Extract pattern between a substring and first occurrence of numeric in a string

matching, sed, substring

Solution

There are quite a few ways to extract the data. The simplest form would be `grep`.

GNU `grep`:

You can grab the required data using GNU `grep` with PCRE option `-P`:

$ cat file
xxx_component1-1.0-2-2acd314.xc-linux-x86-64-Release-devel.r
xxx_component2-3.0-1-fg3sdhd.xc-linux-x86-64-Release-devel.r
xxx_component3-1.0-2-3gsjcgd.xc-linux-x86-64-Release-devel.r
xxx_component4-0.0-2-2acd314.xc-linux-x86-64-Release-devel.r

$ grep -oP '(?<=_)[^-]*' file
component1
component2
component3
component4

Here we use negative look behind assertion tell to capture everything from `_` to a `-` not incusive.

`awk`:

$ awk -F"[_-]" '{print $2}' file
component1
component2
component3
component4

Here we tell `awk` to use `-` and `_` as delimiters and print the second column.

`sed`:

Having said that, you can also use `sed` to extract required data using group capture:

$ sed 's/.*_\([^-]*\)-.*/\1/' file
component1
component2
component3
component4

The regex states that match any character zero or more times up to an `_`. From that point onwards, capture everything until a `-` in a group. In the replacement part we just use the data captured in the group by calling it using back reference, that is `\1`.

Problem

Following is the content of a file: ``` xxx_component1-1.0-2-2acd314.xc-linux-x86-64-Release-devel.r xxx_component2-3.0-1-fg3sdhd.xc-linux-x86-64-Release-devel.r xxx_component3-1.0-2-3gsjcgd.xc-linux-x86-64-Release-devel.r xxx_component4-0.0-2-2acd314.xc-linux-x86-64-Release-devel.r ``` I want to extract component names component1 component2 etc. This is what I tried: ``` for line in `sed -n -e '/^xxx-/p' $file` do comp=`echo $line | sed -e '/xxx-/,/[0-9]/p'` echo "comp - $comp" done ``` I also tried `sed -e 's/.*xxx-\(.*\)[^0-9].*/\1/'` This is based on some info on net. Please give me `sed` command and if possible also explain stepwise Part 2. I also need to extract version number from the string. version number starts with digit and ends with . followed by xc-linux. As you can see to maintain the uniqueness its has random alphanumeric characters ( length is 7) as part of the version number. For example : xxx_component1-1.0-2-2acd314.xc-linux-x86-64-Release-devel.r In this string the version number is : 1.0-2-2acd314

Original source