man.bsd.lv manual page server

DESCRIPTION

The calls that take and/or return a variable use a pointer to an int variable for this purpose; others use a pointer to an struct pnviocdesc descriptor, which contains a variable and two counted strings. The first string comprises the fields pnv_namelen (an int) and pnv_name (a char *), giving the name of a field. The second string comprises the fields pnv_buflen and pnv_buf, used analogously. These two counted strings work in a “value-result” fashion. At entry to the ioctl, the counts are expected to reflect the buffer size; on return, the counts are updated to reflect the buffer contents.

The following ioctls are supported:

PNVIOCGETNEXTNAME

Takes a variable name and returns the name of the following variable. If a NULL is passed as the variable name, the first variable name will be returned. If the last variable is given as an argument, the ioctl will return EINVAL.

PNVIOCGET

Fills in the value of the named property for the given variable. If no such property is associated with that variable, the value length is set to -1. If the named property exists but has no value, the value length is set to 0.

PNVIOCSET

Writes the given value under the given name.

PNVIOCGETNUMGE

Returns the number of variables in the Global Environment Area.