| /* gshell.c - Shell-related utilities |
| * |
| * Copyright 2000 Red Hat, Inc. |
| * g_execvpe implementation based on GNU libc execvp: |
| * Copyright 1991, 92, 95, 96, 97, 98, 99 Free Software Foundation, Inc. |
| * |
| * GLib is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public License as |
| * published by the Free Software Foundation; either version 2 of the |
| * License, or (at your option) any later version. |
| * |
| * GLib 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 |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with GLib; see the file COPYING.LIB. If not, write |
| * to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
| * Boston, MA 02111-1307, USA. |
| */ |
| |
| #include "config.h" |
| |
| #include <string.h> |
| |
| #include "gshell.h" |
| |
| #include "gslist.h" |
| #include "gstrfuncs.h" |
| #include "gstring.h" |
| #include "gtestutils.h" |
| #include "glibintl.h" |
| #include "gthread.h" |
| |
| /** |
| * SECTION:shell |
| * @title: Shell-related Utilities |
| * @short_description: shell-like commandline handling |
| * |
| * GLib provides the functions g_shell_quote() and g_shell_unquote() |
| * to handle shell-like quoting in strings. The function g_shell_parse_argv() |
| * parses a string similar to the way a POSIX shell (/bin/sh) would. |
| * |
| * Note that string handling in shells has many obscure and historical |
| * corner-cases which these functions do not necessarily reproduce. They |
| * are good enough in practice, though. |
| */ |
| |
| /** |
| * G_SHELL_ERROR: |
| * |
| * Error domain for shell functions. Errors in this domain will be from |
| * the #GShellError enumeration. See #GError for information on error |
| * domains. |
| **/ |
| |
| /** |
| * GShellError: |
| * @G_SHELL_ERROR_BAD_QUOTING: Mismatched or otherwise mangled quoting. |
| * @G_SHELL_ERROR_EMPTY_STRING: String to be parsed was empty. |
| * @G_SHELL_ERROR_FAILED: Some other error. |
| * |
| * Error codes returned by shell functions. |
| **/ |
| G_DEFINE_QUARK (g-shell-error-quark, g_shell_error) |
| |
| /* 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 gboolean |
| unquote_string_inplace (gchar* str, gchar** end, GError** err) |
| { |
| gchar* dest; |
| gchar* s; |
| gchar quote_char; |
| |
| g_return_val_if_fail(end != NULL, FALSE); |
| g_return_val_if_fail(err == NULL || *err == NULL, FALSE); |
| g_return_val_if_fail(str != NULL, FALSE); |
| |
| dest = s = str; |
| |
| quote_char = *s; |
| |
| if (!(*s == '"' || *s == '\'')) |
| { |
| g_set_error_literal (err, |
| G_SHELL_ERROR, |
| G_SHELL_ERROR_BAD_QUOTING, |
| _("Quoted text doesn't begin with a quotation mark")); |
| *end = str; |
| return FALSE; |
| } |
| |
| /* Skip the initial quote mark */ |
| ++s; |
| |
| if (quote_char == '"') |
| { |
| while (*s) |
| { |
| g_assert(s > dest); /* loop invariant */ |
| |
| switch (*s) |
| { |
| case '"': |
| /* End of the string, return now */ |
| *dest = '\0'; |
| ++s; |
| *end = s; |
| return TRUE; |
| break; |
| |
| 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; |
| } |
| |
| g_assert(s > dest); /* loop invariant */ |
| } |
| } |
| else |
| { |
| while (*s) |
| { |
| g_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; |
| } |
| |
| g_assert(s > dest); /* loop invariant */ |
| } |
| } |
| |
| /* If we reach here this means the close quote was never encountered */ |
| |
| *dest = '\0'; |
| |
| g_set_error_literal (err, |
| G_SHELL_ERROR, |
| G_SHELL_ERROR_BAD_QUOTING, |
| _("Unmatched quotation mark in command line or other shell-quoted text")); |
| *end = s; |
| return FALSE; |
| } |
| |
| /** |
| * g_shell_quote: |
| * @unquoted_string: a literal string |
| * |
| * Quotes a string so that the shell (/bin/sh) will interpret the |
| * quoted string to mean @unquoted_string. If you pass a filename to |
| * the shell, for example, you should first quote it with this |
