😎 TIL: ECMAScript / Javascript is influenced by AWK You're welcome #javascript 🤪

😎 You agree, don't you? 😎

🤓 How to print the first and the last line in a file? 🤓 awk 'NR==1; END{print}

🤔 Do you want to write better and portable AWK scripts? Of course you want 😄 💡 GAWK (GNU AWK) supports --lint: > awk --lint 'and($1,$2)' file.txt awk: cmd. line:1: warning: `and' is a gawk extension

🤔 Do you find your scripts with all these $1, $2 etc unreadable? 🤔 💡 Try giving them names: > docker ps | awk 'BEGIN{cont_id=1;image=2;}$image=="postgres"{print $cont_id}'

🤔 Is there an AWK script you don't understand? Post it here ⬇️

😎 While AWK does support if statements, patterns are often easier 💡

🤓 New week new trick! 🤓 🤔 Replace a string in AWK: > awk '{gsub("bob", "anna")}1' file.txt ➡️ replace "bob" with "anna" ➡️ 1st param can be a regex (eg. /bob/) ➡️ 3rd param is optional (default $0 / line) 💡sed might be more suitable for such tasks 😉

How to print only odd lines 🤓

A third of the participants has known AWK for more than ten years 🤯

For how long have you known about AWK? #Linux #DevOps

🤔 Did you know you can write a self-contained AWK script? 🤔 ➡️ Given a file: > cat script.awk #!/usr/bin/awk -f { print $0 } ➡️ Make it executable > chmod +x script.awk ➡️ And run it > ./script.awk file.txt 🐧 If only everything was so easy #Linux 🐧

😍 Last July, @lexfridman interviewed Brian Kernighan, one of the authors of AWK. Listen to Brian explaining why AWK is still very useful today. youtube.com/watch?v=W5kr7X7E…

🤔 How to print the container id of a running postgres docker container? 🤔 > docker ps | awk '/postgres/{print $1}' 😎 Easy, right?

😎 How to print all columns but the first? 😎 > awk '{$1="";$0=$0} NF=NF' file.txt 💡 Change to $1=$2="" to omit the second column as well 💡 The $0=$0 and NF=NF gymnastic is needed to make AWK recalculate what to print. If you don't do it, you might see leading spaces 😉

🤔 Did you ever pipe grep into AWK? 🤔 > grep x file.txt | awk '{print $1}' 💡 No need to grep first, AWK can do it: > awk '/x/{print $1}' file.txt ➡️ Before the command ({..}) is the pattern. The pattern can be a regex (between slashes) and matches on anything in the line

😎 How to count non-empty lines in AWK? 😎 > awk 'NF{cnt++}END{print cnt}' file.txt 💡 NF is the number of fields ➡️ true if there is at least one field (NF>0) 💡 END is only run at the end, so we print the variable 'cnt' when the entire file is processed #Linux #AWK

🤓 Another popular AWK question from StackOverflow: How to print all lines starting from the n-th? 🤔 > awk 'NR>=2' file.txt 💡 remember that the first line has NR=1 ➡️ the above prints from the 2nd line onwards