Advanced Programming in the UNIX® Environment

ptg10805159

Section 8.14 Process Accounting 271

FreeBSD Linux Mac OS X Solaris

ac_flag Description 8.0 3.2.0 10.6.8 10

AFORK process is the result offork,but never calledexec ••••

ASU process used superuser privileges •••

ACORE process dumped core•••

AXSIG process was killed by a signal •••

AEXPND expanded accounting entry •

ANVER new recordformat •

Figure 8.26Values forac_flagfrom accounting record

execs B, then Bexecs C, and Cexits—only a single accounting record is written.

The command name in the recordcorresponds to program C, but the CPU times, for

example, arethe sum for programs A, B, and C.

Example

To have some accounting data to examine, we’ll create a test program to implement the

diagram shown in Figure8.27.

sleep( 2 )

exit( 2 )

sleep( 4 )

abort()

sleep( 8 )

exit( 0 )

sleep( 6 )

kill()

parent

first child

second child

thirdchild

fourth child

/bin/dd

fork

fork

fork

fork

execl

Figure 8.27 Process structurefor accounting example

The source for the test program is shown in Figure8.28. It callsforkfour times. Each

child does something different and then terminates.

#include "apue.h"

int

main(void)

{

pid_t pid;

if ((pid = fork()) < 0)

err_sys("fork error");