+
−/* Quoting for a system command.
+
−   Copyright (C) 2012-2013 Free Software Foundation, Inc.
+
−   Written by Bruno Haible <bruno@clisp.org>, 2012.
+
−
+
−   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 3 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, see <http://www.gnu.org/licenses/>.  */
+
−
+
−#include <config.h>
+
−
+
−/* Specification.  */
+
−#include "system-quote.h"
+
−
+
−#include <stdbool.h>
+
−#include <stdlib.h>
+
−#include <string.h>
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−
+
−#include "sh-quote.h"
+
−#include "xalloc.h"
+
−
+
−#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+
−
+
−/* The native Windows CreateProcess() function interprets characters like
+
−   ' ', '\t', '\\', '"' (but not '<' and '>') in a special way:
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−   - Space and tab are interpreted as delimiters. They are not treated as
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−     delimiters if they are surrounded by double quotes: "...".
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−   - Unescaped double quotes are removed from the input. Their only effect is
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−     that within double quotes, space and tab are treated like normal
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−     characters.
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−   - Backslashes not followed by double quotes are not special.
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−   - But 2*n+1 backslashes followed by a double quote become
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−     n backslashes followed by a double quote (n >= 0):
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−       \" -> "
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−       \\\" -> \"
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−       \\\\\" -> \\"
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−   - '*', '?' characters may get expanded through wildcard expansion in the
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−     callee: By default, in the callee, the initialization code before main()
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−     takes the result of GetCommandLine(), wildcard-expands it, and passes it
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−     to main(). The exceptions to this rule are:
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−       - programs that inspect GetCommandLine() and ignore argv,
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−       - mingw programs that have a global variable 'int _CRT_glob = 0;',
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−       - Cygwin programs, when invoked from a Cygwin program.
+
− */
+
−# define SHELL_SPECIAL_CHARS "\"\\ \001\002\003\004\005\006\007\010\011\012\013\014\015\016\017\020\021\022\023\024\025\026\027\030\031\032\033\034\035\036\037*?"
+
−# define SHELL_SPACE_CHARS " \001\002\003\004\005\006\007\010\011\012\013\014\015\016\017\020\021\022\023\024\025\026\027\030\031\032\033\034\035\036\037"
+
−
+
−/* Copies the quoted string to p and returns the number of bytes needed.
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−   If p is non-NULL, there must be room for system_quote_length (string)
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−   bytes at p.  */
+
−static size_t
+
−windows_createprocess_quote (char *p, const char *string)
+
−{
+
−  size_t len = strlen (string);
+
−  bool quote_around =
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−    (len == 0 || strpbrk (string, SHELL_SPECIAL_CHARS) != NULL);
+
−  size_t backslashes = 0;
+
−  size_t i = 0;
+
−# define STORE(c) \
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−  do                 \
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−    {                \
+
−      if (p != NULL) \
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−        p[i] = (c);  \
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−      i++;           \
+
−    }                \
+
−  while (0)
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−
+
−  if (quote_around)
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−    STORE ('"');
+
−  for (; len > 0; string++, len--)
+
−    {
+
−      char c = *string;
+
−
+
−      if (c == '"')
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−        {
+
−          size_t j;
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−
+
−          for (j = backslashes + 1; j > 0; j--)
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−            STORE ('\\');
+
−        }
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−      STORE (c);
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−      if (c == '\\')
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−        backslashes++;
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−      else
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−        backslashes = 0;
+
−    }
+
−  if (quote_around)
+
−    {
+
−      size_t j;
+
−
+
−      for (j = backslashes; j > 0; j--)
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−        STORE ('\\');
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−      STORE ('"');
+
−    }
+
−# undef STORE
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−  return i;
+
−}
+
−
+
−/* The native Windows cmd.exe command interpreter also interprets:
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−   - '\n', '\r' as a command terminator - no way to escape it,
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−   - '<', '>' as redirections,
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−   - '|' as pipe operator,
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−   - '%var%' as a reference to the environment variable VAR (uppercase),
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−     even inside quoted strings,
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−   - '&' '[' ']' '{' '}' '^' '=' ';' '!' '\'' '+' ',' '`' '~' for other
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−     purposes, according to
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−     <http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/cmd.mspx?mfr=true>
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−   We quote a string like '%var%' by putting the '%' characters outside of
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−   double-quotes and the rest of the string inside double-quotes: %"var"%.
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−   This is guaranteed to not be a reference to an environment variable.
+
− */
+
−# define CMD_SPECIAL_CHARS "\"\\ \001\002\003\004\005\006\007\010\011\012\013\014\015\016\017\020\021\022\023\024\025\026\027\030\031\032\033\034\035\036\037!%&'*+,;<=>?[]^`{|}~"
+
−# define CMD_FORBIDDEN_CHARS "\n\r"
+
−
+
−/* Copies the quoted string to p and returns the number of bytes needed.
