dasdls writes on Linux to stdin, does 'write(0,....)'

[wfjm]

I use dasdls under Linux. First I saw that two lines of the dasdls output can't be redirected to a file, they always show up in the controlling terminal. Only with unbuffer(1) one gets the whole output redirected into a file. The lines are

  HHCDA004I opening mvsres.148 readonly
  HHCDA020I mvsres.148 cyls=560 heads=30 tracks=16800 trklen=19456

Running dasdls under strace(1) gives

  write(2, "Hercules DASD list program Versi"..., 
  write(2, "(c)Copyright 1999-2015 by Roger "..., 
  write(0, "HHCDA004I opening mvsres.148 rea"..., 
  write(0, "HHCDA020I mvsres.148 cyls=560 he"...,
  write(1, "mvsres.148: VOLSER=MVSRES\nZ99999"..., 

So there are writes to stdout and stderr, but also two writes to stdin. The issue can be reproduced with the current HEAD (commit 59f0556) and can be traced to

• ckddasd.c#L357-L359 --> logmsg (_("HHCDA004I opening...
• logmsg.c#L159-L160 --> log_write(0,bfr)
• logmsg.c#L247-L268 --> log_write(int panel,char *msg)

The logic of log_write finally poduces somehow a write(0,...) in the context of dasdls.

The dasdls coming with tk4- exhibits the same issue, while the dasdls from hercules-390/hyperion does no writes to stdin.

[Fish-Git]

... while the dasdls from hercules-390/hyperion does no writes to stdin.

FWIW, neither does SoftDevLabs's Fish-Git Hyperion either.