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
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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]
