[net.unix-wizards] Why does 4.2 ps put commands in parentheses?

mcb@tisstyx (Michael C. Berch) (02/28/85)

This puzzled me for a while, too. A command name in parentheses
means that ps couln't find the arguments on the stack, and the
output is the one used if you type "ps -c". Why does this occur?

If you have an exceptionally lengthy vector of environment
strings, they will push the argument list pointer out of the
range where ps expects it to be. Ps looks, decides that it can;t
find the args, and gives up and does a "ps -c", with the command
name (from the acct structure, I think -- though I haven't
looked) in parentheses.

So people with exceptionally verbose environments might have this
happen to them. It happened to me when I installed a new
terminal, changed my TERMCAP (it was still getting set during
.login), and suddenly this mystery began.

The easy solution is to shorten your environment; the hard
solution is to hack ps and get it to be more energetic about
looking for the arg list.

mcb@tisstyx (Michael C. Berch) (02/28/85)

This puzzled me for a while, too. A command name in parentheses
means that ps couln't find the arguments on the stack, and the
output is the one used if you type "ps -c". Why does this occur?

If you have an exceptionally lengthy vector of environment
strings, they will push the argument list pointer out of the
range where ps expects it to be. Ps looks, decides that it can;t
find the args, and gives up and does a "ps -c", with the command
name (from the acct structure, I think -- though I haven't
looked) in parentheses.

So people with exceptionally verbose environments might have this
happen to them. It happened to me when I installed a new
terminal, changed my TERMCAP (it was still getting set during
.login), and suddenly this mystery began.

The easy solution is to shorten your environment; the hard
solution is to hack ps and get it to be more energetic about
looking for the arg list.

--
Michael C. Berch
Control Data Corp./Lawrence Livermore Natl. Laboratory
mcb@lll-tis.ARPA
{akgua,allegra,cbosgd,decwrl,dual,ihnp4,sun}!idi!styx!mcb
                                         ...!idi!lll-tis!mcb

ron@BRL-TGR (Ron Natalie) (02/28/85)

The other thing is that people can obliterate the part of the stack
that has the arguments on it.

-Ron