ritter@cs.msstate.edu (Thomas H. Ritter) (08/15/89)
In a recent article: > From: Tricia Gardenhire <tgardenh@nmsu.edu> > Subject: Summarize: killing with awk and grep > > more about how grep, and awk work now. Any way, to summarize, the > easiest way to do this was: > > kill `ps -aux | fgrep -e -sleeper | egrep -v fgrep | awk '{print $2}'` > > Most other ideas were similar, but were more involved shell scripts. I agree that this is an easy and convient solution, but one thing struck me as I read people's postings to your question. All the solutions I saw used awk to get the second column of the ps listing. Why use such a general purpose tool for so simple a task? SystemV provides the cut command. eg. kill `ps -aux | fgrep -e -sleeper | egrep -v fgrep | cut -d" " -f5` This solution uses a program that is considerably cheaper in overhead than awk. (awk is an interpreted language) I know that some 4.XBSD systems don't provide cut. But, I think if a nice tool is available use it. (portablilty aside) Tom Ritter ritter@cs.msstate.edu
abcscnge@csuna.csun.edu (Scott "The Pseudo-Hacker" Neugroschl) (08/23/89)
In article <20608@adm.BRL.MIL> ritter@cs.msstate.edu (Thomas H. Ritter) writes:
]In a recent article:
]All the solutions I saw used awk to get the second column of the
]ps listing. Why use such a general purpose tool for so simple
]a task? SystemV provides the cut command. eg.
]
]kill `ps -aux | fgrep -e -sleeper | egrep -v fgrep | cut -d" " -f5`
The problem with cut is that if you specify the delimiter with -d, then
consecutive delimiters will return empty strings: e.g.
a<blank><blank>b
where <blank> is a single blank:
cut -d" " -f2 returns an empty string, and cut -d" " -f3 returns the b
Scott
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Scott "The Pseudo-Hacker" Neugroschl
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