ksh93 on AIX not treating leading-zero constants as octal when OCTAL_CONST=ON

[ravindra-shinde2]

I’m running into an issue with numeric constants in ksh93 on AIX

$ ksh93 --version
version sh (AT&T Research) 93u+m/1.0.10 2024-08-01

export OCTAL_CONST=ON

val1=$((015))
if [ $val1 -eq 13 ]
then
echo "pass"
else
echo "fail"
fi

val2=$((045))
if [ $val2 -eq 37 ]
then
echo "pass"
else
echo "fail"
fi

Expected behavior:
015 should be treated as octal → decimal 13.
045 should be treated as octal → decimal 37.

Actual behavior:
val1=$((015))
echo $val1 # prints 15 (decimal)

val2=$((045))
echo $val2 # prints 45 (decimal)

Question:
Is this a bug in AIX’s ksh93 build, or is there a new expected behavior around OCTAL_CONST?
How should we correctly enable octal interpretation of leading-zero constants in modern ksh93?

[phidebian]

May be you meant

TC$ set -o letoctal                                                 
TC$ let val1=015 ; echo $val1
13

[ravindra-shinde2]

Apologies for the confusion in my earlier message — the macro I mentioned (OCTAL_CONST) is redundant.
I was testing an arithmetic expression:

val1=$((015)); echo $val1
and noticed different results across ksh93 versions.

`$ ksh93 --version
version sh (AT&T Research) 93u+ 2012-08-01

$ val1=$((015)); echo $val1
13
$ ksh93 --version
version sh (AT&T Research) 93u+m/1.0.10 2024-08-01

$ val1=$((015)); echo $val1
15`

It looks like one version is treating 015 as octal, while the other interprets it as decimal.
Is letoctal being set by default in some builds of ksh93? Could this behavior be related to letoctal?

[phidebian]

May be posix mode was on on some of yours systems

TC$ val1=$((015)); echo $val1                                       
15

TC$ set -o posix  

TC$ val1=$((015)); echo $val1
13

[ravindra-shinde2]

On ksh93 (93u+ 2012-08-01), it seems that POSIX mode is enabled by default, but it does not appear in the set -o output.

$ ksh93 --version
version sh (AT&T Research) 93u+m/1.0.10 2024-08-01

$ set -o | grep posix
posix                    off

$ ksh93 --version
  version         sh (AT&T Research) 93u+ 2012-08-01

$ set -o | grep posix
# (no output)

Is this the expected behavior, or should posix be listed in the set -o output?

[posguy99]

The posix option is a u+m addition to ksh93, it is not in the AT&T release.

From NEWS:

2020-09-01:

• A long-form shell option '-o posix' has been added, which implements a
  mode for better compatibility with the POSIX standard. It is automatically
  turned on if ksh is invoked under the name 'sh'.
  For now, it:
  • disables the &> redirection shorthand
  • causes the 'let' arithmetic command to recognise octal numbers by
    leading zeros regardless of the setting of the 'letoctal' option
  • causes file descriptors > 2 to be left open when invoking another program
  • makes the <> redirection operator default to stdin instead of stdout
    (this keeps the 2020-05-13 BUG_REDIRIO fix for the POSIX mode while
    restoring traditional ksh93 behaviour for backwards compatibility)
  • disables a noncompliant 'test -t' == 'test -t 1' compatibility hack
  • disables passing an exported variable's attributes (such as integer or
    readonly) to a new ksh process through the environment