1 files changed, 29 insertions, 0 deletions
diff --git a/util/maptty.sh b/util/maptty.sh
new file mode 100755
index 0000000000..092b820f85
--- /dev/null
+++ b/util/maptty.sh
@@ -0,0 +1,29 @@
+#!/bin/bash
+# Copyright 2021 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+# This script shows mapping of /dev/ttyUSBx links to actual device files in
+# the /dev tree. The mapping makes it easy to follow various connected devices
+# to their /dev/ttyUSBx links.
+
+TMPF=$(mktemp '/tmp/maptty.XXXXX')
+trap 'rm -rf ${TMPF}' EXIT
+
+# Create a text file each line in which maps soft links found in /dev to their
+# actual device files, in particular to /dev/ttyUSBx devices.
+for f in $(find /dev -type l | grep -Ev '(pci-|char/)'); do
+  rn="$(readlink -f "${f}")";
+  echo "${rn}|${f}" >> "${TMPF}"
+done
+
+# For all /dev/ttyUSBx devices print all their soft links.
+for n in $(ls /dev/ttyUSB* | cut -c12- | sort -n); do
+  tty="/dev/ttyUSB${n}"
+  links=( $(awk -F'|' -vtty="${tty}" '{if ($1 == tty) {print $2}}' "${TMPF}" |
+              sort) )
+  printf "%-13s %s\n" "${tty}" "${links[0]}"
+  for link in "${links[@]:1}"; do
+    printf "%13s %s\n" " " "${link}"
+  done
+done