1 files changed, 107 insertions, 0 deletions
diff --git a/rule_generator.functions b/rule_generator.functions
new file mode 100644
index 0000000..ca290cc
--- /dev/null
+++ b/rule_generator.functions
@@ -0,0 +1,107 @@
+# functions used by the udev rule generator
+#
+# This program is free software; you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by the
+# Free Software Foundation version 2 of the License.
+
+PATH='/usr/sbin:/usr/bin'
+
+# Read a single line from file $1 in the $DEVPATH directory.
+# The function must not return an error even if the file does not exist.
+sysread() {
+	local file="$1"
+	[ -e "/sys$DEVPATH/$file" ] || return 0
+	local value
+	read value < "/sys$DEVPATH/$file" || return 0
+	echo "$value"
+}
+
+sysreadlink() {
+	local file="$1"
+	[ -e "/sys$DEVPATH/$file" ] || return 0
+	readlink -f /sys$DEVPATH/$file 2> /dev/null || true
+}
+
+# Return true if a directory is writeable.
+writeable() {
+	if ln -s test-link $1/.is-writeable 2> /dev/null; then
+		rm -f $1/.is-writeable
+		return 0
+	else
+		return 1
+	fi
+}
+
+# Create a lock file for the current rules file.
+lock_rules_file() {
+	[ -e /dev/.udev/ ] || return 0
+
+	RULES_LOCK="/dev/.udev/.lock-${RULES_FILE##*/}"
+
+	retry=30
+	while ! mkdir $RULES_LOCK 2> /dev/null; do
+		if [ $retry -eq 0 ]; then
+			 echo "Cannot lock $RULES_FILE!" >&2
+			 exit 2
+		fi
+		sleep 1
+		retry=$(($retry - 1))
+	done
+}
+
+unlock_rules_file() {
+	[ "$RULES_LOCK" ] || return 0
+	rmdir $RULES_LOCK || true
+}
+
+# Choose the real rules file if it is writeable or a temporary file if not.
+# Both files should be checked later when looking for existing rules.
+choose_rules_file() {
+	local tmp_rules_file="/dev/.udev/tmp-rules--${RULES_FILE##*/}"
+	[ -e "$RULES_FILE" -o -e "$tmp_rules_file" ] || PRINT_HEADER=1
+
+	local retry=5
+	while :;
+	do
+		if [ $retry -eq 0 ]; then
+			echo "$RULES_FILE not writeable!" >&2
+			exit 2
+		elif writeable ${RULES_FILE%/*}; then
+			RO_RULES_FILE='/dev/null'
+			break
+		fi
+		sleep 1
+		retry=$(($retry - 1))
+	done
+}
+
+# Return the name of the first free device.
+raw_find_next_available() {
+	local links="$1"
+
+	local basename=${links%%[ 0-9]*}
+	local max=-1
+	for name in $links; do
+		local num=${name#$basename}
+		[ "$num" ] || num=0
+		[ $num -gt $max ] && max=$num
+	done
+
+	local max=$(($max + 1))
+	# "name0" actually is just "name"
+	[ $max -eq 0 ] && return
+	echo "$max"
+}
+
+# Find all rules matching a key (with action) and a pattern.
+find_all_rules() {
+	local key="$1"
+	local linkre="$2"
+	local match="$3"
+
+	local search='.*[[:space:],]'"$key"'"('"$linkre"')".*'
+	echo $(sed -n -r -e 's/^#.*//' -e "${match}s/${search}/\1/p" \
+		$RO_RULES_FILE \
+		$([ -e $RULES_FILE ] && echo $RULES_FILE) \
+		2>/dev/null)
+}