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Home > Archive > Unix Shell > September 2007 > Help with String Extraction
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| Author |
Help with String Extraction
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| Vishal Sharma 2007-09-26, 7:31 am |
| Hello All,
My requirement is:
This is my file status.txt
server0 up 6 days 4:42 load average: 0.01 0.02 0.03
server1 up 8 days 22:54 load average: 0.01 0.06 0.05
server2 up 4 days 2:03 load average: 0.02 0.01 0.01
server3 up 7 days 22:46 load average: 0.01 0.03 0.04
i want to extract parse this file such that the output looks like
this:
server0 load average: 0.01 0.02 0.03
server1 load average: 0.01 0.06 0.05
server2 load average: 0.02 0.01 0.01
server3 load average: 0.01 0.03 0.04
How do i use sed/awk combination to achieve the above output.
Thanks in advance.
Regards,
Vishal Sharma
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| mr.bmonroe@gmail.com 2007-09-26, 1:26 pm |
| On Sep 26, 3:22 am, Vishal Sharma <visha...@gmail.com> wrote:
> This is my file status.txt
>
> server0 up 6 days 4:42 load average: 0.01 0.02 0.03
> server1 up 8 days 22:54 load average: 0.01 0.06 0.05
> server2 up 4 days 2:03 load average: 0.02 0.01 0.01
> server3 up 7 days 22:46 load average: 0.01 0.03 0.04
>
> i want to extract parse this file such that the output looks like
> this:
>
> server0 load average: 0.01 0.02 0.03
> server1 load average: 0.01 0.06 0.05
> server2 load average: 0.02 0.01 0.01
> server3 load average: 0.01 0.03 0.04
>
> How do i use sed/awk combination to achieve the above output.
Why use sed or awk when you can do it in the shell?
$ while read -r <&3 a b c d e f
> do
> printf "%s\t\t%s\n" "${a}" "${f}"
> done 3<status.txt
Thanks
--Brett
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| Ed Morton 2007-09-26, 1:26 pm |
| mr.bmonroe@gmail.com wrote:
> On Sep 26, 3:22 am, Vishal Sharma <visha...@gmail.com> wrote:
>
>
>
> Why use sed or awk when you can do it in the shell?
Because either sed and awk are the right tools for the job.
> $ while read -r <&3 a b c d e f
>
>
Either of these is simpler:
sed 's/ .*load/ load/' status.txt
awk 'sub(/ .*load/," load")' status.txt
Regards,
Ed.
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| Chris F.A. Johnson 2007-09-26, 7:20 pm |
| On 2007-09-26, mr.bmonroe@gmail.com wrote:
> On Sep 26, 3:22 am, Vishal Sharma <visha...@gmail.com> wrote:
>
> Why use sed or awk when you can do it in the shell?
If the file is more than a fairly small number of lines (25? 50?
100?), it will execute much more slowly than sed or awk.
[vbcol=seagreen]
> $ while read -r <&3 a b c d e f
--
Chris F.A. Johnson, author <http://cfaj.freeshell.org/shell/>
Shell Scripting Recipes: A Problem-Solution Approach (2005, Apress)
===== My code in this post, if any, assumes the POSIX locale
===== and is released under the GNU General Public Licence
| |
| Stephane CHAZELAS 2007-09-26, 7:20 pm |
| 2007-09-26, 17:47(-04), Chris F.A. Johnson:
[...]
>
> If the file is more than a fairly small number of lines (25? 50?
> 100?), it will execute much more slowly than sed or awk.
[...]
Agreed, but overall, a shell being over and before all a command
line interpreter doing something "in the shell" should mean, do
it with some commands called by the shell.
--
Stéphane
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| Chris F.A. Johnson 2007-09-26, 7:20 pm |
| On 2007-09-26, Stephane CHAZELAS wrote:
> 2007-09-26, 17:47(-04), Chris F.A. Johnson:
> [...]
> [...]
>
> Agreed, but overall, a shell being over and before all a command
> line interpreter
The shell is a command line interpreter that includes a full
programming language. There's no good reason not to use it as such.
> doing something "in the shell" should mean, do it with some commands
> called by the shell.
That is not true even with a Bourne shell, though then you _would_
have to use more external commands. There is absolutely no
justification for that attitude with a POSIX shell.
--
Chris F.A. Johnson, author <http://cfaj.freeshell.org/shell/>
Shell Scripting Recipes: A Problem-Solution Approach (2005, Apress)
===== My code in this post, if any, assumes the POSIX locale
===== and is released under the GNU General Public Licence
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