| * function. The return value must be freed with g_free(). The |
| * quoting style used is undefined (single or double quotes may be |
| * used). |
| * |
| * Returns: quoted string |
| **/ |
| gchar* |
| g_shell_quote (const gchar *unquoted_string) |
| { |
| /* We always use single quotes, because the algorithm is cheesier. |
| * We could use double if we felt like it, that might be more |
| * human-readable. |
| */ |
| |
| const gchar *p; |
| GString *dest; |
| |
| g_return_val_if_fail (unquoted_string != NULL, NULL); |
| |
| dest = g_string_new ("'"); |
| |
| p = unquoted_string; |
| |
| /* could speed this up a lot by appending chunks of text at a |
| * time. |
| */ |
| while (*p) |
| { |
| /* Replace literal ' with a close ', a \', and a open ' */ |
| if (*p == '\'') |
| g_string_append (dest, "'\\''"); |
| else |
| g_string_append_c (dest, *p); |
| |
| ++p; |
| } |
| |
| /* close the quote */ |
| g_string_append_c (dest, '\''); |
| |
| return g_string_free (dest, FALSE); |
| } |
| |
| /** |
| * g_shell_unquote: |
| * @quoted_string: shell-quoted string |
| * @error: error return location or NULL |
| * |
| * 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 |
| * g_shell_quote(). If it fails, it returns %NULL and sets the |
| * error. The @quoted_string need not actually contain quoted or |
| * escaped text; g_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 g_free(). Possible |
| * errors are in the #G_SHELL_ERROR domain. |
| * |
| * 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. |
| * |
| * Returns: an unquoted string |
| **/ |
| gchar* |
| g_shell_unquote (const gchar *quoted_string, |
| GError **error) |
| { |
| gchar *unquoted; |
| gchar *end; |
| gchar *start; |
| GString *retval; |
| |
| g_return_val_if_fail (quoted_string != NULL, NULL); |
| |
| unquoted = g_strdup (quoted_string); |
| |
| start = unquoted; |
| end = unquoted; |
| retval = g_string_new (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') |
| g_string_append_c (retval, *start); |
| ++start; |
| } |
| } |
| else |
| { |
| g_string_append_c (retval, *start); |
| ++start; |
| } |
| } |
| |
| if (*start) |
| { |
| if (!unquote_string_inplace (start, &end, error)) |
| { |
| goto error; |
| } |
| else |
| { |
| g_string_append (retval, start); |
| start = end; |
| } |
| } |
| } |
| |
| g_free (unquoted); |
| return g_string_free (retval, FALSE); |
| |
| error: |
| g_assert (error == NULL || *error != NULL); |
| |
| g_free (unquoted); |
| g_string_free (retval, TRUE); |
| return NULL; |
| } |
| |
| /* g_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 inline void |
| ensure_token (GString **token) |
| { |
| if (*token == NULL) |
| *token = g_string_new (NULL); |
| } |
| |
| static void |
| delimit_token (GString **token, |
| GSList **retval) |
| { |
| if (*token == NULL) |
| return; |
| |
| *retval = g_slist_prepend (*retval, g_string_free (*token, FALSE)); |
| |
| *token = NULL; |
| } |
| |
| static GSList* |
| tokenize_command_line (const gchar *command_line, |
| GError **error) |
| { |
| gchar current_quote; |
| const gchar *p; |
| GString *current_token = NULL; |
| GSList *retval = NULL; |
| gboolean quoted; |
| |
| current_quote = '\0'; |
| quoted = FALSE; |
| p = command_line; |
| |
| while (*p) |
| { |
| if (current_quote == '\\') |
| { |
| if (*p == '\n') |
| { |
| /* we append nothing; backslash-newline become nothing */ |
| } |
| else |
| { |
| /* we append the backslash and the current char, |
| * to be interpreted later after tokenization |
| */ |
| ensure_token (¤t_token); |
| g_string_append_c (current_token, '\\'); |
| g_string_append_c (current_token, *p); |
| } |
| |
| 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. |
| */ |
| |
| ensure_token (¤t_token); |
| g_string_append_c (current_token, *p); |
| } |
| else |
| { |
| switch (*p) |
| { |
| case '\n': |
| delimit_token (¤t_token, &retval); |
