"awk" reaplacement for "head"

[lzadjsf]

I met an issue then head not works with mjson.tool.
We have replaced it with following code

awk 'BEGIN { i=0 } { ++i; if (i<=30) { print $0; } }'

Where 30 is amount of string have to be selected.

In the end I've got following logstashzabbix.sh script
#!/bin/bash
case $1 in
status )
initctl status logstash | grep -q running && echo 1 || echo 0 ;;
heap_bytes )
curl -s http://localhost:9600//_node/stats/jvm | python -mjson.tool | grep "heap_used_in_bytes | awk '{ print $2 }' | sed 's/,//' ;;
heap_percent )
curl -s http://localhost:9600//_node/stats/jvm | python -mjson.tool | grep "heap_used_percent | awk '{ print $2 }' | sed 's/,//' ;;
heap_max )
curl -s http://localhost:9600//_node/stats/jvm | python -mjson.tool | grep "heap_max_in_bytes | awk '{ print $2 }' | sed 's/,//' ;;
events_in )
curl -s http://localhost:9600//_node/stats/pipeline | python -mjson.tool | awk 'BEGIN { i=0 } { ++i; if (i<=10) { print $0; } }' | grep "in | awk '{ print $2 }' | sed 's/,//' ;;
events_filtered )
curl -s http://localhost:9600//_node/stats/pipeline | python -mjson.tool | awk 'BEGIN { i=0 } { ++i; if (i<=10) { print $0; } }' | grep "filtered | awk '{ print $2 }' | sed 's/,//' ;;
events_out )
curl -s http://localhost:9600//_node/stats/pipeline | python -mjson.tool | awk 'BEGIN { i=0 } { ++i; if (i<=11) { print $0; } }' | grep "out | awk '{ print $2 }' | sed 's/,//' ;;
failures )
curl -s http://localhost:9600//_node/stats/pipeline | python -mjson.tool | grep "failures | awk '{ print $2 }' | sed 's/,//' ;;
esac

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