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 RULES_FILE="/etc/udev/rules.d/70-persistent-cd.rules"
  15
  16 . /lib/udev/rule_generator.functions
  17
  18 find_next_available() {
  19         raw_find_next_available "$(find_all_rules 'SYMLINK+=' $1)"
  20 }
  21
  22 write_rule() {
  23         local match="$1"
  24         local link="$2"
  25         local comment="$3"
  26
  27         {
  28         if [ "$PRINT_HEADER" ]; then
  29                 PRINT_HEADER=
  30                 echo "# This file was automatically generated by the $0"
  31                 echo "# program, probably run by the cd-aliases-generator.rules rules file."
  32                 echo "#"
  33                 echo "# You can modify it, as long as you keep each rule on a single line"
  34                 echo "# and set the \$GENERATED variable."
  35                 echo ""
  36         fi
  37
  38         [ "$comment" ] && echo "# $comment"
  39         echo "$match, SYMLINK+=\"$link\", ENV{GENERATED}=\"1\""
  40         } >> $RULES_FILE
  41         SYMLINKS="$SYMLINKS $link"
  42 }
  43
  44 if [ -z "$DEVPATH" ]; then
  45         echo "Missing \$DEVPATH." >&2
  46         exit 1
  47 fi
  48 if [ -z "$ID_CDROM" ]; then
  49         echo "$DEVPATH is not a CD reader." >&2
  50         exit 1
  51 fi
  52
  53 if [ "$1" ]; then
  54         METHOD="$1"
  55 else
  56         METHOD='by-path'
  57 fi
  58
  59 case "$METHOD" in
  60         by-path)
  61         if [ -z "$ID_PATH" ]; then
  62                 echo "$DEVPATH not supported by path_id. by-id may work." >&2
  63                 exit 1
  64         fi
  65         RULE="ENV{ID_PATH}==\"$ID_PATH\""
  66         ;;
  67
  68         by-id)
  69         if [ "$ID_SERIAL" ]; then
  70                 RULE="ENV{ID_SERIAL}==\"$ID_SERIAL\""
  71         elif [ "$ID_MODEL" -a "$ID_REVISION" ]; then
  72                 RULE="ENV{ID_MODEL}==\"$ID_MODEL\", ENV{ID_REVISION}==\"$ID_REVISION\""
  73         else
  74                 echo "$DEVPATH not supported by ata_id. by-path may work." >&2
  75                 exit 1
  76         fi
  77         ;;
  78
  79         *)
  80         echo "Invalid argument (must be either by-path or by-id)." >&2
  81         exit 1
  82         ;;
  83 esac
  84
  85 # Prevent concurrent processes from modifying the file at the same time.
  86 lock_rules_file
  87
  88 # Check if the rules file is writeable.
  89 choose_rules_file
  90
  91 link_num=$(find_next_available 'cdrom[0-9]*')
  92
  93 match="ENV{ID_CDROM}==\"?*\", $RULE"
  94
  95 comment="$ID_MODEL ($ID_PATH)"
  96
  97         write_rule "$match" "cdrom$link_num" "$comment"
  98 [ "$ID_CDROM_CD_R" -o "$ID_CDROM_CD_RW" ] && \
  99         write_rule "$match" "cdrw$link_num"
 100 [ "$ID_CDROM_DVD" ] && \
 101         write_rule "$match" "dvd$link_num"
 102 [ "$ID_CDROM_DVD_R" -o "$ID_CDROM_DVD_RW" -o "$ID_CDROM_DVD_RAM" ] && \
 103         write_rule "$match" "dvdrw$link_num"
 104
 105 unlock_rules_file
 106
 107 echo $SYMLINKS
 108
 109 exit 0
 110