Re: [Bug-gnulib] addition: sh-quote.c

[Paul Eggert]

Bruno Haible <address@hidden> writes:

> The fit is indeed very close. Only four things prevent me from using quotearg
> with shell_quoting_style:

Thanks for your comments.  I hope the following draft patch addresses
them all; if so, I'll install it.

2004-02-04  Paul Eggert  <address@hidden>

        * quotearg.h (quotearg_alloc): New decl.
        * quotearg.c (quotearg_alloc): New function.
        (quotearg_buffer_restyled): Treat lone { and } as special.
        Treat = as special.  Work around bug with older shells
        that "see" a '\' that is really the 2nd byte of a multibyte char.
        Quote empty string with shell_quoting_style.
        All of this is due to suggestions by Bruno Haible.

Index: lib/quotearg.h
===================================================================
RCS file: /cvsroot/gnulib/gnulib/lib/quotearg.h,v
retrieving revision 1.9
diff -p -u -r1.9 quotearg.h
--- lib/quotearg.h      23 Nov 2002 06:45:22 -0000      1.9
+++ lib/quotearg.h      4 Feb 2004 22:50:20 -0000
@@ -1,6 +1,6 @@
 /* quotearg.h - quote arguments for output
 
-   Copyright (C) 1998, 1999, 2000, 2001, 2002 Free Software
+   Copyright (C) 1998, 1999, 2000, 2001, 2002, 2004 Free Software
    Foundation, Inc.
 
    This program is free software; you can redistribute it and/or modify
@@ -80,6 +80,11 @@ int set_char_quoting (struct quoting_opt
 size_t quotearg_buffer (char *buffer, size_t buffersize,
                        char const *arg, size_t argsize,
                        struct quoting_options const *o);
+
+/* Like quotearg_buffer, except return the result in a newly allocated
+   buffer.  It is the caller's responsibility to free the result.  */
+char *quotearg_alloc (char const *arg, size_t argsize,
+                     struct quoting_options const *o);
 
 /* Use storage slot N to return a quoted version of the string ARG.
    Use the default quoting options.
Index: lib/quotearg.c
===================================================================
RCS file: /cvsroot/gnulib/gnulib/lib/quotearg.c,v
retrieving revision 1.40
diff -p -u -r1.40 quotearg.c
--- lib/quotearg.c      30 Oct 2003 06:33:40 -0000      1.40
+++ lib/quotearg.c      4 Feb 2004 22:50:20 -0000
@@ -1,5 +1,7 @@
 /* quotearg.c - quote arguments for output
-   Copyright (C) 1998, 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
+
+   Copyright (C) 1998, 1999, 2000, 2001, 2002, 2004 Free Software
+   Foundation, Inc.
 
    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
@@ -174,7 +176,7 @@ gettext_quote (char const *msgid, enum q
    size of the output, not counting the terminating null.
    If BUFFERSIZE is too small to store the output string, return the
    value that would have been returned had BUFFERSIZE been large enough.
-   If ARGSIZE is -1, use the string length of the argument for ARGSIZE.
+   If ARGSIZE is SIZE_MAX, use the string length of the argument for ARGSIZE.
 
    This function acts like quotearg_buffer (BUFFER, BUFFERSIZE, ARG,
    ARGSIZE, O), except it uses QUOTING_STYLE instead of the quoting
@@ -326,6 +328,10 @@ quotearg_buffer_restyled (char *buffer, 
            }
          break;
 
