extras/rule_generator/write_cd_rules

   1 #!/bin/sh -e
   2
   3 # This script is run if an optical drive lacks a rule for persistent naming.
   4 #
   5 # It adds symlinks for optical drives based on the device class determined
   6 # by cdrom_id and used ID_PATH to identify the device.
   7 #
   8 # (C) 2006 Marco d'Itri <md@Linux.IT>
   9 #
  10 # This program is free software; you can redistribute it and/or modify it
  11 # under the terms of the GNU General Public License as published by the
  12 # Free Software Foundation version 2 of the License.
  13
  14 # debug, if UDEV_LOG=<debug>
  15 if [ -n "$UDEV_LOG" ]; then
  16         if [ "$UDEV_LOG" -ge 7 ]; then
  17                 set -x
  18         fi
  19 fi
  20
  21 RULES_FILE="/etc/udev/rules.d/70-persistent-cd.rules"
  22
  23 . /lib/udev/rule_generator.functions
  24
  25 find_next_available() {
  26         raw_find_next_available "$(find_all_rules 'SYMLINK\+=' "$1")"
  27 }
  28
  29 write_rule() {
  30         local match="$1"
  31         local link="$2"
  32         local comment="$3"
  33
  34         {
  35         if [ "$PRINT_HEADER" ]; then
  36                 PRINT_HEADER=
  37                 echo "# This file was automatically generated by the $0"
  38                 echo "# program, run by the cd-aliases-generator.rules rules file."
  39                 echo "#"
  40                 echo "# You can modify it, as long as you keep each rule on a single"
  41                 echo "# line, and set the \$GENERATED variable."
  42                 echo ""
  43         fi
  44
  45         [ "$comment" ] && echo "# $comment"
  46         echo "$match, SYMLINK+=\"$link\", ENV{GENERATED}=\"1\""
  47         } >> $RULES_FILE
  48         SYMLINKS="$SYMLINKS $link"
  49 }
  50
  51 if [ -z "$DEVPATH" ]; then
  52         echo "Missing \$DEVPATH." >&2
  53         exit 1
  54 fi
  55 if [ -z "$ID_CDROM" ]; then
  56         echo "$DEVPATH is not a CD reader." >&2
  57         exit 1
  58 fi
  59
  60 if [ "$1" ]; then
  61         METHOD="$1"
  62 else
  63         METHOD='by-path'
  64 fi
  65
  66 case "$METHOD" in
  67         by-path)
  68         if [ -z "$ID_PATH" ]; then
  69                 echo "$DEVPATH not supported by path_id. by-id may work." >&2
  70                 exit 1
  71         fi
  72         RULE="ENV{ID_PATH}==\"$ID_PATH\""
  73         ;;
  74
  75         by-id)
  76         if [ "$ID_SERIAL" ]; then
  77                 RULE="ENV{ID_SERIAL}==\"$ID_SERIAL\""
  78         elif [ "$ID_MODEL" -a "$ID_REVISION" ]; then
  79                 RULE="ENV{ID_MODEL}==\"$ID_MODEL\", ENV{ID_REVISION}==\"$ID_REVISION\""
  80         else
  81                 echo "$DEVPATH not supported by ata_id. by-path may work." >&2
  82                 exit 1
  83         fi
  84         ;;
  85
  86         *)
  87         echo "Invalid argument (must be either by-path or by-id)." >&2
  88         exit 1
  89         ;;
  90 esac
  91
  92 # Prevent concurrent processes from modifying the file at the same time.
  93 lock_rules_file
  94
  95 # Check if the rules file is writeable.
  96 choose_rules_file
  97
  98 link_num=$(find_next_available 'cdrom[0-9]*')
  99
 100 match="ENV{ID_CDROM}==\"?*\", $RULE"
 101
 102 comment="$ID_MODEL ($ID_PATH)"
 103
 104         write_rule "$match" "cdrom$link_num" "$comment"
 105 [ "$ID_CDROM_CD_R" -o "$ID_CDROM_CD_RW" ] && \
 106         write_rule "$match" "cdrw$link_num"
 107 [ "$ID_CDROM_DVD" ] && \
 108         write_rule "$match" "dvd$link_num"
 109 [ "$ID_CDROM_DVD_R" -o "$ID_CDROM_DVD_RW" -o "$ID_CDROM_DVD_RAM" ] && \
 110         write_rule "$match" "dvdrw$link_num"
 111
 112 unlock_rules_file
 113
 114 echo $SYMLINKS
 115
 116 exit 0
 117