| 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 (current_token && |
| current_token->len > 0) |
| { |
| delimit_token (¤t_token, &retval); |
| } |
| |
| /* 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 '"': |
| ensure_token (¤t_token); |
| g_string_append_c (current_token, *p); |
| |
| /* FALL THRU */ |
| case '\\': |
| current_quote = *p; |
| break; |
| |
| case '#': |
| if (p == command_line) |
| { /* '#' was the first char */ |
| current_quote = *p; |
| break; |
| } |
| switch(*(p-1)) |
| { |
| case ' ': |
| case '\n': |
| case '\0': |
| current_quote = *p; |
| break; |
| default: |
| ensure_token (¤t_token); |
| g_string_append_c (current_token, *p); |
| break; |
| } |
| break; |
| |
| default: |
| /* Combines rules 4) and 6) - if we have a token, append to it, |
| * otherwise create a new token. |
| */ |
| ensure_token (¤t_token); |
| g_string_append_c (current_token, *p); |
| break; |
| } |
| } |
| |
| /* We need to count consecutive backslashes mod 2, |
| * to detect escaped doublequotes. |
| */ |
| if (*p != '\\') |
| quoted = FALSE; |
| else |
| quoted = !quoted; |
| |
| ++p; |
| } |
| |
| delimit_token (¤t_token, &retval); |
| |
| if (current_quote) |
| { |
| if (current_quote == '\\') |
| g_set_error (error, |
| G_SHELL_ERROR, |
| G_SHELL_ERROR_BAD_QUOTING, |
| _("Text ended just after a '\\' character." |
| " (The text was '%s')"), |
| command_line); |
| else |
| g_set_error (error, |
| G_SHELL_ERROR, |
| G_SHELL_ERROR_BAD_QUOTING, |
| _("Text ended before matching quote was found for %c." |
| " (The text was '%s')"), |
| current_quote, command_line); |
| |
| goto error; |
| } |
| |
| if (retval == NULL) |
| { |
| g_set_error_literal (error, |
| G_SHELL_ERROR, |
| G_SHELL_ERROR_EMPTY_STRING, |
| _("Text was empty (or contained only whitespace)")); |
| |
| goto error; |
| } |
| |
| /* we appended backward */ |
| retval = g_slist_reverse (retval); |
| |
| return retval; |
| |
| error: |
| g_assert (error == NULL || *error != NULL); |
| |
| g_slist_free_full (retval, g_free); |
| |
| return NULL; |
| } |
| |
| /** |
| * g_shell_parse_argv: |
| * @command_line: command line to parse |
| * @argcp: (out) (optional): return location for number of args |
| * @argvp: (out) (optional) (array length=argcp zero-terminated=1): return |
| * location for array of args |
| * @error: (optional): return location for error |
| * |
| * 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. Possible errors are those from the #G_SHELL_ERROR |
| * domain. Free the returned vector with g_strfreev(). |
| * |
| * Returns: %TRUE on success, %FALSE if error set |
| **/ |
| gboolean |
| g_shell_parse_argv (const gchar *command_line, |
| gint *argcp, |
| gchar ***argvp, |
| GError **error) |
| { |
| /* Code based on poptParseArgvString() from libpopt */ |
| gint argc = 0; |
| gchar **argv = NULL; |
| GSList *tokens = NULL; |
| gint i; |
| GSList *tmp_list; |
| |
| g_return_val_if_fail (command_line != NULL, FALSE); |
| |
| tokens = tokenize_command_line (command_line, error); |
| if (tokens == NULL) |
| 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 = g_slist_length (tokens); |
| argv = g_new0 (gchar*, argc + 1); |
| i = 0; |
| tmp_list = tokens; |
| while (tmp_list) |
| { |
| argv[i] = g_shell_unquote (tmp_list->data, error); |
| |
| /* Since we already checked that quotes matched up in the |
| * tokenizer, this shouldn't be possible to reach I guess. |
| */ |
| if (argv[i] == NULL) |
| goto failed; |
| |
| tmp_list = g_slist_next (tmp_list); |
| ++i; |
| } |
| |
| g_slist_free_full (tokens, g_free); |
| |
| if (argcp) |
| *argcp = argc; |
| |
| if (argvp) |
| *argvp = argv; |
| else |
| g_strfreev (argv); |
| |
| return TRUE; |
| |
| failed: |
| |
| g_assert (error == NULL || *error != NULL); |
| g_strfreev (argv); |
| g_slist_free_full (tokens, g_free); |
| |
| return FALSE; |
| } |
