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linuxbashcsh

Extract one word after a specific word on the same line

How can I extract a word that comes after a specific word in Linux (csh)? More precisely, I have a file which has a single line which looks like this:

[some useless data] --pe_cnt 100 --rd_cnt 1000 [some more data]

I want to extract the number 100 which is after the --pe_cnt word. I cannot use sed as that works only if you want to extract an entire line. Maybe I can use awk?

Also, I have multiple files that have different values instead of 100 so I need something that extracts the value but doesn't depend on the value.

Solution

  • With awk:

    awk '{for(i=1;i<=NF;i++) if ($i=="--pe_cnt") print $(i+1)}' inputFile

    Basically loop over each word of the line. When you find the first you are looking for, grab the next word and print it.

    With grep: 

    grep -oP "(?<=--pe_cnt )[^ ]+" inputFile