Re: Getting a fully-qualified path from a PID

From: Dan Nelson (dnelson_at_allantgroup.com)
Date: 07/21/04

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    Date: Wed, 21 Jul 2004 10:12:20 -0500
To: Joe Marcus Clarke <marcus@marcuscom.com>

    In the last episode (Jul 20), Joe Marcus Clarke said:
    > What is the canonical way for a userland application to get the
    > fully-qualified path of an executable from its running PID? I know I
    > can do a readlink(2) on /proc/pid/file, but procfs is deprecated on
    > 5.X, correct? Is there a more appropriate way to do this? Thanks.

    realpath(argv[0]) works for commands not run from $PATH. Commands found
    through a PATH earch will just have the basename in argv[0] so you
    would have to check each PATH element until you found it. Note that
    /proc/pid/file won't work if vn_fullpath() fails (say the orignal file
    has been unlinked, or the filename has expired from the kernel's
    cache).

    If you are examining another process, you can use the kvm_getargv() and
    kvm_getenvv() functions to fetch argv[0] and PATH out of the target
    process. 

    -- 
	Dan Nelson
	dnelson@allantgroup.com
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