commit: 1bd941e3de386fd04e23b23407d213868920dbd3
Author: Kerin Millar <kfm <AT> plushkava <DOT> net>
AuthorDate: Thu May 16 06:20:02 2024 +0000
Commit: Sam James <sam <AT> gentoo <DOT> org>
CommitDate: Fri May 17 01:40:19 2024 +0000
URL:
https://gitweb.gentoo.org/proj/gentoo-functions.git/commit/?id=1bd941e3
Make _eend() much faster in bash
This is accomplished by instead invoking the true binary and taking a
reading of the COLUMNS variable. However, this is only done in
situations where it can be expected to be reliable. Even as of
bash 5.3-alpha, the checkwinsize feature does not work reliably in a
subshell.
Signed-off-by: Kerin Millar <kfm <AT> plushkava.net>
functions.sh | 28 ++++++++++++++++++++--------
1 file changed, 20 insertions(+), 8 deletions(-)
diff --git a/functions.sh b/functions.sh
index 57f6aa2..1f547d0 100644
--- a/functions.sh
+++ b/functions.sh
@@ -469,14 +469,20 @@ _is_visible()
#
_update_columns()
{
- local ifs
-
- # The following use of stty(1) is portable as of POSIX Issue 8.
- ifs=$IFS
- IFS=' '
- # shellcheck disable=2046
- set -- $(stty size 2>/dev/null)
- IFS=$ifs
+ # Command substitutions are rather slow in bash. Using the COLUMNS
+ # variable helps but checkwinsize won't work properly in subshells.
+ # shellcheck disable=3028,3044
+ if [ "$$" = "${BASHPID}" ] && shopt -q checkwinsize; then
+ "${genfun_bin_true}"
+ set -- 0 "${COLUMNS}"
+ else
+ # The following use of stty(1) is portable as of POSIX Issue 8.
+ genfun_ifs=${IFS}
+ IFS=' '
+ # shellcheck disable=2046
+ set -- $(stty size 2>/dev/null)
+ IFS=${genfun_ifs}
+ fi
[ "$#" -eq 2 ] && is_int "$2" && [ "$2" -gt 0 ] && genfun_cols=$2
}
@@ -515,6 +521,12 @@ else
genfun_offset=0
fi
+# Store the path to the true binary. It is potentially used by _update_columns.
+if [ "${BASH}" ]; then
+ # shellcheck disable=3045
+ genfun_bin_true=$(type -P true)
+fi
+
# Determine whether the use of color is to be wilfully avoided.
if [ -n "${NO_COLOR}" ]; then
# See https://no-color.org/.
