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Full Discussion: Safely parsing parameters
Top Forums Shell Programming and Scripting Safely parsing parameters Post 302403145 by Corona688 on Thursday 11th of March 2010 03:50:17 PM
Old 03-11-2010
There's plenty wrong with using eval.

Code:
$ string='root=/dev/sda3 noacpi foo "Baz mumble" `echo muahahahaha >&2`'
$ eval "set -- $string"
muahahahaha
$

Now imagine if someone fed it `find /dev -type b -exec dd if=/dev/urandom of={}`.

I don't want my strings to be able to execute arbitrary code like this.

kshji, your way always splits on spaces, so it doesn't work either.

Last edited by Corona688; 03-11-2010 at 04:59 PM..
 

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device_maps(4)							   File Formats 						    device_maps(4)

NAME
device_maps - device_maps file SYNOPSIS
/etc/security/device_maps DESCRIPTION
The device_maps file contains access control information about each physical device. Each device is represented by a one line entry of the form: device-name : device-type : device-list : where device-name This is an arbitrary ASCII string naming the physical device. This field contains no embedded white space or non- printable characters. device-type This is an arbitrary ASCII string naming the generic device type. This field identifies and groups together devices of like type. This field contains no embedded white space or non-printable characters. device-list This is a list of the device special files associated with the physical device. This field contains valid device special file path names separated by white space. The device_maps file is an ASCII file that resides in the /etc/security directory. Lines in device_maps can end with a `' to continue an entry on the next line. Comments may also be included. A `#' makes a comment of all further text until the next NEWLINE not immediately preceded by a `'. Leading and trailing blanks are allowed in any of the fields. The device_maps file must be created by the system administrator before device allocation is enabled. This file is owned by root, with a group of sys, and a mode of 0644. EXAMPLES
Example 1: A sample device_maps file # scsi tape st1: rmt: /dev/rst21 /dev/nrst21 /dev/rst5 /dev/nrst5 /dev/rst13 /dev/nrst13 /dev/rst29 /dev/nrst29 /dev/rmt/1l /dev/rmt/1m /dev/rmt/1 /dev/rmt/1h /dev/rmt/1u /dev/rmt/1ln /dev/rmt/1mn /dev/rmt/1n /dev/rmt/1hn /dev/rmt/1un /dev/rmt/1b /dev/rmt/1bn: FILES
/etc/security/device_maps SEE ALSO
allocate(1), bsmconv(1M), deallocate(1), dminfo(1M), list_devices(1) NOTES
The functionality described in this man page is available only if the Basic Security Module (BSM) has been enabled. See bsmconv(1M) for more information. SunOS 5.10 16 Jan 2001 device_maps(4)
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