From ebc64de22f84f62dc48e5d16ec5d12ca82222b74 Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Mon, 28 Oct 2024 13:26:01 +0100
Subject: [PATCH] udevadm: automatically anable JSON-SEQ in case JSON is used
 for "udevadm info -a"

We are going to output a series of JSON objects, hence let's
automatically enable JSON-SEQ output mode, as we usually do.

"jq --seq" supports this natively, hence this should not really restrict
us.

Follow-up for: 67ea8a4c0edef33b1775536bc81d5de2c8ac4d88
---
 man/udevadm.xml               | 5 +++++
 src/udev/udevadm-info.c       | 2 ++
 test/units/TEST-17-UDEV.10.sh | 4 ++--
 3 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/man/udevadm.xml b/man/udevadm.xml
index 556f845dce..eb77356d86 100644
--- a/man/udevadm.xml
+++ b/man/udevadm.xml
@@ -167,6 +167,11 @@
             <para>Print all sysfs properties of the specified device that can be used
             in udev rules to match the specified device. It prints all devices
             along the chain, up to the root of sysfs that can be used in udev rules.</para>
+
+            <para>This switch supports JSON output mode (see <option>--json=</option> below). Note that
+            because this switch generates multiple JSON objects, JSON-SEQ mode is automatically enabled
+            (RFC7464). (Note: tools such as <ulink url="https://jqlang.github.io/jq/manual/">jq</ulink>
+            natively support JSON-SEQ via the <option>--seq</option> switch.)</para>
           </listitem>
         </varlistentry>
         <varlistentry>
diff --git a/src/udev/udevadm-info.c b/src/udev/udevadm-info.c
index 30f34b4958..57f063b010 100644
--- a/src/udev/udevadm-info.c
+++ b/src/udev/udevadm-info.c
@@ -274,6 +274,8 @@ static int print_device_chain_in_json(sd_device *device) {
 
         assert(device);
 
+        arg_json_format_flags |=SD_JSON_FORMAT_SEQ;
+
         r = print_all_attributes_in_json(device, /* is_parent = */ false);
         if (r < 0)
                 return r;
diff --git a/test/units/TEST-17-UDEV.10.sh b/test/units/TEST-17-UDEV.10.sh
index 1808e1975b..7ca05f5287 100755
--- a/test/units/TEST-17-UDEV.10.sh
+++ b/test/units/TEST-17-UDEV.10.sh
@@ -71,8 +71,8 @@ udevadm info --query symlink --root /sys/class/net/$netdev
 (! udevadm info -q hello -r /sys/class/net/$netdev)
 udevadm info -a /sys/class/net/$netdev
 udevadm info -a --json=off /sys/class/net/$netdev
-udevadm info -a --json=pretty /sys/class/net/$netdev | jq . >/dev/null
-udevadm info -a --json=short /sys/class/net/$netdev | jq . >/dev/null
+udevadm info -a --json=pretty /sys/class/net/$netdev | jq --seq . >/dev/null
+udevadm info -a --json=short /sys/class/net/$netdev | jq --seq . >/dev/null
 udevadm info -t >/dev/null
 udevadm info --tree /sys/class/net/$netdev
 udevadm info -x /sys/class/net/$netdev