oracular (3) nbdkit_absolute_path.3.gz

Provided by: nbdkit-plugin-dev_1.40.4-1ubuntu1_amd64 bug

NAME
       nbdkit_realpath, nbdkit_absolute_path - convert relative to absolute paths for nbdkit


SYNOPSIS
        #include <nbdkit-plugin.h>

        char *nbdkit_realpath (const char *filename);
        char *nbdkit_absolute_path (const char *filename);


DESCRIPTION
       nbdkit(1) usually (not always) changes directory to / before it starts serving connections.  This means
       that any relative paths passed during configuration will not work when the server is running.  In a naive
       implementation of a plugin, a configuration like

        nbdkit plugin file=disk.img

       might attempt to open /disk.img instead of the file in the user's current directory.

       To avoid this problem, you can:

       •   convert relative paths to absolute paths using one of the functions described here, or

       •   open the file at configure time and store the file descriptor.

   nbdkit_realpath
       The utility function "nbdkit_realpath" converts any path to an absolute path, resolving symlinks.  Under
       the hood it uses the realpath(3) function, and thus it fails if the path does not exist, or it is not
       possible to access components of the path.

       This function works only when used in the ".config", ".config_complete" and ".get_ready" callbacks.

   nbdkit_absolute_path
       The utility function "nbdkit_absolute_path" converts any path to an absolute path: if it is relative,
       then all this function does is prepend the current working directory to the path, with no extra checks.

       Unlike "nbdkit_realpath", this function does not check that the file exists.

       This function works only when used in the ".config", ".config_complete" and ".get_ready" callbacks.


RETURN VALUE
       On success these functions return a newly allocated string.  The returned string must be freed by the
       caller.

       On error these call nbdkit_error(3) and return "NULL".


LANGUAGE BINDINGS
       In nbdkit-ocaml-plugin(3):

        NBDKit.realpath : string -> string


HISTORY
       "nbdkit_absolute_path" was present in nbdkit 0.1.0.

       "nbdkit_realpath" was added in nbdkit 1.4.


SEE ALSO
       nbdkit(1), nbdkit-plugin(3), nbdkit-filter(3).


AUTHORS
       Richard W.M. Jones


       Copyright Red Hat


LICENSE
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       that the following conditions are met:

       •   Redistributions of source code must retain the above copyright notice, this list of conditions and
           the following disclaimer.

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           the following disclaimer in the documentation and/or other materials provided with the distribution.

       •   Neither the name of Red Hat nor the names of its contributors may be used to endorse or promote
           products derived from this software without specific prior written permission.

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