Re: linecut (further refinement)

[Paul Eggert]

Steven Schubiger <address@hidden> writes:

> linecut performed a bit more than 3-times faster than the script).

Here's an Awk script that ran twice as fast as the script you used,
which suggests that scripting is still pretty competitive with C here,
if you choose a faster implementation.  I tested it using Mawk, on a
text file with 15,699,634 bytes and 514,573 lines.

#! /usr/bin/mawk

BEGIN { 
    sets[1, 1] = 1
    sets[1, 2] = 2
    sets[2, 1] = 20
    sets[2, 2] = 24
    sets[3, 1] = 50
    sets[3, 2] = 100
    sets[4, 1] = -30
    sets[4, 2] = -1
}

{ line[NR] = $0 }

END {
    for (i=1; i<=4; i++) {
        start = sets[i, 1]
        end = sets[i, 2]
        if (start < 0) start = NR + start 
        if (end < 0) end = NR + end
        for (current = start; current <= end; current++) print line[current]
    }
}