commit: 6b1ea77cf5befc19999701a73c64eb39f0dafacd Author: Kerin Millar <kfm <AT> plushkava <DOT> net> AuthorDate: Sun Jun 2 20:57:49 2024 +0000 Commit: Sam James <sam <AT> gentoo <DOT> org> CommitDate: Wed Jun 12 07:06:42 2024 +0000 URL: https://gitweb.gentoo.org/proj/gentoo-functions.git/commit/?id=6b1ea77c
Add the oldest() and newest() functions It compares potentially existing pathnames, printing the oldest and newest among them by modification time, respectively. $ . /lib/gentoo/functions.sh $ newest /etc/* /etc/environment.d $ printf '%s\0' /etc/* | newest /etc/environment.d Support for pathnames containing <newline> characters may be added once read -d becomes broadly supported. https://austingroupbugs.net/view.php?id=245 Signed-off-by: Kerin Millar <kfm <AT> plushkava.net> functions.sh | 74 ++++++++++++++++++++++++++++++++++++++++++---------------- test-functions | 39 +++++++++++++++++++++++++++++++ 2 files changed, 93 insertions(+), 20 deletions(-) diff --git a/functions.sh b/functions.sh index 0c35b2d..1548bd0 100644 --- a/functions.sh +++ b/functions.sh @@ -1,6 +1,6 @@ # Copyright 1999-2023 Gentoo Authors # Distributed under the terms of the GNU General Public License v2 -# shellcheck shell=sh disable=3043 +# shellcheck shell=sh disable=2209,3043 # This file contains a series of function declarations followed by some # initialisation code. Functions intended for internal use shall be prefixed @@ -401,7 +401,7 @@ is_int() # is_older_than() { - local ref has_gfind + local ref if [ "$#" -eq 0 ]; then warn "is_older_than: too few arguments (got $#, expected at least 1)" @@ -412,26 +412,39 @@ is_older_than() ref= fi shift + { test "$#" -gt 0 && printf '%s\0' "$@"; } \ + | "${genfun_bin_find}" -L -files0-from - ${ref:+-newermm} ${ref:+"${ref}"} -printf '\n' -quit \ + | read -r _ +} - # Check whether GNU find is installed by the name of "gfind". So as to - # avoid repeated PATH lookups, run the hash builtin in the present - # shell, prior to forking. - hash gfind 2>/dev/null; has_gfind=$(( $? == 0 )) +# +# Considers one or more pathnames and prints the one having the newest +# modification time. If at least one parameter is provided, all parameters shall +# be considered as pathnames to be compared to one another. Otherwise, the +# pathnames to be compared shall be read from the standard input as +# NUL-delimited records. If no pathnames are given, or those specified do not +# exist, the return value shall be greater than 0. In the case that two or more +# pathnames are candidates, the one having the lexicographically greatest value +# shall be selected. Pathnames containing newline characters shall be ignored. +# +newest() +{ + _select_by_mtime -r "$@" +} - for path; do - if [ -e "${path}" ]; then - printf '%s\0' "${path}" - fi - done | - { - set -- -L -files0-from - ${ref:+-newermm} ${ref:+"${ref}"} -printf '\n' -quit - if [ "${has_gfind}" -eq 1 ]; then - gfind "$@" - else - find "$@" - fi - } | - read -r _ +# +# Considers one or more pathnames and prints the one having the oldest +# modification time. If at least one parameter is provided, all parameters shall +# be considered as pathnames to be compared to one another. Otherwise, the +# pathnames to be compared shall be read from the standard input as +# NUL-delimited records. If no pathnames are given, or those specified do not +# exist, the return value shall be greater than 0. In the case that two or more +# pathnames are candidates, the one having the lexicographically lesser value +# shall be selected. Pathnames containing newline characters shall be ignored. +# +oldest() +{ + _select_by_mtime -- "$@" } # @@ -726,6 +739,24 @@ _print_args() EOF } +# +# See the definitions of oldest() and newest(). +# +_select_by_mtime() { + local sort_opt + + sort_opt=$1 + shift + if [ "$#" -ge 0 ]; then + printf '%s\0' "$@" + else + cat + fi \ + | "${genfun_bin_find}" -files0-from - -maxdepth 0 ! -path "*${genfun_newline}*" -printf '%T+ %p\n' \ + | sort "${sort_opt}" \ + | { IFS= read -r line && printf '%s\n' "${line#* }"; } +} + # # Determines whether the terminal on STDIN is able to report its dimensions. # Upon success, the number of columns shall be stored in genfun_cols. @@ -805,6 +836,9 @@ if [ "${BASH}" ]; then genfun_bin_true=$(type -P true) fi +# Store the name of the GNU find binary. Some platforms may have it as "gfind". +hash gfind 2>/dev/null && genfun_bin_find=gfind || genfun_bin_find=find + # Determine whether the use of color is to be wilfully avoided. if [ -n "${NO_COLOR}" ]; then # See https://no-color.org/. diff --git a/test-functions b/test-functions index 0c4a222..400ddb2 100755 --- a/test-functions +++ b/test-functions @@ -418,6 +418,44 @@ test_srandom() { iterate_tests 2 "$@" } +test_newest() { + set -- \ + ge 1 non-existent non-existent \ + ge 1 N/A N/A \ + \ + eq 0 newer/file N/A \ + eq 0 newer/file newer/file \ + eq 0 newer/file non-existent \ + eq 0 newer/file older/file \ + eq 0 non-existent newer/file \ + eq 0 older/file newer/file \ + \ + eq 0 older/file N/A \ + eq 0 older/file older/file \ + eq 0 older/file non-existent \ + ge 1 newer/file older/file \ + eq 0 non-existent older/file \ + ge 1 older/file newer/file + + row=0 + + callback() { + shift + test_description="newest $(_print_args "$@")" + row=$(( row + 1 )) + true | + if [ "${row}" -le 2 ]; then + newest "$@" + elif [ "${row}" -le 8 ]; then + test "$(newest "$@")" = "newer/file" + else + test "$(newest "$@")" = "older/file" + fi + } + + iterate_tests 4 "$@" +} + iterate_tests() { slice_width=$1 shift @@ -479,6 +517,7 @@ test_yesno || rc=1 test_die || rc=1 test_edo || rc=1 test_srandom || rc=1 +test_newest || rc=1 cleanup_tmpdir
