/var/log/cups $ sudo strace -f  -e open -p 3898                                                                                          
Process 3898 attached - interrupt to quit                                                                                                
open("/etc/group", O_RDONLY|O_CLOEXEC)  = 12                                                                                             
open("/etc/group", O_RDONLY|O_CLOEXEC)  = 12                                                                                             
open("/etc/group", O_RDONLY|O_CLOEXEC)  = 12                                                                                             
open("/etc/group", O_RDONLY|O_CLOEXEC)  = 12                                                                                             
open("/etc/group", O_RDONLY|O_CLOEXEC)  = 12                                                                                             
open("/etc/group", O_RDONLY|O_CLOEXEC)  = 12                                                                                             
open("/etc/group", O_RDONLY|O_CLOEXEC)  = 12                                                                                             
open("/etc/cups/ppd/HP_Color_LaserJet_3600.ppd", O_RDONLY) = 12                                                                          
open("/etc/cups/ppd/HP_Color_LaserJet_3600.ppd", O_RDONLY) = 12                                                                          
open("/etc/group", O_RDONLY|O_CLOEXEC)  = 13                                                                                             
open("/etc/cups/ppd/PDF.ppd", O_RDONLY) = 12                                                                                             
open("/etc/cups/ppd/PDF.ppd", O_RDONLY) = 12                                                                                             
open("/etc/group", O_RDONLY|O_CLOEXEC)  = 13                                                                                             
open("/var/spool/cups/00000005", O_WRONLY|O_CREAT|O_TRUNC, 0640) = 12                                                                    
open("/var/spool/cups/00000005", O_RDONLY) = 12                                                                                          
open("/var/spool/cups/00000005", O_RDONLY) = 12                                                                                          
open("/etc/cups/subscriptions.conf", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 12                                                                
open("/var/spool/cups/c00127", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 12                                                                      
open("/etc/cups/subscriptions.conf", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 12                                                                
Process 27822 attached (waiting for parent)                                                                                              
Process 27822 resumed (parent 3898 ready)                                                                                                
[pid 27822] open("/dev/null", O_RDONLY) = 0                                                                                              
Process 27822 detached                                                                                                                   
--- SIGCHLD (Child exited) @ 0 (0) ---                                                                                                   
Process 27823 attached (waiting for parent)
Process 27823 resumed (parent 3898 ready)
Process 27823 detached
--- SIGCHLD (Child exited) @ 0 (0) ---
Process 27824 attached (waiting for parent)
Process 27824 resumed (parent 3898 ready)
Process 27824 detached
--- SIGCHLD (Child exited) @ 0 (0) ---
Process 27825 attached (waiting for parent)
Process 27825 resumed (parent 3898 ready)
[pid 27825] open("/dev/null", O_WRONLY) = 1
Process 27825 detached
--- SIGCHLD (Child exited) @ 0 (0) ---
open("/etc/cups/subscriptions.conf", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 12
open("/etc/group", O_RDONLY|O_CLOEXEC)  = 12
open("/etc/group", O_RDONLY|O_CLOEXEC)  = 12
open("/etc/group", O_RDONLY|O_CLOEXEC)  = 12
open("/etc/group", O_RDONLY|O_CLOEXEC)  = 12
open("/etc/cups/subscriptions.conf", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 12
open("/var/spool/cups/c00127", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 12
open("/var/spool/cups/c00127", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 12
open("/etc/cups/subscriptions.conf", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 12
open("/etc/group", O_RDONLY|O_CLOEXEC)  = 12
open("/etc/passwd", O_RDONLY|O_CLOEXEC) = 12
open("/etc/group", O_RDONLY|O_CLOEXEC)  = 12
open("/etc/group", O_RDONLY|O_CLOEXEC)  = 12
open("/etc/passwd", O_RDONLY|O_CLOEXEC) = 12
open("/etc/group", O_RDONLY|O_CLOEXEC)  = 12
open("/etc/passwd", O_RDONLY|O_CLOEXEC) = 12
open("/etc/group", O_RDONLY|O_CLOEXEC)  = 12
open("/etc/passwd", O_RDONLY|O_CLOEXEC) = 12
open("/etc/group", O_RDONLY|O_CLOEXEC)  = 12