Austin Group Defect Tracker

Aardvark Mark IV


Viewing Issue Simple Details Jump to Notes ] Issue History ] Print ]
ID Category Severity Type Date Submitted Last Update
0000322 [1003.1(2004)/Issue 6] Shell and Utilities Objection Omission 2010-09-18 18:01 2010-09-18 18:20
Reporter Don Cragun View Status public  
Assigned To ajosey
Priority normal Resolution Rejected  
Status Closed  
Name Nick Stoughton
Organization USENIX
User Reference nms-hex-string
Section printf
Page Number 743
Line Number 28941-28944
Interp Status ---
Final Accepted Text
Summary 0000322: Defect in XCU File Format Notation
Description The printf utility in XCU and the printf library interface in XSH (and C99) have great similarity, but are not completely aligned.

In particular, C99 allows additional escape sequences in the format string (which in C99 is just an array of characters).

C99 defines a character constant as including an escape sequence:
    escape-sequence:
        simple-escape-sequence
        octal-escape-sequence
        hexadecimal-escape-sequence
        universal-character-name


The file format notation (used by the printf utility) has the first two of these (the simple escape sequence is slightly different, though not in a way that is detectable, in that it does not explicitly require \' \" and \? processing, but the shell for

The file format notation does not require hexadecimal or universal character names.

Hexadecimal escapes in particular are commonly implemented as extensions (e.g. coreutils), and frequently used when patching binary files. Indeed, coreutils also implements universal-character-names.
Desired Action (draft 3.4 page XCU 3038 line 100761)
change:
In addition to the escape sequences shown in XBD Chapter 5 (on page 119)
(\\, \a, \b, \f, \n, \r, \t, \v),
"\ddd", where ddd is a one, two, or three-digit
octal number, shall be written as a byte with the numeric value
specified by the octal number.

to

In addition to the escape sequences shown in XBD Chapter 5 (on page 119)
(\\, \a, \b, \f, \n, \r, \t, \v),
the following escape sequences shall also be recognized:
   + "\ddd", where ddd is a one, two, or three-digit
   octal number, shall be written as a byte with the numeric value
   specified by the octal number.
   + "\xdd", where dd is a one or two digit hexadecimal number, shall
   be written as a byte with the numeric value specified by the
   hexadecimal number.
   + "\udddd", where dddd is a four character hexadecimal number,
   shall be written as the character whose four-digit short identifier
   as specified by ISO/IEC 10646) is dddd, except that a character
   whose short identifier is less than 00A0 other than 0024 ($),
   0040 (@), or 0060 (), or one in the range D800 through
   DFFF inclusive need not be supported.
   + "\Udddddddd", where dddddddd is an eight character hexadecimal
   number shall be written as the character whose eight-digit short
   identifier as specified by ISO/IEC 10646) is dddddddd,
   except that a character whose short identifier is less than
   000000A0 other than 00000024 ($),
   00000040 (@), or 00000060 (), or one in the range 0000D800
   through 0000DFFF inclusive need not be supported.

NOTE: The disallowed characters are the characters in the basic character set and the code positions
 reserved
by ISO/IEC 10646 for control characters, the character
DELETE, and the S-zone (reserved for use by
UTF−16)

=======
Before line 100778 (d3.4), insert the following:
   + "\xdd" where dd is a one, or two digit hexadecimal number that
    shall be converted to a byte with the numeric value
    specified by the hexadecimal number
Tags No tags attached.
Attached Files

- Relationships
related to 0000249Under Reviewajosey 1003.1(2008)/Issue 7 Add standard support for $'...' in shell 

-  Notes
(0000556)
Don Cragun (manager)
2010-09-18 18:08

This item was sent down the interpretations track as AI-211, but
encountered significant objections. Hence this item has been rejected.

The former disposition of the bug is enclosed here:

ERN 177(->interps track) AI-211
Send down the interps track, the std is silent on the issue

Take the changes in the Desired Action and then also update the section
of APP USAGE to

 line 100839 in d3.4 top of page 3040

The treatment of hexadecimal escapes in the format operand differs from
the way hexadecimal character constants are recognized in a C string
literal used as the format argument for the printf() family of functions.
In the printf utility they are limited to two hexadecimal digits because
otherwise there would be no consistent way to detect the end of the
constant. In C string literals, hexadecimal escape sequences are only
terminated by a non-hex-digit character or the end of the string literal;
concatenation of adjacent string literals can be used to terminate an
escape sequence and follow it with a hexadecimal character to be written.
In the shell, concatenation occurs before the printf utility has a chance
to parse the end of the hexadecimal constant.
(0000557)
Don Cragun (manager)
2010-09-18 18:20
edited on: 2010-09-20 22:08

As noted in Note: 0000556 an attempt to approve the
proposed resolution as an interpretation encountered significant objections.
The discussion concerning this proposal can be found in austin-group-l e-mail
sequence numbers: 11363, 11373-11374, 11502, 11509-11510, 11512-11514,
11516, and 11519-11528.

See 0000249 for a request to add $'...' to the shell as proposed by some in the
above discussion.


- Issue History
Date Modified Username Field Change
2010-09-18 18:01 Don Cragun New Issue
2010-09-18 18:01 Don Cragun Status New => Under Review
2010-09-18 18:01 Don Cragun Assigned To => ajosey
2010-09-18 18:01 Don Cragun Name => Nick Stoughton
2010-09-18 18:01 Don Cragun Organization => USENIX
2010-09-18 18:01 Don Cragun User Reference => nms-hex-string
2010-09-18 18:01 Don Cragun Section => printf
2010-09-18 18:01 Don Cragun Page Number => 743
2010-09-18 18:01 Don Cragun Line Number => 28941-28944
2010-09-18 18:01 Don Cragun Interp Status => ---
2010-09-18 18:08 Don Cragun Note Added: 0000556
2010-09-18 18:08 Don Cragun Resolution Open => Rejected
2010-09-18 18:08 Don Cragun Desired Action Updated
2010-09-18 18:12 Don Cragun Relationship added related to 0000249
2010-09-18 18:20 Don Cragun Note Added: 0000557
2010-09-18 18:20 Don Cragun Status Under Review => Closed
2010-09-20 22:08 Don Cragun Note Edited: 0000557


Mantis 1.1.6[^]
Copyright © 2000 - 2008 Mantis Group
Powered by Mantis Bugtracker