commit: fd79ab30122474ab5207ea001d92ffac677b5380
Author: Kerin Millar <kfm <AT> plushkava <DOT> net>
AuthorDate: Thu Jun 27 16:06:38 2024 +0000
Commit: Sam James <sam <AT> gentoo <DOT> org>
CommitDate: Fri Jun 28 17:39:01 2024 +0000
URL:
https://gitweb.gentoo.org/proj/gentoo-functions.git/commit/?id=fd79ab30
Add an experimental module for staging new ideas
The idea is to be able to write new functions without having to
initially commit to their being in the core library or, indeed, any of
the other modules. Experimental functions may be promoted or simply
dropped without warning if it is decided that they are insufficiently
useful to merit incorporation.
This initial commit defines the is_interactive() and prepend_ts()
functions.
Signed-off-by: Kerin Millar <kfm <AT> plushkava.net>
functions/experimental.sh | 53 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 53 insertions(+)
diff --git a/functions/experimental.sh b/functions/experimental.sh
new file mode 100644
index 0000000..f577fa7
--- /dev/null
+++ b/functions/experimental.sh
@@ -0,0 +1,53 @@
+# Copyright 2024 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+# shellcheck shell=sh disable=3043
+
+# This file contains functions considered experimental in nature. Any functions
+# defined here may eventually be promoted to the core library or to a distinct
+# module. They may also be dropped without warning, either because they were
+# not considered as being sufficiently within the scope of gentoo-functions as
+# a project or because they were deemed to be insufficiently useful. As such,
it
+# serves as a staging ground for new ideas. Note that GENFUN_API_LEVEL must
+# never be incremented on account of any changes made to this module.
+
+warn "sourcing the experimental module from gentoo-functions; no stability
guarantee is provided"
+
+#
+# Returns 0 provided that two conditions hold. Firstly, that the standard input
+# is connected to a tty. Secondly, that the standard output has not been
closed.
+# This technique is loosely based on the IO::Interactive::Tiny module from
CPAN.
+#
+is_interactive()
+{
+ test -t 0 && { true 3>&1; } 2>/dev/null
+}
+
+#
+# Continuously reads lines from the standard input, prepending each with a
+# timestamp before printing to the standard output. Timestamps shall be in the
+# format of "%FT%T%z", per strftime(3). Output buffering shall not be employed.
+#
+prepend_ts()
+{
+ if hash gawk 2>/dev/null; then
+ prepend_ts()
+ {
+ gawk '{ print strftime("%FT%T%z"), $0; fflush(); }'
+ }
+ elif hash ts 2>/dev/null; then
+ prepend_ts()
+ {
+ ts '%FT%T%z'
+ }
+ elif bash -c '(( BASH_VERSINFO >= 4 ))' 2>/dev/null; then
+ prepend_ts()
+ {
+ bash -c 'while read -r; do printf "%(%FT%T%z)T %s\n" -1
"${REPLY}"; done'
+ }
+ else
+ warn "prepend_ts: this function requires that either bash, gawk
or moreutils be installed"
+ return 1
+ fi
+
+ prepend_ts
+}
