[Courses][Linux comands] Finding things with locate, find, and grep

[Conor Daly]

On Thu, Feb 19, 2004 at 10:17:34AM +0100 or thereabouts, Dan Richter wrote:
> 
> In addition to -n (line number), you can use -<number>, which causes 
> grep to output <number> lines before and after the match:
> 
>    grep -n -3 'Free Software Foundation' GPL.txt
> 
> GNU grep allows you to use -A <num> and -B <num> to specify 
> (respectively) the number of lines before and after the match to output, 
> but I suspect that this behavior is less portable.

Alas, it appears that 'grep -<number>' is itself non portable.  SunOS 5.8
grep gives:

nu:cdaly>grep -3 test maxfall.tar
grep: illegal option -- 3
Usage: grep -hblcnsviw pattern file . . .

But of course, this is about _linux_ commands and it's so cool that everyone
else should do it...

Incidentally, Carla mentioned wildcards with find.  It's important to note
that the wildcard _must_ be inside single quotes (eg find . -name 'arrow*').
This protects the wildcard from expansion by the shell before find gets the
pattern.  Without the quotes, the command will expand to "find . -name
arrow.png" 'cos you had a file called 'arrow.png' in your home dir and
nothing else will be found.

Conor
-- 
Conor Daly,                   Please avoid sending me 
Met Eireann, Glasnevin Hill,  Word or PowerPoint attachments.
Dublin 9, Ireland             http://www.fsf.org/philosophy/no-word-attachments.html
Ph +3531 8064276 Fax +3531 8064247


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