The following issue has been SUBMITTED.
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http://austingroupbugs.net/view.php?id=1199
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Reported By: bhaible
Assigned To:
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Project: 1003.1(2016)/Issue7+TC2
Issue ID: 1199
Category: System Interfaces
Type: Error
Severity: Editorial
Priority: normal
Status: New
Name: Bruno Haible
Organization: GNU
User Reference:
Section: strfmon
Page Number: 2039 to 2043
Line Number: 65327 to 65492
Interp Status: ---
Final Accepted Text:
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Date Submitted: 2018-08-12 19:23 UTC
Last Modified: 2018-08-12 19:23 UTC
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Summary: strfmon, if standards compliant, produces highly
misleading results
Description:
The following program shows strfmon results in the C locale:
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#include <locale.h>
#include <monetary.h>
#include <stdio.h>
int main ()
{
char buf[80];
printf ("currency = |%s|\n", localeconv()->currency_symbol);
printf ("positive sign = |%s|\n", localeconv()->positive_sign);
printf ("negative sign = |%s|\n", localeconv()->negative_sign);
strfmon (buf, sizeof (buf), "%^#5.0n", 123.4);
printf ("strfmon result for positive value = |%s|\n", buf);
strfmon (buf, sizeof (buf), "%^#5.0n", -123.4);
printf ("strfmon result for negative value = |%s|\n", buf);
strfmon (buf, sizeof (buf), "%.2n", 123.5);
printf ("strfmon result with 2 fractional digits: = |%s|\n", buf);
}
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The result on AIX 7.1 is:
currency = ||
positive sign = ||
negative sign = ||
strfmon result for positive value = | 123|
strfmon result for negative value = | 123|
strfmon result with 2 fractional digits: = |12350|
This is POSIX compliant, as far as I can see. However, without a
distinction between positive and negative values, and without a visible
decimal separator, this behaviour is useless, or even dangerous (if a
programmer was not aware of this behaviour and has not worked around it).
The result on glibc 2.23 is:
currency = ||
positive sign = ||
negative sign = ||
strfmon result for positive value = | 123|
strfmon result for negative value = |- 123|
strfmon result with 2 fractional digits: = |123.50|
This is not POSIX compliant, because in the negative value case, it shows a
'-' sign, although localeconv()->negative_sign is the empty string (which
is mandated by POSIX
http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap07.html#tag_07_03_03_01
).
The result on Solaris 10 is:
currency = ||
positive sign = ||
negative sign = ||
strfmon result for positive value = | 123|
strfmon result for negative value = |- 123|
strfmon result with 2 fractional digits: = |123.50|
This is not POSIX compliant, 1. because of the '-' sign, 2. because it
produces
a different number of characters in the negative and in the positive case,
which is against what POSIX says for the '#' flag (lines 65387 to 65389):
To ensure alignment, any characters appearing before or after the
number in the formatted output such as currency or sign symbols are
padded as necessary with <space> characters to make their positive
and negative formats an equal length.
The result on macOS 10.13 is:
currency = ||
positive sign = ||
negative sign = ||
strfmon result for positive value = | 123 |
strfmon result for negative value = |( 123)|
strfmon result with 2 fractional digits: = |123.50|
This is not POSIX compliant, because the test program does not specify the
'+' nor '(' flag, and POSIX says (lines 65363 to 65366):
If '+' is specified, the locale's equivalent of '+' and '-' are
used (for example, in many locales, the empty string if positive and '-'
if negative). If '(' is specified, negative amounts are enclosed within
parentheses. If neither flag is specified, the '+' style is used.
In summary, out of four implementations, only one is POSIX compliant, and
it produces highly misleading / dangerous results.
Desired Action:
Remove strfmon and strfmon_l from the standard. Also remove <monetary.h>
from the standard, since its only purpose is the declare these functions.
Or otherwise, change the standard so that the glibc results become the only
compliant results.
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Issue History
Date Modified Username Field Change
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2018-08-12 19:23 bhaible New Issue
2018-08-12 19:23 bhaible Name => Bruno Haible
2018-08-12 19:23 bhaible Organization => GNU
2018-08-12 19:23 bhaible Section => strfmon
2018-08-12 19:23 bhaible Page Number => 2039 to 2043
2018-08-12 19:23 bhaible Line Number => 65327 to 65492
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