THE VISOPSYS LIBRARY (Version 0.9)
(older version 0.85 is here)

The Visopsys library is a small set of general utility functions, often written to serve the needs of the Visopsys kernel, but which can also be used by user space programs and libraries.

The functions are defined in the header file <sys/vis.h> and the code is contained in libvis.a or libvis.so (link with ‘-lvis’). This code also requires a C library to link correctly (link with ‘-lc’).

int linkedListAddFront(linkedList *list, void *data)

Add the specified value ‘data’ to the front of linked list ‘list’.

int linkedListAddBack(linkedList *list, void *data)

Add the specified value ‘data’ to the back of linked list ‘list’.

int linkedListRemove(linkedList *list, void *data)

Remove the item with the specified value ‘data’ from the linked list ‘list’.

int linkedListClear(linkedList *list)

Remove everything from the linked list ‘list’.

void *linkedListIterStart(linkedList *list, linkedListItem **iter)

Starts an iteration through the linked list ‘list’, using the supplied iterator pointer ‘iter’. Returns the data value from the first item, if applicable.

void *linkedListIterNext(linkedList *list, linkedListItem **iter)

Returns the data value from the next item in the linked list ‘list’, if applicable. Uses the iterator pointer ‘iter’ previously initialized via a call to linkedListIterStart().

int variableListCreate(variableList *list)

Set up a new variable list structure.

int variableListCreateSystem(variableList *list)

Set up a new variable list structure, with memory owned by the kernel, rather than the calling process. Only useful for kernel code.

int variableListDestroy(variableList *list)

Deallocate a variable list structure previously allocated by a call to variableListCreate() or configurationReader()

const char *variableListGetVariable(variableList *list, int num)

Return a pointer to the name of the ‘num’th variable from the variable list ‘list’.

const char *variableListGet(variableList *list, const char *var)

Return a pointer to the value of the variable ‘var’ from the variable list ‘list’.

int variableListSet(variableList *list, const char *var, const char *value)

Set the value of the variable ‘var’ to the value ‘value’.

int variableListUnset(variableList *list, const char *var)

Remove the variable ‘var’ from the variable list ‘list’.

int variableListClear(variableList *list)

Remove all the variables from the variable list ‘list’.