how to use regex pattern matching to get data from file?

ranjit · 10-17-2011, 04:03 AM

hi

I need pull out values from file using regex pattern matching.

ex:-
cpu_max=58000
cpu_min=12000

i need to read the file match the pattern and extract the string.since i am still a newbie in shell scripting any examples will be of great help.thanks in advance

grail · 10-17-2011, 04:10 AM

Well it depends on what you want to use, ie. bash, sed, awk, perl, ...

Try searching google for 'regular expressions', I am certain many of the hits will help.

ranjit · 10-17-2011, 04:12 AM

i need to use bash.

grail · 10-17-2011, 04:46 AM

Some information on bash regular expressions can be found here.

Also the top 4 responses in google to 'bash regular expressions', one of which leads to link above, all seem very apt.

theNbomr · 10-17-2011, 02:09 PM

Quote:

Originally Posted by ranjit

hi

I need pull out values from file using regex pattern matching.

ex:-
cpu_max=58000
cpu_min=12000

i need to read the file match the pattern and extract the string.since i am still a newbie in shell scripting any examples will be of great help.thanks in advance

The universe of regular expressions matching your data is virtually infinite. You would be well served to describe in words how you need to match your dataset. Use terminology that describes constant patterns such as 'numeric characters', 'preceding/following underscores', 'exactly matching cpu_min', etc. Expressions that describe the content and relationships of elements of your dataset will start to translate very quickly into regular expression syntax in your code. Be verbose in your description.
--- rod.