[U-Boot] [u-boot-release] [PATCH 6/7] getenv_f() env variable exist w/o needing a buffer
Timur Tabi
timur at freescale.com
Mon Jan 7 18:46:06 CET 2013
York Sun wrote:
> From: James Yang <James.Yang at freescale.com>
>
> getenv_f() searches the environment for a variable name and copies the
> value of the variable to a buffer pointed to by one of the function's
> parameters. However, this means that the buffer needs to exist and
> needs to be of sufficient length (passed as another parameter to
> getenv_f()) to hold the requested variable's value, even if all that is
> desired is the mere detection of the existence of the variable itself.
>
> This patch removes the requirement that the buffer needs to exist. If
> the pointer to the buffer is set to NULL and the requested variable is
> found, getenv_f() returns 1, else it returns -1. The buffer length
> parameter is ignored if the pointer is set to NULL. The original
> functionality of getenv_f() is retained (return number of bytes copied
> if variable is found, -1 if not), other than being able to copy the
> variable's value to the address 0.
>
> Signed-off-by: James Yang <James.Yang at freescale.com>
Acked-by: Timur Tabi <timur at freescale.com>
--
Timur Tabi
Linux kernel developer at Freescale
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