+
−   If p is non-NULL, there must be room for system_quote_length (string)
+
−   bytes at p.  */
+
−static size_t
+
−windows_cmd_quote (char *p, const char *string)
+
−{
+
−  size_t len = strlen (string);
+
−  bool quote_around =
+
−    (len == 0 || strpbrk (string, CMD_SPECIAL_CHARS) != NULL);
+
−  size_t backslashes = 0;
+
−  size_t i = 0;
+
−# define STORE(c) \
+
−  do                 \
+
−    {                \
+
−      if (p != NULL) \
+
−        p[i] = (c);  \
+
−      i++;           \
+
−    }                \
+
−  while (0)
+
−
+
−  if (quote_around)
+
−    STORE ('"');
+
−  for (; len > 0; string++, len--)
+
−    {
+
−      char c = *string;
+
−
+
−      if (c == '"')
+
−        {
+
−          size_t j;
+
−
+
−          for (j = backslashes + 1; j > 0; j--)
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−            STORE ('\\');
+
−        }
+
−      if (c == '%')
+
−        {
+
−          size_t j;
+
−
+
−          for (j = backslashes; j > 0; j--)
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−            STORE ('\\');
+
−          STORE ('"');
+
−        }
+
−      STORE (c);
+
−      if (c == '%')
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−        STORE ('"');
+
−      if (c == '\\')
+
−        backslashes++;
+
−      else
+
−        backslashes = 0;
+
−    }
+
−  if (quote_around)
+
−    {
+
−      size_t j;
+
−
+
−      for (j = backslashes; j > 0; j--)
+
−        STORE ('\\');
+
−      STORE ('"');
+
−    }
+
−  return i;
+
−}
+
−
+
−#endif
+
−
+
−size_t
+
−system_quote_length (enum system_command_interpreter interpreter,
+
−                     const char *string)
+
−{
+
−  switch (interpreter)
+
−    {
+
−#if !((defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__)
+
−    case SCI_SYSTEM:
+
−#endif
+
−    case SCI_POSIX_SH:
+
−      return shell_quote_length (string);
+
−
+
−#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+
−    case SCI_WINDOWS_CREATEPROCESS:
+
−      return windows_createprocess_quote (NULL, string);
+
−
+
−    case SCI_SYSTEM:
+
−    case SCI_WINDOWS_CMD:
+
−      return windows_cmd_quote (NULL, string);
+
−#endif
+
−
+
−    default:
+
−      /* Invalid interpreter.  */
+
−      abort ();
+
−    }
+
−}
+
−
+
−char *
+
−system_quote_copy (char *p,
+
−                   enum system_command_interpreter interpreter,
+
−                   const char *string)
+
−{
+
−  switch (interpreter)
+
−    {
+
−#if !((defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__)
+
−    case SCI_SYSTEM:
+
−#endif
+
−    case SCI_POSIX_SH:
+
−      return shell_quote_copy (p, string);
+
−
+
−#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+
−    case SCI_WINDOWS_CREATEPROCESS:
+
−      p += windows_createprocess_quote (p, string);
+
−      *p = '\0';
+
−      return p;
+
−
+
−    case SCI_SYSTEM:
+
−    case SCI_WINDOWS_CMD:
+
−      p += windows_cmd_quote (p, string);
+
−      *p = '\0';
+
−      return p;
+
−#endif
+
−
+
−    default:
+
−      /* Invalid interpreter.  */
+
−      abort ();
+
−    }
+
−}
+
−
+
−char *
+
−system_quote (enum system_command_interpreter interpreter,
+
−              const char *string)
+
−{
+
−  switch (interpreter)
+
−    {
+
−#if !((defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__)
+
−    case SCI_SYSTEM:
+
−#endif
+
−    case SCI_POSIX_SH:
+
−      return shell_quote (string);
+
−
+
−#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+
−    case SCI_WINDOWS_CREATEPROCESS:
+
−    case SCI_SYSTEM:
+
−    case SCI_WINDOWS_CMD:
+
−      {
+
−        size_t length = system_quote_length (interpreter, string);
+
−        char *quoted = XNMALLOC (length, char);
+
−        system_quote_copy (quoted, interpreter, string);
+
−        return quoted;
+
−      }
+
−#endif
+
−
+
−    default:
+
−      /* Invalid interpreter.  */
+
−      abort ();
+
−    }
+
−}
+
−
+
−char *
+
−system_quote_argv (enum system_command_interpreter interpreter,
+
−                   char * const *argv)
+
−{
+
−  if (*argv != NULL)
+
−    {
+
−      char * const *argp;
+
−      size_t length;
+
−      char *command;
+
−      char *p;
+
−
+
−      length = 0;
+
−      for (argp = argv; ; )
+
−        {
+
−          length += system_quote_length (interpreter, *argp) + 1;
+
−          argp++;
+
−          if (*argp == NULL)
+
−            break;
+
−        }
+
−
+
−      command = XNMALLOC (length, char);
+
−
+
−      p = command;
+
−      for (argp = argv; ; )
+
−        {
+
−          p = system_quote_copy (p, interpreter, *argp);
+
−          argp++;
+
−          if (*argp == NULL)
+
−            break;
+
−          *p++ = ' ';
+
−        }
+
−      *p = '\0';
+
−
+
−      return command;
+
−    }
+
−  else
+
−    return xstrdup ("");
+
−}