udevadm: improve symlink query output

Implement the TODO item for `udevadm info -q symlink`: keep the default space-separated output pager-free, and make `--value` print one symlink per line with an empty separator line between devices.
2026-08-02 19:16:19 +09:00
parent 56d2162bff
commit 574eed3b0d
4 changed files with 105 additions and 9 deletions
@@ -0,0 +1,88 @@
+#!/usr/bin/env bash
+# SPDX-License-Identifier: LGPL-2.1-or-later
+set -ex
+set -o pipefail
+
+# shellcheck source=test/units/util.sh
+. "$(dirname "$0")"/util.sh
+
+assert_array_contains() {
+    local needle="${1:?}"
+    local item
+
+    shift
+    for item in "$@"; do
+        [[ "$item" == "$needle" ]] && return 0
+    done
+
+    echo >&2 "FAIL: '$needle' not found"
+    return 1
+}
+
+# shellcheck disable=SC2329
+cleanup() {
+    set +e
+
+    rm -f "$rules"
+    udevadm control --reload
+    udevadm trigger --settle --action change /dev/null /dev/full
+    rm -rf /dev/test-udevadm-symlink-query
+}
+
+rules="/run/udev/rules.d/99-test-17.symlink-query.rules"
+
+trap cleanup EXIT
+
+mkdir -p "${rules%/*}"
+cat >"$rules" <<'EOF'
+SUBSYSTEM=="mem", KERNEL=="null", SYMLINK+="test-udevadm-symlink-query/null-a"
+SUBSYSTEM=="mem", KERNEL=="null", SYMLINK+="test-udevadm-symlink-query/null-b"
+SUBSYSTEM=="mem", KERNEL=="full", SYMLINK+="test-udevadm-symlink-query/full-a"
+SUBSYSTEM=="mem", KERNEL=="full", SYMLINK+="test-udevadm-symlink-query/full-b"
+EOF
+udevadm control --reload
+udevadm trigger --settle --action change /dev/null /dev/full
+
+read -r -a null_links < <(udevadm info -q symlink /dev/null)
+read -r -a full_links < <(udevadm info -q symlink /dev/full)
+
+assert_array_contains "test-udevadm-symlink-query/null-a" "${null_links[@]}"
+assert_array_contains "test-udevadm-symlink-query/null-b" "${null_links[@]}"
+assert_array_contains "test-udevadm-symlink-query/full-a" "${full_links[@]}"
+assert_array_contains "test-udevadm-symlink-query/full-b" "${full_links[@]}"
+
+mapfile -t links_by_value < <(udevadm info -q symlink --value /dev/null /dev/full)
+value_null_links=()
+value_full_links=()
+n_separators=0
+
+for link in "${links_by_value[@]}"; do
+    if [[ -z "$link" ]]; then
+        n_separators=$((n_separators + 1))
+        continue
+    fi
+
+    case "$n_separators" in
+        0)
+            value_null_links+=("$link")
+            ;;
+        1)
+            value_full_links+=("$link")
+            ;;
+        *)
+            assert_not_reached
+    esac
+done
+
+assert_eq "$n_separators" 2
+assert_eq "${#value_null_links[@]}" "${#null_links[@]}"
+assert_eq "${#value_full_links[@]}" "${#full_links[@]}"
+
+for link in "${null_links[@]}"; do
+    assert_array_contains "$link" "${value_null_links[@]}"
+done
+for link in "${full_links[@]}"; do
+    assert_array_contains "$link" "${value_full_links[@]}"
+done
+
+exit 0