1 #!/bin/sh

     2 

     3 # This script starts an instance of Xvfb, the "fake" X server, runs a command

     4 # with that server available, and kills the X server when done.  The return

     5 # value of the command becomes the return value of this script.

     6 #

     7 # If anyone is using this to build a Debian package, make sure the package

     8 # Build-Depends on xvfb and xauth.

     9 

    10 set -e

    11 

    12 PROGNAME=xvfb-run

    13 SERVERNUM=99

    14 AUTHFILE=

    15 ERRORFILE=/dev/null

    16 XVFBARGS="-screen 0 640x480x8"

    17 LISTENTCP="-nolisten tcp"

    18 XAUTHPROTO=.

    19 

    20 # Query the terminal to establish a default number of columns to use for

    21 # displaying messages to the user.  This is used only as a fallback in the event

    22 # the COLUMNS variable is not set.  ($COLUMNS can react to SIGWINCH while the

    23 # script is running, and this cannot, only being calculated once.)

    24 DEFCOLUMNS=$(stty size 2>/dev/null | awk '{print $2}') || true

    25 if ! expr "$DEFCOLUMNS" : "[[:digit:]]\+$" >/dev/null 2>&1; then

    26     DEFCOLUMNS=80

    27 fi

    28 

    29 # Display a message, wrapping lines at the terminal width.

    30 message () {

    31     echo "$PROGNAME: $*" | fmt -t -w ${COLUMNS:-$DEFCOLUMNS}

    32 }

    33 

    34 # Display an error message.

    35 error () {

    36     message "error: $*" >&2

    37 }

    38 

    39 # Display a usage message.

    40 usage () {

    41     if [ -n "$*" ]; then

    42         message "usage error: $*"

    43     fi

    44     cat <<EOF

    45 Usage: $PROGNAME [OPTION ...] COMMAND

    46 Run COMMAND (usually an X client) in a virtual X server environment.

    47 Options:

    48 -a        --auto-servernum          try to get a free server number, starting at

    49                                     --server-num

    50 -e FILE   --error-file=FILE         file used to store xauth errors and Xvfb

    51                                     output (default: $ERRORFILE)

    52 -f FILE   --auth-file=FILE          file used to store auth cookie

    53                                     (default: ./.Xauthority)

    54 -h        --help                    display this usage message and exit

    55 -n NUM    --server-num=NUM          server number to use (default: $SERVERNUM)

    56 -l        --listen-tcp              enable TCP port listening in the X server

    57 -p PROTO  --xauth-protocol=PROTO    X authority protocol name to use

    58                                     (default: xauth command's default)

    59 -s ARGS   --server-args=ARGS        arguments (other than server number and

    60                                     "-nolisten tcp") to pass to the Xvfb server

    61                                     (default: "$XVFBARGS")

    62 EOF

    63 }

    64 

    65 # Find a free server number by looking at .X*-lock files in /tmp.

    66 find_free_servernum() {

    67     # Sadly, the "local" keyword is not POSIX.  Leave the next line commented in

    68     # the hope Debian Policy eventually changes to allow it in /bin/sh scripts

    69     # anyway.

    70     #local i

    71 

    72     i=$SERVERNUM

    73     while [ -f /tmp/.X$i-lock ]; do

    74         i=$(($i + 1))

    75     done

    76     echo $i

    77 }

    78 

    79 # Clean up files

    80 clean_up() {

    81     if [ -e "$AUTHFILE" ]; then

    82         XAUTHORITY=$AUTHFILE xauth remove ":$SERVERNUM" >>"$ERRORFILE" 2>&1

    83     fi

    84     if [ -n "$XVFB_RUN_TMPDIR" ]; then

    85         if ! rm -r "$XVFB_RUN_TMPDIR"; then

    86             error "problem while cleaning up temporary directory"

    87             exit 5

    88         fi

    89         XVFB_RUN_TMPDIR=

    90     fi

    91     if [ -n "$XVFBPID" ]; then

    92         kill "$XVFBPID"

    93     fi

    94 }

    95 

    96 # Parse the command line.

