; |
| } |
| |
| if (!delimit_token (¤t_token, &retval, error)) |
| goto error; |
| |
| if (current_quote) |
| { |
| dbus_set_error_const (error, DBUS_ERROR_INVALID_ARGS, "Unclosed quotes in command line"); |
| goto error; |
| } |
| |
| if (retval == NULL) |
| { |
| dbus_set_error_const (error, DBUS_ERROR_INVALID_ARGS, "No tokens found in command line"); |
| goto error; |
| } |
| |
| _dbus_string_free (¤t_token); |
| |
| return retval; |
| |
| error: |
| _dbus_string_free (¤t_token); |
| |
| init_error: |
| if (retval) |
| { |
| _dbus_list_foreach (&retval, (DBusForeachFunction) dbus_free, NULL); |
| _dbus_list_clear (&retval); |
| } |
| |
| return NULL; |
| } |
| |
| /** |
| * _dbus_shell_parse_argv: |
| * |
| * Parses a command line into an argument vector, in much the same way |
| * the shell would, but without many of the expansions the shell would |
| * perform (variable expansion, globs, operators, filename expansion, |
| * etc. are not supported). The results are defined to be the same as |
| * those you would get from a UNIX98 /bin/sh, as long as the input |
| * contains none of the unsupported shell expansions. If the input |
| * does contain such expansions, they are passed through |
| * literally. Free the returned vector with dbus_free_string_array(). |
| * |
| * @command_line: command line to parse |
| * @argcp: return location for number of args |
| * @argvp: return location for array of args |
| * @error: error information |
| **/ |
| dbus_bool_t |
| _dbus_shell_parse_argv (const char *command_line, |
| int *argcp, |
| char ***argvp, |
| DBusError *error) |
| { |
| /* Code based on poptParseArgvString() from libpopt */ |
| int argc = 0; |
| char **argv = NULL; |
| DBusList *tokens = NULL; |
| int i; |
| DBusList *tmp_list; |
| |
| if (!command_line) |
| { |
| _dbus_verbose ("Command line is NULL\n"); |
| return FALSE; |
| } |
| |
| tokens = tokenize_command_line (command_line, error); |
| if (tokens == NULL) |
| { |
| _dbus_verbose ("No tokens for command line '%s'\n", command_line); |
| return FALSE; |
| } |
| |
| /* Because we can't have introduced any new blank space into the |
| * tokens (we didn't do any new expansions), we don't need to |
| * perform field splitting. If we were going to honor IFS or do any |
| * expansions, we would have to do field splitting on each word |
| * here. Also, if we were going to do any expansion we would need to |
| * remove any zero-length words that didn't contain quotes |
| * originally; but since there's no expansion we know all words have |
| * nonzero length, unless they contain quotes. |
| * |
| * So, we simply remove quotes, and don't do any field splitting or |
| * empty word removal, since we know there was no way to introduce |
| * such things. |
| */ |
| |
| argc = _dbus_list_get_length (&tokens); |
| argv = dbus_new (char *, argc + 1); |
| if (!argv) |
| { |
| _DBUS_SET_OOM (error); |
| goto error; |
| } |
| |
| i = 0; |
| tmp_list = tokens; |
| while (tmp_list) |
| { |
| argv[i] = _dbus_shell_unquote (tmp_list->data); |
| |
| if (!argv[i]) |
| { |
| int j; |
| for (j = 0; j < i; j++) |
| dbus_free(argv[j]); |
| |
| dbus_free (argv); |
| _DBUS_SET_OOM (error); |
| goto error; |
| } |
| |
| tmp_list = _dbus_list_get_next_link (&tokens, tmp_list); |
| ++i; |
| } |
| argv[argc] = NULL; |
| |
| _dbus_list_foreach (&tokens, (DBusForeachFunction) dbus_free, NULL); |
| _dbus_list_clear (&tokens); |
| |
| if (argcp) |
| *argcp = argc; |
| |
| if (argvp) |
| *argvp = argv; |
| else |
| dbus_free_string_array (argv); |
| |
| return TRUE; |
| |
| error: |
| _dbus_list_foreach (&tokens, (DBusForeachFunction) dbus_free, NULL); |
| _dbus_list_clear (&tokens); |
| |
| return FALSE; |
| |
| } |