Data piped to 'mapfile', 'readarray', 'read -a' shell builtins is ignored

2010-03-24 Thread Rob Robason 
Configuration: 
OS: Fedora 11 - with all updates applied
Bash: version 4.0.23(1)-release

Problem description:
When stdin is a pipeline to 'mapfile', 'readarray', and 'read -a' shell
built-in commands, they fail to assign any values to the target array.
The array is neither unset nor altered in any way. No error message is
produced, and $? == 0.
None of the available options have any effect on this behavior. 
Oddly, when input is provided via keyboard or redirection (<), these
commands function properly. This last point seems really weird to me and
points to the built-ins' or shell's internal handling of a pipeline.

mapfile/readarray example (mapfile behaves identically to readarray):
$ ls -a | readarray# using the default MAPFILE array
$ echo $?
0
$ echo "${#mapfi...@]}"
0
$

Other forms of mapfile/readarray that fail:
$ ls -a | readarray -u0# specified input file descriptor
$ echo "${#mapfi...@]}"
0
$

$ declare -a myArray   # (optional) Declaring myArray has no
effect 
$ ls -a | readarray myArray
$ echo "${#myarr...@]}"
0
$

read -a example:
$ ls -a | read -a myArray
$ echo "${#myarr...@]}"
0
$ 

The other ways of using stdin (i.e. keyboard, file redirection) work
fine. For example:

mapfile/readarray keyboard:
$ readarray myArray# input from keyboard
1
line 2
3
[cntl-D]
$ echo "${#myarr...@]}"
3
$ 

mapfile/readarray redirection:
$ ls -a > foo
$ readarray myArray < foo
$ echo "${#myarr...@]}"
6
$ 

read -a redirection: 

$ ls -a > foo
$ read -a myArray < foo
$ echo "${#myarr...@]}"
1
$ 

Rob Robason
r...@robason.net
925-825-1512

printf builtin: '*' broken in conversion spec field width and precision (e.g., "%.*s")

2010-03-25 Thread Rob Robason 
Sorry I couldn't use bugbash - I don't work with source.

I've attached a complete description of the bug.

Regards,

Rob Robason
Driving Breakthrough Performance in Software Product Quality and
Development Practices

   Phone: 
925-825-1512
Home: 
Concord, CA 94518
  Mobile: 
925-348-1512
 Website: 
http://rob.robason.net
   Email: 
r...@robason.net

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printf: '*' broken in conversion spec field width and precision (e.g., "%.*s")

GNU bash, version 4.0.23(1)-release (i386-redhat-linux-gnu) on Fedora 11
(additional configuration info appears at the bottom of the page)


The printf builtin is broken in many variations of use of '*' (e.g., "%.*s") 
in a printf conversion spec to set field width and precision from argument 
values.

The following (bash builtin) command returns an empty line. E.g.:
  $ printf "%.*s\n" 5 "Sample string"

  $

Compare to correct behavior of printf(1) (/usr/bin/printf) with same args
  $ /usr/bin/printf "%.*s\n" 5 "Sample string"
  Sampl
  $

The builtin works only with either "*.*" or "m.m", (where m is an int), but 
not with any of the following legal usages: ".*", "*.", "m.*", "*.m", which 
are all legal variations. I haven't checked the positional "*m$" variants. 
Although I encountered this working with strings, the same problem exists for 
specifiers other than 's'. See "Other examples", below.

The builtin should work as defined for printf(1) and printf(3) (plus of course 
its own added features defined in bash(1)). 

Defined Behavior (man pages, printf(3) gives the most complete picture):
bash(1):
  [in section SHELL BUILTIN COMMANDS, printf]
"printf [-v var] format [arguments]"
"The format is a character string which contains ... format specifications, 
  each of which causes printing of the next successive argument. In 
  addition to the standard printf(1) formats, ..." 
[no relevant format specifier detail provided]
printf(1): 
  "Interpreted sequences are: ...
  "and all C format specifications ending with one of diouxXfeEgGcs, ... 
  "Variable widths are handled."
  
printf(3):
  [in section "Format of the format string""]
"Each conversion specification is introduced by the character %, and 
  ends with a conversion specifier. In between there may be (in this order) 
  zero or more flags, an _optional_ minimum field width, an _optional_ 
  precision and an optional length modifier."
  [in section "The precision"]:
"An optional precision, in the form of a period ('.') followed by an 
  optional decimal digit string. 
"Instead of a decimal digit string one may write "*" or "*m$" (for some 
  decimal integer m) to specify that the precision is given in the next 
  argument, or in the m-th argument, ...
"This gives the ... the maximum number of characters to be printed from 
  a string for s and S conversions.
  [in section "The conversion specifier, s"]:
"If a precision is specified, no more bytes than the number specified are 
  written, ...

Other examples:
  Other specifiers (f shown here) seem to share the bug:
  $ printf "%*.*f\n" 8 2 123.4567890 # "*.*" OK
123.46
  $ printf "%8.*f\n" 2 123.4567890   # "m.*" Broken
   123


Configuration info:
running Fedora 11 with all available updates installed

$ bash --version
GNU bash, version 4.0.23(1)-release (i386-redhat-linux-gnu)

$ uname -a
Linux [hostname masked for privacy].net 2.6.30.10-105.2.23.fc11.i686.PAE #1 SMP 
Thu Feb 11 07:05:37 UTC 2010 i686 athlon i386 GNU/Linux

$ sudo lshw
[hostname masked for privacy].net
description: Desktop Computer
product: GA-MA78GM-US2H
vendor: Gigabyte Technology Co., Ltd.
width: 32 bits
capabilities: smbios-2.4 dmi-2.4 smp-1.4 smp
configuration: boot=normal chassis=desktop cpus=2 uuid=30303234-[masked for 
privacy]
  *-core
   description: Motherboard
   product: GA-MA78GM-US2H
   vendor: Gigabyte Technology Co., Ltd.
   physical id: 0
   version: x.x
 *-firmware
  description: BIOS
  vendor: Award Software International, Inc.
  physical id: 0
  version: F3 (03/11/2009)
  size: 128KiB
  capacity: 960KiB
  capabilities: isa pci pnp apm upgrade shadowing cdboot bootselect 
socketedrom edd int13floppy360 int13floppy1200 int13floppy720 int13floppy2880 
int5printscreen int9keyboard int14serial int17printer int10video acpi usb agp 
ls120boot zipboot biosbootspecification
 *-cpu:0
  description: CPU
  product: AMD Athlon(tm) 7750 Dual-Core Processor
  vendor: Advanced Micro Devices [AMD]
  physical id: 4
  bus info: c...@0
  version: 15.2.3
  slot: Socket M2
  size: 1350MHz
  capacity: 3GHz
  width: 64 bits
  clock: 200MHz
... [more output available if needed]