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From: gazelle@shell.xmission.com (Kenny McCormack)
Newsgroups: comp.unix.shell
Subject: Splitting in shell (bash)
Date: Sat, 9 Nov 2024 16:19:17 -0000 (UTC)
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There is a feature that is prominently missing from the shell language (I
am speaking primarily of bash here) - which is the ability to split a
string on a delimiter.  This is a common operation in most other
text-processing oriented languages (AWK, Perl, etc).

First note/caveat: I'm not interested in any solution involving IFS, for
two reasons:
    1) IFS-based solutions never work for me.
    2) Changing IFS is inherently dangerous, because, well, IFS itself in
	inherently dangerous.  Yes, I know it has been somewhat de-fanged
	recently - but it is still dangerous.

Anyway, the point of this thread is that I have recently developed a good
solution for this, using bash's "mapfile" command.  Suppose we have a
string in a variable (foo) like: foo;bar;bletch

I.e., with ; as the delimiter.

This works well, with a couple of caveats:

	mapfile -td ';' <<< "$foo"

Caveats:
    1) You can only have one, single character delimiter.  It'd be nice if
	you could have a reg-exp, like in GAWK.
    2) If the output you're processing comes from a process, as is usually
	the case, special care must be taken:

	mapfile -td ';' < <(someprocess | awk 1 ORS=)

The point is that since ';' is now the delimiter, the newline at the end of
the line coming from someprocess is not treated as a delimiter, so it must
be disposed of with the AWK script.  It'd be nice if you could make both
';' and '\n' be recognized as delimiters.

But other than those two caveats, it works well.

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