App::Greple::tee - module to replace matched text by the external command result
greple -Mtee command -- ...
Greple's -Mtee module sends matched text part to the given filter command, and replace them by the command result. The idea is derived from the command called teip. It is like bypassing partial data to the external filter command.
Filter command follows module declaration (-Mtee) and terminates by
two dashes (--). For example, next command call command tr
command with a-z A-Z arguments for the matched word in the data.
greple -Mtee tr a-z A-Z -- '\w+' ...
Above command convert all matched words from lower-case to upper-case. Actually this example itself is not so useful because greple can do the same thing more effectively with --cm option.
By default, the command is executed as a single process, and all matched data is sent to the process mixed together. If the matched text does not end with newline, it is added before sending and removed after receiving. Input and output data are mapped line by line, so the number of lines of input and output must be identical.
Using --discrete option, individual command is called for each matched text area. You can tell the difference by following commands.
greple -Mtee cat -n -- copyright LICENSE
greple -Mtee cat -n -- copyright LICENSE --discrete
Lines of input and output data do not have to be identical when used with --discrete option.
Version 0.9902
-
--discrete
Invoke new command individually for every matched part.
-
--fillup
Combine a sequence of non-blank lines into a single line before passing them to the filter command. Newline characters between wide width characters are deleted, and other newline characters are replaced with spaces.
-
--blocks
Normally, the area matching the specified search pattern is sent to the external command. If this option is specified, not the matched area but the entire block containing it will be processed.
For example, to send lines containing the pattern
footo the external command, you need to specify the pattern which matches to entire line:greple -Mtee cat -n -- '^.*foo.*\n' --allBut with the --blocks option, it can be done as simply as follows:
greple -Mtee cat -n -- foo --blocksWith --blocks option, this module behave more like teip(1)'s -g option. Otherwise, the behavior is similar to teip(1) with the -o option.
Do not use the --blocks with the --all option, since the block will be the entire data.
-
--squeeze
Combines two or more consecutive newline characters into one.
First of all, whenever you can do it with the teip command, use it. It is an excellent tool and much faster than greple.
Because greple is designed to process document files, it has many features that are appropriate for it, such as match area controls. It might be worth using greple to take advantage of those features.
Also, teip cannot handle multiple lines of data as a single unit, while greple can execute individual commands on a data chunk consisting of multiple lines.
Next command will find text blocks inside perlpod(1) style document included in Perl module file.
greple --inside '^=(?s:.*?)(^=cut|\z)' --re '^(\w.+\n)+' tee.pm
You can translate them by DeepL service by executing the above command convined with -Mtee module which calls deepl command like this:
greple -Mtee deepl text --to JA - -- --fillup ...
The dedicated module App::Greple::xlate::deepl is more effective for this purpose, though. In fact, the implementation hint of tee module came from xlate module.
Next command will find some indented part in LICENSE document.
greple --re '^[ ]{2}[a-z][)] .+\n([ ]{5}.+\n)*' -C LICENSE
a) distribute a Standard Version of the executables and library files,
together with instructions (in the manual page or equivalent) on where to
get the Standard Version.
b) accompany the distribution with the machine-readable source of the Package
with your modifications.
You can reformat this part by using tee module with ansifold command:
greple -Mtee ansifold -rsw40 --prefix ' ' -- --discrete --re ...
a) distribute a Standard Version of
the executables and library files,
together with instructions (in the
manual page or equivalent) on where
to get the Standard Version.
b) accompany the distribution with the
machine-readable source of the
Package with your modifications.
The --discrete option will start multiple processes, so the process
will take longer to execute. So you can use --separate '\r' option
with ansifold which produce single line using CR character instead
of NL.
greple -Mtee ansifold -rsw40 --prefix ' ' --separate '\r' --
Then convert CR char to NL after by tr(1) command or some.
... | tr '\r' '\n'
Consider a situation where you want to grep for strings from
non-header lines. For example, you may want to search for Docker image
names from the docker image ls command, but leave the header line.
You can do it by following command.
greple -Mtee grep perl -- -Mline -L 2: --discrete --all
Option -Mline -L 2: retrieves the second to last lines and sends
them to the grep perl command. The option --discrete is required
because the number of lines of input and output changes, but since the
command is only executed once, there is no performance drawback.
If you try to do the same thing with the teip command,
teip -l 2- -- grep will give an error because the number of output
lines is less than the number of input lines. However, there is no
problem with the result obtained.
$ cpanm App::Greple::tee
App::Greple::tee, https://github.com/kaz-utashiro/App-Greple-tee
https://github.com/greymd/teip
App::Greple, https://github.com/kaz-utashiro/greple
https://github.com/tecolicom/Greple
The --fillup option will remove spaces between Hangul characters when
concatenating Korean text.
Kazumasa Utashiro
Copyright © 2023 Kazumasa Utashiro.
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.