    97 ARGS=$(getopt --options +ae:f:hn:lp:s:w: \

    98        --long auto-servernum,error-file:,auth-file:,help,server-num:,listen-tcp,xauth-protocol:,server-args:,wait: \

    99        --name "$PROGNAME" -- "$@")

   100 GETOPT_STATUS=$?

   101 

   102 if [ $GETOPT_STATUS -ne 0 ]; then

   103     error "internal error; getopt exited with status $GETOPT_STATUS"

   104     exit 6

   105 fi

   106 

   107 eval set -- "$ARGS"

   108 

   109 while :; do

   110     case "$1" in

   111         -a|--auto-servernum) SERVERNUM=$(find_free_servernum); AUTONUM="yes" ;;

   112         -e|--error-file) ERRORFILE="$2"; shift ;;

   113         -f|--auth-file) AUTHFILE="$2"; shift ;;

   114         -h|--help) SHOWHELP="yes" ;;

   115         -n|--server-num) SERVERNUM="$2"; shift ;;

   116         -l|--listen-tcp) LISTENTCP="" ;;

   117         -p|--xauth-protocol) XAUTHPROTO="$2"; shift ;;

   118         -s|--server-args) XVFBARGS="$2"; shift ;;

   119         -w|--wait) shift ;;

   120         --) shift; break ;;

   121         *) error "internal error; getopt permitted \"$1\" unexpectedly"

   122            exit 6

   123            ;;

   124     esac

   125     shift

   126 done

   127 

   128 if [ "$SHOWHELP" ]; then

   129     usage

   130     exit 0

   131 fi

   132 

   133 if [ -z "$*" ]; then

   134     usage "need a command to run" >&2

   135     exit 2

   136 fi

   137 

   138 if ! which xauth >/dev/null; then

   139     error "xauth command not found"

   140     exit 3

   141 fi

   142 

   143 # tidy up after ourselves

   144 trap clean_up EXIT TERM

   145 

   146 # If the user did not specify an X authorization file to use, set up a temporary

   147 # directory to house one.

   148 if [ -z "$AUTHFILE" ]; then

   149     XVFB_RUN_TMPDIR="$(mktemp -d -t $PROGNAME.XXXXXX)"

   150     # Create empty file to avoid xauth warning

   151     AUTHFILE=$(tempfile -n "$XVFB_RUN_TMPDIR/Xauthority")

   152 fi

   153 

   154 # Start Xvfb.

   155 MCOOKIE=$(mcookie)

   156 tries=10

   157 while [ $tries -gt 0 ]; do

   158     tries=$(( $tries - 1 ))

   159     XAUTHORITY=$AUTHFILE xauth source - << EOF >>"$ERRORFILE" 2>&1

   160 add :$SERVERNUM $XAUTHPROTO $MCOOKIE

   161 EOF

   162     # handle SIGUSR1 so Xvfb knows to send a signal when it's ready to accept

   163     # connections

   164     trap : USR1

   165     (trap '' USR1; XAUTHORITY=$AUTHFILE exec Xvfb ":$SERVERNUM" $XVFBARGS $LISTENTCP >>"$ERRORFILE" 2>&1) &

   166     XVFBPID=$!

   167 

   168     wait || :

   169     if kill -0 $XVFBPID 2>/dev/null; then

   170         break

   171     elif [ -n "$AUTONUM" ]; then

   172         # The display is in use so try another one (if '-a' was specified).

   173         SERVERNUM=$((SERVERNUM + 1))

   174         SERVERNUM=$(find_free_servernum)

   175         continue

   176     fi

   177     error "Xvfb failed to start" >&2

   178     XVFBPID=

   179     exit 1

   180 done

   181 

   182 # Start the command

   183 DISPLAY=:$SERVERNUM XAUTHORITY=$AUTHFILE "$@" 2>&1 &

   184 wait $!

   185 

   186 # vim:set ai et sts=4 sw=4 tw=80: