NAME

line - Greple module to produce result by line numbers

SYNOPSIS

greple -Mline

DESCRIPTION

This module allows you to use line numbers to specify patterns or regions which can be used in greple options.

-L=line numbers

Simply, next command will show 200th line with before/after 10 lines of the file:

greple -Mline -L 200 -C10 file

If you don't like lines displayed with color, use --nocolor option or set colormap to something do nothing like --cm=N.

Multiple lines can be specified by joining with comma:

greple -Mline -L 10,20,30

It is ok to use -L option multiple times, like:

greple -Mline -L 10 -L 20 -L 30

But this command produce nothing, because each line definitions are taken as a different pattern, and greple prints lines only when all patterns matched. You can relax the condition by --need 1 option in such case, then you will get expected result. Next example will display 10th, 20th and 30th lines in different colors.

greple -Mline -L 10 -L 20 -L 30 --need 1

Range can be specified by colon:

greple -Mline -L 10:20

You can also specify the step with range. Next command will print all even lines from line 10 to 20:

greple -Mline -L 10:20:2

Any of them can be omitted. Next commands print all, odd and even lines.

greple -Mline -L ::		# all lines
greple -Mline -L ::2	# odd lines
greple -Mline -L 2::2	# even lines

If start and end number is negative, they are subtracted from the maxmum line number. If the end number is prefixed by plus (`+') sign, it is summed with start number. Next commands print top and last 10 lines respectively.

greple -Mline -L :+9	# top 10 lines
greple -Mline -L -9:	# last 10 lines

Next example print all lines of the file, each line in four different colors.

greple -Mline -L=1::4 -L=2::4 -L=3::4 -L=4::4 --need 1

If forth parameter is given, it describes how many lines is included in that step cycle. For example, next command prints top 3 lines in every 10 lines.

greple -Mline -L ::10:3

When step count is omitted, forth value is used if available. Next command print every 10 lines in different colors.

greple -Mline -L :::10 --ci=A /etc/services

-Mline line numbers

If a line number argument immediately follows -Mline module option, it is recognized as a line number without the -L option. Thus, the above example can also be specified as follows:

greple -Mline ::10:3

L=line numbers

This notation just define function spec, which can be used in patterns, as well as blocks and regions. Actually, -L=line is equivalent to --le L=line.

Next command show patterns found in line number 1000-2000 area.

greple -Mline --inside L=1000:+1000 pattern

Next command prints all 10 line blocks which include the pattern.

greple -Mline --block L=:::10 pattern

In this case, however, it is faster and easier to use regex.

greple --block '(.*\n){1,10}' pattern

--offload=command

Set the offload command to retrieve the desired line numbers. The numbers in the output, starting at the beginning of the line, are treated as line numbers. This is compatible with grep -n output.

Next command print 10 to 20 lines.

greple -Mline --offload 'seq 10 20'

Using this module, it is impossible to give single L in command line arguments. Use like --le=L to search letter L. You have a file named L? Stop substitution by placing -- before the target files.

SEE ALSO

Getopt::EX::Numbers