Linux Processes

Process Viewing

To display a sorted list of all processes real-time:

$ top

To display a nice process tree:

$ watch -n.5 pstree -p
                     |_ show PIDs (Process IDs)

Process Descriptions

Example output of pstree:

init-+-3*[agetty]   <- init (process control initialization) is the mother of all processes
                       agetty (alternative Linux teletypewriter) is the terminal emulator
     |-cardmgr      <- cardmgr (PCMCIA device manager) monitors for PCMCIA card insertion
                               and removal
     |-cron         <- daemon to execute scheduled commands
     |-devfsd       <- daemon for managing the Linux Device Filesystem (/dev)
     |-dhcpcd       <- Dynamic Host Configuration Protocol client daemon
     |-events/0-+-aio/0
     |          |-ata/0
     |          |-kblockd/0
     |          |-khelper
     |          `-2*[pdflush]
     |-gpm          <- general purpose mouse server
     |-kapmd
     |-khpsbpkt
     |-khubd
     |-kseriod
     |-ksoftirqd/0
     |-kswapd0
     |-login---bash  <- system session
     |-login---bash---make---make---gcc-+-as   <- some compilation is in progress
     |                                  `-cc1
     |-2*[pccardd]  <- PCMCIA related daemon
     |-syslog-ng    <- system logging utility
     `-vesafb       <- VESA framebuffer related

Process Monitoring

$ strace [command]