Cfrgtkky

I have some text files from which I want to extract certain data. I want to extract some specific numbers from them. In particular I want to search the files for the first occurrence of string1 and take the numbers that follow it. That is, I want to take all numbers, dots, or minus signs and stop once another character is reached. Then I want to write away those numbers to a separate file.

Preferably I would be able to do this for multiple strings at once (so also look for string2, do the same there and write away the results in some listed format, say {numbers1,numbers2}. But this last part is less important.

How would I accomplish this?

I did not include specific data since was hoping there was a general solution for the question I asked. Such a tool would be generally useful in numerous occasions. (I tried to piece together a general solution from the various questions on how to extract a number from a specific string, but failed.)

The data would look something like

bla bla bla label1_5234_blablab_some_other_text_and_numbers_23343_blabla_more_text_and_numbers_maybe_label1_again_but_now_I_no_longer_care_about_what_comes_after blabla_label2_34343_this_is_some_other_number_want_to_be_able_to_extract_if_I_look_for_label2_instead_of_label1

label3 = -0.34343 

and_more_text_and_so_on_and_so_forth

The patterns to look for would then be label1_, label2_ or label3 =. (Of course it should work regardless of the exact form of label1. But since that apparently wasn't completely clear let me add another example.
height_2.3 blabla_bla_length_3.4, should give 2.3, 3.4 or {2.3,3.4} depending on whether we ask for height, length or both.)

And the output would be, if given one pattern to look for, say label1_

5234

or when looking for label3 =

-0.34343

Then in addition it would be nice if it could search for two things at once and group them. So for instance giving both patterns above outputting

{5234,-0.34343}

Finally it would be nice if it could group results for this for multiple files if fed multiple files:

{out1a,out1b}

{out2a,out2b}

If you want all the results from a single file grouped together, then it's likely easiest to slurp the whole of each file into memory and process it as one block. You can do that in perl by unsetting the line separator - the conventional way to do that in a perl one-liner is -0777.

Next you need a regular expression that matches a sequence of decimal digits, decimal separators etc. preceded by label[123]_ or label[123] =

Putting it together:

perl -0777nE 'say "{", (join ",", /label[123](?:_| = )K[0-9.+-]+/g), "}"' file1 file2 [...]

Note: I have not tried to address maybe_label1_again_but_now_I_no_longer_care_about_what_comes_after

sed solution

With $p holding the label regex, e.g. p='label[13](_| = )':

sed ':a;N;$!ba;s/n/ /g;s/'"$p"'[-.0-9]+/&n/g' | 

sed '/.*'"$p"'[-.0-9]+/!d;s/.*'"$p"'([-.0-9]+)/2/' | 

sed ':a;N;$!ba;s/n/,/g;s/.*/{&}/'

The first command removes linebreaks and adds a new one after every match, the second one removes lines without a match and extracts the numbers and the third one makes them comma-separated and encloses them in curly brackets.

$p must hold a valid regex and exactly one group (or you need to adjust the RHS part of the third substitution expression), for example:

p='label1(_)'

p='label3( = )'

p='label[13](_| = )'

p='(label1_|label3 = )'

p='(height|length)_'

Multiple different strings in the group are to be separated by |.

Examples

$ <input cat

bla bla bla label1_5234_blablab_some_other_text_and_numbers_23343_blabla_more_text_and_numbers_maybe_label1_again_but_now_I_no_longer_care_about_what_comes_after blabla_label2_34343_this_is_some_other_number_want_to_be_able_to_extract_if_I_look_for_label2_instead_of_label1

label3 = -0.34343 

and_more_text_and_so_on_and_so_forth

$ p='label1(_)'

$ <input sed ':a;N;$!ba;s/n/ /g;s/'"$p"'[-.0-9]+/&n/g' | sed '/.*'"$p"'[-.0-9]+/!d;s/.*'"$p"'([-.0-9]+)/2/' | sed ':a;N;$!ba;s/n/,/g;s/.*/{&}/'

5234

$ p='label3( = )'

$ <input sed ':a;N;$!ba;s/n/ /g;s/'"$p"'[-.0-9]+/&n/g' | sed '/.*'"$p"'[-.0-9]+/!d;s/.*'"$p"'([-.0-9]+)/2/' | sed ':a;N;$!ba;s/n/,/g;s/.*/{&}/'

-0.34343

$ p='label[13](_| = )'

$ <input sed ':a;N;$!ba;s/n/ /g;s/'"$p"'[-.0-9]+/&n/g' | sed '/.*'"$p"'[-.0-9]+/!d;s/.*'"$p"'([-.0-9]+)/2/' | sed ':a;N;$!ba;s/n/,/g;s/.*/{&}/'

{5234,-0.34343}

$ echo "height_2.3 blabla_bla_length_3.4" >>input

$ p='(height)_'

$ <input2 sed ':a;N;$!ba;s/n/ /g;s/'"$p"'[-.0-9]+/&n/g' | sed '/.*'"$p"'[-.0-9]+/!d;s/.*'"$p"'([-.0-9]+)/2/' | sed ':a;N;$!ba;s/n/,/g;s/.*/{&}/'

2.3

$ p='(height|length)_'

$ <input2 sed ':a;N;$!ba;s/n/ /g;s/'"$p"'[-.0-9]+/&n/g' | sed '/.*'"$p"'[-.0-9]+/!d;s/.*'"$p"'([-.0-9]+)/2/' | sed ':a;N;$!ba;s/n/,/g;s/.*/{&}/'

{2.3,3.4}

For single file

grep -oP "(?<=label1_)[0-9.+-]+[^_ ]+" ./file | head -n 1 >> ./tmpfile

grep -oP "(?<=label3 = )[0-9.+-]+[^_ ]+" ./file | head -n 1 >> ./tmpfile

paste -sd, ./tmpfile | awk '{ print "{"$0"}" }' >> ./newfile

rm ./tmpfile

For multiple files in a folder.

cd to the folder and run:

for file in *; do

if [ "$file" == "newfile" ] ; then continue; fi

grep -oP "(?<=label1_)[0-9.+-]+[^_ ]+" $file | head -n 1 >> ./tmpfile

grep -oP "(?<=label3 = )[0-9.+-]+[^_ ]+" $file | head -n 1 >> ./tmpfile

paste -sd, ./tmpfile | awk '{ print "{"$0"}" }' >> ./newfile

rm ./tmpfile

done