Commands Reference, Volume 1

cdcheck Command

Purpose

Asks cdromd daemon information about a device.

Syntax

cdcheck { -a | -m | -u | -e } [ -q ] [ -h | -? ] DeviceName

Description

The cdcheck command sends an appropriate command to the cdromd daemon to get information on a media or a device depending on the flag used.

The cdcheck command returns a zero (True) exit value and prints a message on stdout if the specified condition is true. Otherwise, the cdcheck command returns a nonzero (False) exit value and prints an error message on stderr.

To check if a device is managed by cdromd daemon, use the cdcheck command with the -a flag. If the cdromd daemon is running and the specified device is in its device list, the cdcheck -a command will return with a zero (True) exit value after printing the following message on stdout:

       cd<x> is managed by cdromd.

Note

An exit value of zero (True) with the -a flag means that a media will be automatically mounted when it is inserted. It does not mean that a media is currently mounted.

To check if a media is present and was mounted by cdromd daemon, use the cdcheck command with the -m flag. When a media is inserted in a drive, it can take several seconds or tens of seconds before it become ready and mounted. The cdcheck -m command waits until the end of the mount operation by the cdromd daemon. If this operation is successfull, the cdcheck -m command returns with a zero (True) exit value after printing the mount point on stdout.

Note

If the media is damaged and can't be mounted by the cdromd daemon, the cdcheck -m command returns a nonzero (False) exit value and prints an error message on stderr.

To check if a media is present but was unmounted by the cdumount command, use the cdcheck command with the -u flag. If the cdromd daemon is running and the specified device is in in unmounted state, the cdcheck -u command will return with a zero (True) exit value after printing the following message on stdout:

       cd<x> is not mounted.

To check that there is no media present in the specified device, use the cdcheck command with the -e flag. If the cdromd daemon is running and there is no media present in the drive, the cdcheck -e command will return with a zero (True) exit value after printing the following message on stdout:

       No media present in cd<x>.

When using cdcheck in shell scripts, the -q flag can be added to the cdcheck command so that no messages are printed on stdout and stderr. The only exception is the cdcheck command with the -m flag, which always prints the mount point on stdout so that the shell script can get this mount point.

Flags

-a	Checks if a device is managed by cdromd.
-e	Checks if a media has been ejected from a device.
-h or -?	Displays the command usage message.
-m	Checks if a media is mounted on a device.
-q	Specifies silent mode: Doesn't print any information or error message. Note If -q is used with the -m flag, the mount point will be printed to stdout.
-u	Checks if a media is not mounted on a device.
DeviceName	Specifies the name of the device.

Exit Status

This command returns the following exit values:

0: answer = yes.
>0: answer = no or error.

Examples

To ask cdromd if cd0 is managed enter:
```
cdcheck -a cd0
```
To ask cdromd if a media is mounted on cd1 without any printed error messages, enter:
```
cdcheck -m -q cd1
```
To ask cdromd if a media is not mounted on cd1 enter:
```
      cdcheck -u cd1
```
To ask cdromd if a media is not present on cd0 enter:
```
cdcheck -e cd0
```

Shell script example:

DEVICE=$1

if [ cdcheck -a -q "$DEVICE" ]; then
    AUTO_MOUNT="ON"
else
    AUTO_MOUNT="OFF"
fi

# Other initializations
# ...

if [ "$AUTO_MOUNT" = "ON" ]; then
    MOUNT_POINT=`cdcheck -m -q $DEVICE`
else
    MOUNT_POINT="/tmp/MyProg_$$"
    mount -rv cdrfs $DEVICE $MOUNT_POINT
fi
if [ $? -ne 0 ]; then
    echo "mount $DEVICE failed"
    exit 1
fi

# Now extract data from $MOUNT_POINT...
# ...


# End of processing. Umount the media
if [ "$AUTO_MOUNT" = "ON" ]; then
    cdeject -q $DEVICE
else
    unmount $DEVICE
fi
if [ $? -ne 0 ]; then
    echo "unmount $DEVICE failed"
    exit 1
fi

Related Information

The cdeject command, cdmount command, cdromd daemon, cdumount command, cdutil command.

The cdromd.conf file format.