PS(1) PS(1) NAME ps - process status SYNOPSIS ps [ acegklnstuvwxU# ] DESCRIPTION _P_s prints information about processes. Normally, only your processes are candidates to be printed by _p_s_; specifying a causes other users’ processes to be candidates to be printed; specifying x includes pro‐ cesses without control terminals in the candidate pool. All output formats include, for each process, the process id PID, con‐ trol terminal of the process TT, cpu time used by the process TIME (this includes both user and system time), the state STAT of the pro‐ cess, and an indication of the COMMAND which is running. The state is given by a sequence of four letters, e.g. ‘‘RWNA’’. The first letter indicates the runnability of the process: R for runnable processes, T for stopped processes, P for processes in page wait, D for those in disk (or other short term) waits, S for those sleeping for less than about 20 seconds, and I for idle (sleeping longer than about 20 sec‐ onds) processes. The second letter indicates whether a process is swapped out, showing W if it is, or a blank if it is loaded (in-core); a process which has specified a soft limit on memory requirements and which is exceeding that limit shows >; such a process is (necessarily) not swapped. The third letter indicates whether a process is running with altered CPU scheduling priority (nice); if the process priority is reduced, an N is shown, if the process priority has been artificially raised then a ‘<’ is shown; processes running without special treatment have just a blank. The final letter indicates any special treatment of the process for virtual memory replacement; the letters correspond to options to the _v_a_d_v_i_s_e(2) call; currently the possibilities are A standing for VA_ANOM, S for VA_SEQL and blank for VA_NORM; an A typi‐ cally represents a _l_i_s_p(1) in garbage collection, S is typical of large image processing programs which are using virtual memory to sequen‐ tially address voluminous data. Here are the options: a asks for information about all processes with terminals (ordinar‐ ily only one’s own processes are displayed). c prints the command name, as stored internally in the system for purposes of accounting, rather than the command arguments, which are kept in the process’ address space. This is more reliable, if less informative, since the process is free to destroy the latter information. e Asks for the environment to be printed as well as the arguments to the command. g Asks for all processes. Without this option, _p_s only prints ‘‘interesting’’ processes. Processes are deemed to be uninterest‐ ing if they are process group leaders. This normally eliminates top-level command interpreters and processes waiting for users to login on free terminals. k causes the file _/_v_m_c_o_r_e is used in place of _/_d_e_v_/_k_m_e_m and _/_d_e_v_/_m_e_m_. This is used for postmortem system debugging. l asks for a long listing, with fields PPID, CP, PRI, NI, ADDR, SIZE, RSS and WCHAN as described below. n Asks for numerical output. In a long listing, the WCHAN field is printed numerically rather than symbolically, or, in a user list‐ ing, the USER field is replaced by a UID field. s Adds the size SSIZ of the kernel stack of each process (for use by system maintainers) to the basic output format. t_x restricts output to processes whose controlling tty is _x (which should be specified as printed by _p_s_, e.g. _t_3 for tty3, _t_c_o for console, _t_d_0 for ttyd0, _t_? for processes with no tty, _t for pro‐ cesses at the current tty, etc). This option must be the last one given. u A user oriented output is produced. This includes fields USER, %CPU, NICE, SIZE, and RSS as described below. v A version of the output containing virtual memory statistics is output. This includes fields RE, SL, PAGEIN, SIZE, RSS, LIM, TSIZ, TRS, %CPU and %MEM, described below. w Use a wide output format (132 columns rather than 80); if repeated, e.g. ww, use arbitrarily wide output. This information is used to decide how much of long commands to print. x asks even about processes with no terminal. U causes ps to update a private database where is keeps system information. Thus ‘‘ps U’’ should be included in the /etc/rc file. # A process number may be given, (indicated here by #), in which case the output is restricted to that process. This option must also be last. A second argument is taken to be the file containing the system’s namelist. Otherwise, /vmunix is used. A third argument tells _p_s where to look for _c_o_r_e if the k option is given, instead of /vmcore. If a fourth argument is given, it is taken to be the name of a swap file to use instead of the default /dev/drum. Fields which are not common to all output formats: USER name of the owner of the process %CPU cpu utilization of the process; this is a decaying average over up to a minute of previous (real) time. Since the time base over which this is computed varies (since processes may be very young) it is possible for the sum of all %CPU fields to exceed 100%. NICE (or NI) process scheduling increment (see _s_e_t_p_r_i_o_r_i_t_y(2)) SIZE virtual size of the process (in 1024 byte units) RSS real memory (resident set) size of the process (in 1024 byte units) LIM soft limit on memory used, specified via a call to _s_e_t_r_‐ _l_i_m_i_t(2); if no limit has been specified then shown as _x_x TSIZ size of text (shared program) image TRS size of resident (real memory) set of text %MEM percentage of real memory used by this process. RE residency time of the process (seconds in core) SL sleep time of the process (seconds blocked) PAGEIN number of disk i/o’s resulting from references by the process to pages not loaded in core. UID numerical user-id of process owner PPID numerical id of parent of process CP short-term cpu utilization factor (used in scheduling) PRI process priority (non-positive when in non-interruptible wait) ADDR swap address of the process WCHAN event on which process is waiting (an address in the system). A symbol is chosen that classifies the address, unless numer‐ ical output is requested (see the n flag). In this case, the initial part of the address is trimmed off and is printed hexadecimally, e.g., 0x80004000 prints as 4000. F flags associated with process as in <_s_y_s_/_p_r_o_c_._h>: SLOAD 000001 in core SSYS 000002 swapper or pager process SLOCK 000004 process being swapped out SSWAP 000008 save area flag STRC 000010 process is being traced SWTED 000020 another tracing flag SULOCK 000040 user settable lock in core SPAGE 000080 process in page wait state SKEEP 000100 another flag to prevent swap out SDLYU 000200 delayed unlock of pages SWEXIT 000400 working on exiting SPHYSIO 000800 doing physical i/o (bio.c) SVFORK 001000 process resulted from vfork() SVFDONE 002000 another vfork flag SNOVM 004000 no vm, parent in a vfork() SPAGI 008000 init data space on demand from inode SANOM 010000 system detected anomalous vm behavior SUANOM 020000 user warned of anomalous vm behavior STIMO 040000 timing out during sleep SDETACH 080000 detached inherited by init SOUSIG 100000 using old signal mechanism A process that has exited and has a parent that has not yet waited for the process is marked ; a process which is blocked trying to exit is marked ; _P_s makes an educated guess as to the file name and arguments given when the process was created by examining mem‐ ory or the swap area. The method is inherently somewhat unreliable and in any event a process is entitled to destroy this information, so the names cannot be counted on too much. FILES /vmunix system namelist /dev/kmem kernel memory /dev/drum swap device /vmcore core file /dev searched to find swap device and tty names /etc/psdatabase system namelist, device, and wait channel information SEE ALSO kill(1), w(1) BUGS Things can change while _p_s is running; the picture it gives is only a close approximation to reality. 4th Berkeley Distribution May 12, 1986 PS(1)