+       case '{': case '}': /* sometimes special if isolated */
+         if (! (argsize == SIZE_MAX ? arg[1] == '\0' : argsize == 1))
+           break;
+         /* Fall through.  */
        case '#': case '~':
          if (i != 0)
            break;
@@ -334,7 +340,9 @@ quotearg_buffer_restyled (char *buffer, 
        case '!': /* special in bash */
        case '"': case '$': case '&':
        case '(': case ')': case '*': case ';':
-       case '<': case '>': case '[':
+       case '<':
+       case '=': /* sometimes special in 0th or (with "set -k") later args */
+       case '>': case '[':
        case '^': /* special in old /bin/sh, e.g. SunOS 4.1.4 */
        case '`': case '|':
          /* A shell special character.  In theory, '$' and '`' could
@@ -364,7 +372,7 @@ quotearg_buffer_restyled (char *buffer, 
 
        case '%': case '+': case ',': case '-': case '.': case '/':
        case '0': case '1': case '2': case '3': case '4': case '5':
-       case '6': case '7': case '8': case '9': case ':': case '=':
+       case '6': case '7': case '8': case '9': case ':':
        case 'A': case 'B': case 'C': case 'D': case 'E': case 'F':
        case 'G': case 'H': case 'I': case 'J': case 'K': case 'L':
        case 'M': case 'N': case 'O': case 'P': case 'Q': case 'R':
@@ -374,7 +382,6 @@ quotearg_buffer_restyled (char *buffer, 
        case 'i': case 'j': case 'k': case 'l': case 'm': case 'n':
        case 'o': case 'p': case 'q': case 'r': case 's': case 't':
        case 'u': case 'v': case 'w': case 'x': case 'y': case 'z':
-       case '{': case '}':
          /* These characters don't cause problems, no matter what the
             quoting style is.  They cannot start multibyte sequences.  */
          break;
@@ -427,6 +434,22 @@ quotearg_buffer_restyled (char *buffer, 
                      }
                    else
                      {
+                       /* Work around a bug with older shells that "see" a '\'
+                          that is really the 2nd byte of a multibyte character.
+                          In practice the problem is limited to ASCII
+                          chars >= '@' that are shell special chars.  */
+                       if ('[' == 0x5b && quoting_style == shell_quoting_style)
+                         {
+                           size_t j;
+                           for (j = 1; j < bytes; j++)
+                             switch (arg[i + m + j])
+                               {
+                               case '[': case '\\': case '^':
+                               case '`': case '|':
+                                 goto use_shell_always_quoting_style;
+                               }
+                         }
+                           
                        if (! iswprint (w))
                          printable = 0;
                        m += bytes;
@@ -472,6 +495,9 @@ quotearg_buffer_restyled (char *buffer, 
       STORE (c);
     }
 
+  if (i == 0 && quoting_style == shell_quoting_style)
+    goto use_shell_always_quoting_style;
+
   if (quote_string)
     for (; *quote_string; quote_string++)
       STORE (*quote_string);
@@ -492,7 +518,8 @@ quotearg_buffer_restyled (char *buffer, 
    size of the output, not counting the terminating null.
    If BUFFERSIZE is too small to store the output string, return the
    value that would have been returned had BUFFERSIZE been large enough.
-   If ARGSIZE is -1, use the string length of the argument for ARGSIZE.  */
+   If ARGSIZE is SIZE_MAX, use the string length of the argument for
+   ARGSIZE.  */
 size_t
 quotearg_buffer (char *buffer, size_t buffersize,
                 char const *arg, size_t argsize,
@@ -506,8 +533,23 @@ quotearg_buffer (char *buffer, size_t bu
   return r;
 }
 
+/* Like quotearg_buffer (..., ARG, ARGSIZE, O), except return newly
+   allocated storage containing the quoted string.  */
+char *
+quotearg_alloc (char const *arg, size_t argsize,
+               struct quoting_options const *o)
+{
+  int e = errno;
+  size_t bufsize = quotearg_buffer (0, 0, arg, argsize, o) + 1;
+  char *buf = xmalloc (bufsize);
+  quotearg_buffer (buf, bufsize, arg, argsize, o);
+  errno = e;
+  return buf;
+}
+
 /* Use storage slot N to return a quoted version of argument ARG.
-   ARG is of size ARGSIZE, but if that is -1, ARG is a null-terminated string.
+   ARG is of size ARGSIZE, but if that is SIZE_MAX, ARG is a
+   null-terminated string.
    OPTIONS specifies the quoting options.
    The returned value points to static storage that can be
    reused by the next call to this function with the same value of N.