plist.h File Reference

Linked List for maintaining process id - command line pairs. More...

#include <sys/types.h>

Go to the source code of this file.

Functions
int	insertElement (pid_t pid, const char *commandLine)
	Inserts a new pid-command line pair into the linked list. More...
int	removeElement (pid_t pid, char *commandLineBuffer, size_t bufferSize)
	Remove a specific pid-command line pair from the linked list. More...
void	walkList (int(*callback)(pid_t, const char *))
	Invokes a callback function on each element in the list. More...

Detailed Description

Linked List for maintaining process id - command line pairs.

This implementation is not thread safe.

Function Documentation

insertElement()

int insertElement	(	pid_t	pid,
		const char *	commandLine
	)

Inserts a new pid-command line pair into the linked list.

During the insert operation, the passed commandLine is copied to an internally allocated buffer. The caller may free or otherwise reuse the memory occupied by commandLine after return from insertElement.

Parameters

pid	The process id of the pair that is to be inserted.
commandLine	The commandLine corresponding to the process with id pid.

Returns

pid on success, negative value on error

Return values

pid	success
-1	a pair with the given pid already exists
-2	insufficient memory to complete the operation

removeElement()

int removeElement	(	pid_t	pid,
		char *	commandLineBuffer,
		size_t	bufferSize
	)

Remove a specific pid-command line pair from the linked list.

The linked list is searched for a pair with the given pid. If such a pair is found, the '\0'-terminated command line is copied to the buffer provided by the caller. If the length of the command line exceeds the size of the buffer, only the first (buffersize-1) characters of the command line are copied to the buffer and terminated with the '\0' character. Upon completion, removeElement deallocates all resources that were occupied by the removed pair.

Parameters

pid	The process id of the pair that is to be removed.
commandLineBuffer	A buffer provided by the caller that the '\0'-terminated commandline is written to.
bufferSize	The size of commandLineBuffer.

Returns

actual length of the command line on success, negative value on error.

Return values

>0	success, actual length of the command line
-1	a pair with the given pid does not exist

walkList()

void walkList

(

int(*)(pid_t, const char *)

callback

)

Invokes a callback function on each element in the list.

The callback function is passed the pid-command line pair for the current
list element. The callback function shall return 0 to request further
processing of the list. Any other return value will cause the early
termination of the list walk. The callback function must not modify the
process list.

Parameters

callback

Pointer to the function to be invoked for each list element.