How to extract data from a file and construct a filename from one of the values

Question

I'm trying to pull two values from a configuration file and write them to a new file. The hard part is that I want the name of the new file to be determined by one of the values in the input file.

The values I'm trying to pull are "Build_Version" and the four-letter acronym from the Docker name ("docker_Name"). For example, if the file says docker_Name='bcbs_pr-app-01', I want only the "bcbs". And I want to write them to a file with the build's name, such as bcbs_build.txt.

Here is an excerpt from the log file:

nonSSL_port=80  # FOR STAGING 
Build_Type=prod 
Build_Version=9.0.00.01_134143 
docker_Name='bcbs-pr-app-01'

The desired file output is

bcbs
9.0.00.01_134143 

I came up with a sed command that worked for pulling the values I wanted

sed -n -e '/Build_Version=/p' -e '/docker_Name=/p' environment-info.conf > build_version.txt

but this extracts the Build_Version= and docker_Name= lines in their entirety, and I want only the Build_Version and docker name values. And I still need to figure out how to name the file with the four-letter Docker name acronym (bcbs).

Answer 1

That file looks like sh syntax. So, if that file is indeed a configuration file intended to be sourced in sh scripts, just do:

. ./environment-info.conf &&
  printf '%s\n' "${docker_Name%%-*}" "$Build_Version" > "${docker_Name%%-*}_build.txt"

Answer 2

1) alternating your sed, to a) remove first single quote of docker_Name, b) remove -pr-app-01' (including the last single quote), c) remove the <value>= part:

 sed -n "/Build_Version=/s/.*=//p;/docker_Name=/s/.*=//;s/'//;s/-.*//p"

Where /match/s/pattern/replacement/ replaces pattern with replacement at a matching line. If replacement is an empty string, it is effectively removed. Note that I switched from single to double quotes to handle the single quote in your string and that you can use wildcards * . to match more complex strings and combine sed commands with a semi-colon.

2) We read in the two results as a BASH array:

values=( $( sed -n "/Build_Version=/s/.*=//p;/docker_Name=/s/.*=//;s/'//;s/-.*//p" file ) )

Where array=( value1 value2 value3 ) and $(do this command)

3) We use the array for our purposes, note that the counter starts at 0:

echo ${values[1]} > ${values[1]}
echo ${values[0]} >> ${values[1]}

Where we address an entry of an array via the array name and the intex of the entry ${array[intex]}.

Answer 3

Do you have to use sed for this? grep and perl can do what you need.

grep 'Build_Type\|docker_Name' environment-info.conf | perl -pe "s|docker_Name='(.*?)-.*|docker_Name=\1|" > build_version.txt

Answer 4

Using GNU sed:

sed -nr "s/^Build_Version=([^=]+)$/\1/p; s/^docker_Name='([^-]+).*/\1/p" file.txt

We are using capturing groups to get desired portions from the relevant lines. It has two parts:

• s/^Build_Version=([^=]+)$/\1/ gets us 9.0.00.01_134143

• s/^docker_Name='([^-]+).*/\1/ gets us bcbs

To save the output to build_version.txt:

sed -nr "s/^Build_Version=([^=]+)$/\1/p; s/^docker_Name='([^-]+).*/\1/p" \
        file.txt >build_version.txt

Example:

% cat file.txt 
nonSSL_port=80  # FOR STAGING 
Build_Type=prod 
Build_Version=9.0.00.01_134143 
docker_Name='bcbs-pr-app-01'

% sed -nr "s/^Build_Version=([^=]+)$/\1/p; s/^docker_Name='([^-]+).*/\1/p" file.txt
9.0.00.01_134143 
bcbs

Answer 5

You are looking for a way to name the file with four letters from docker name. That can be achieved by the below command, which will assign the four letters to a variable called File_Name.

File_Name=`cat file | grep "docker_Name" | awk -F"'" '{print $2}' | awk -F'-' '{print $1}'`

As mentioned in above answers below command will assign the docker_Name and build_version to an array called values:

values=($(sed -n "/docker_Name=/s/.*=//;s/'//;s/-.*//p;/Build_Version=/s/.*=//p" file))

We are accessing the array in reverse order to capture the output the way you want:

for i in 1 0; do echo ${values[$i]} >> $File_Name.txt; done

File will be ready with name you want and cat will display its content:

% cat bcbs.txt
bcbs
9.0.00.01_134143