What were you trying to do that didn't work?

If "filename" is generated by process substitution, the Korn shell introduces a space before the generated pathname which breaks the command syntax.

====

$ bash -cx 'echo @<(date)'
+ echo @/dev/fd/63
@/dev/fd/63

$ ksh -cx 'echo @<(date)'
+ echo @ /dev/fd/3
@ /dev/fd/3         .>>
====

The Korn shell has split the "@filename" into two arguments which means a real command (other than the demonstration "echo" command) fails as the arguments are now invalid.

Facing this while attempting to use process substitution with a leading @ character (e.g., @<(date). According to the ksh man page observed that , process substitution <(list) or >(list) should expand into a single filename argument. Instead, seems ksh splits this into two arguments (@ and /dev/fd/...).

What is the impact of this issue to you?

Customer reported that Re-coding required to avoid Korn shell in this scenario.

Please provide the package NVR for which the bug is seen:

In customer's environment:

$ rpm -qf /bin/ksh
ksh-1.0.6-4.el9_5.x86_64

In my test system where issue is reproducible as well:

1. rpm -q ksh
   ksh-1.0.6-7.el9_6.1.x86_64

   How reproducible is this bug?:

Always

Steps to reproduce:

1. Install ksh on a RHEL system.

1. Run a simple process substitution in ksh with a leading `@`. 

 $ ksh -cx 'echo @<(date)'
   + date
   + echo @ /dev/fd/3
   @ /dev/fd/3   

Expected results:

       The substitution should remain a single token:

# ksh -cx 'echo @<(date)'
+ echo @/dev/fd/3 
@/dev/fd/3

Actual results:

      ksh splits the expansion into two tokens:

+ echo @ /dev/fd/3
@ /dev/fd/3