[CentOS] Extract lines from text file
Marcelo Beckmann
marcelo.beckmann at webers.com.br
Wed Aug 15 14:36:09 UTC 2012
Em 15-08-2012 11:22, Tony Molloy escreveu:
>
> Hi,
>
> I'm looking for a command to extract lines from a large text file, a
> password file. A typical user has a username made from a letter
> followed by their id-number.
>
> m9718508:pw:9301:840: Lynch :/home/pgstud/m9718508:/bin/bash
>
> So for instance if I need to extract lines where;
>
> the 1st field, the username begins with an m
> and
> the 4th field, the group contains exactly 850
>
> cat passwdfile | grep ^m | grep 850 > output
>
> is close but fails if the value 850 appears outside the 4th field. In
> the above example which should be ignored 850 appears in the username
> and home directory and is therefore extracted.
>
> Any ideas.
]$ cat testcentoslist
m9718508:pw:9301:840: Lynch :/home/pgstud/m9718508:/bin/bash
m9718308:pw:9301:850: Lynch :/home/pgstud/m9718508:/bin/bash
m9718208:pw:9301:840: Lynch :/home/pgstud/m9718508:/bin/bash
m9718508:pw:9301:840: Lynch :/home/pgstud/m9718908:/bin/bash
]$ cat testcentoslist | egrep ^m.*:.*:.*:850:
m9718308:pw:9301:850: Lynch :/home/pgstud/m9718508:/bin/bash
--
Marcelo Beckmann
Suporte Corporativo - suporte at webers.com.br
Webers Tecnologia - http://www.webers.com.br
Curitiba (PR) (41) 3094-6600
Rio de Janeiro (RJ) (21) 4007-1207
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