Can text be sorted twice?-CodePudding

I have an awk array that aggregates bytes up and downloaded. I can sort the output by either bytes down or up and pipe that to head for the top talkers; is it possible to output two sorts using different keys?

 zgrep ^1 20211014T00*.gz|awk '{print$3,$11,$6,$(NF-7)}'| awk 'NR>1{bytesDown[$1 " " $2] =$3;bytesUp[$1 " " $2] =$4} END {for(i in bytesDown) print bytesDown[i], bytesUp[i], i}'|sort -rn|head

Rather than parsing the source again to get the top uploads, I would like to be able to output the array again to "sort -rnk2|head".

I can see how I'd do it with a scratch file but is it possible/desirable to do it in memory? It's a bash shell on a 2 CPU Linux VM with 4GB of memory.

CodePudding user response：

Bash allows you to do that with process substitutions. It's not clear what you expect it to do with the data; printing both results to standard output is unlikely to be useful, so I send each to a separate file for later inspection.

zgrep ^1 20211014T00*.gz | 
awk '{print$3,$11,$6,$(NF-7)}' |
awk 'NR>1{bytesDown[$1 " " $2] =$3;bytesUp[$1 " " $2] =$4}
  END {for(i in bytesDown) print bytesDown[i], bytesUp[i], i}' |
tee >(sort -rn | head >first) |
sort -rnk2 | head >second

The double Awks could easily be refactored to a single Awk script. Something like this?

awk 'NR>1{bytesDown[$3 " " $11] =$6;bytesUp[$3 " " $11] =$(NF-7)}
    END { for(i in bytesDown) print bytesDown[i], bytesUp[i], i }'

CodePudding user response：

Your question isn't clear and there's no sample input/output to test with but this MAY be what you're trying to do:

zgrep '^1' 20211014T00*.gz|
awk '
    NR > 1 {
        key = $3 " " $11
        bytesdown[key]  = $6
        bytesup[key]  = $(NF-7)
    }
    END {
        cmd = "sort -rn | head"
        for ( key in bytesDown ) {
            print bytesDown[key], bytesUp[key], key | cmd
        }
        close(cmd)

        cmd = "sort -rnk2 | head"
        for ( key in bytesDown ) {
            print bytesDown[key], bytesUp[key], key | cmd
        }
        close(cmd)
    }
'

which could be written more concisely and efficiently as:

zgrep '^1' 20211014T00*.gz|
awk '
    NR > 1 {
        key = $3 " " $11
        bytesdown[key]  = $6
        bytesup[key]  = $(NF-7)
        if ( NR == 2 ) {
            max_bytesdown_key = key
            max_bytesup_key = key
        }
        else {
            if ( bytesdown[key] > bytesdown[max_bytesdown_key] ) {
                max_bytesdown_key = key
            }
            if ( bytesup[key] > bytesup[max_bytesup_key] ) {
                max_bytesup_key = key
            }
        }
    }
    END {
        print bytesdown[max_bytesdown_key], bytesup[max_bytesdown_key], max_bytesdown_key
        print bytesdown[max_bytesup_key], bytesup[max_bytesup_key], max_bytesup_key
    }
'