chpst - runs a program with a changed process state

chpst [-vP012] [-u user] [-U user] [-e dir] [-/ root] [-n inc] [-l|-L lock] [-m bytes] [-d bytes] [-o n] [-p n] [-f bytes] [-c bytes] prog

prog consists of one or more arguments.

chpst changes the process state according to the given options, and runs prog.

-u user[:group] setuidgid. Set uid and gid to the user's uid and gid. If user is followed by a colon and a group, set the gid to group's gid instead of user's gid. If group consists of a colon-separated list of group names, chpst sets the group ids of all listed groups. All initial supplementary groups are removed.

-U user[:group] envuidgid. Set the environment variables $UID and $GID to the user's uid and gid. If user is followed by a colon and a group, set $GID to the group's gid instead of user's gid.

-e dir envdir. Set various environment variables as specified by files in the directory dir: If dir contains a file named k whose first line is v, chpst removes the environment variable k if it exists, and then adds the environment variable k with the value v. The name k must not contain =. Spaces and tabs at the end of v are removed, and nulls in v are changed to newlines. If the file k is empty (0 bytes long), chpst removes the environment variable k if it exists, without adding a new variable.

-/ root chroot. Change the root directory to root before starting prog.

-n inc nice. Add inc to the nice(2) value before starting prog. inc must be an integer, and may start with a minus or plus.

-l lock lock. Open the file lock for writing, and obtain an exclusive lock on it. lock will be created if it does not exist. If lock is locked by another process, wait until a new lock can be obtained.

-L lock The same as -l, but fail immediately if lock is locked by another process.

-m bytes limit memory. Limit the data segment, stack segment, locked physical pages, and total of all segment per process to bytes bytes each.

-d bytes limit data segment. Limit the data segment per process to bytes bytes.

-o n limit open files. Limit the number of open file descriptors per process to n.

-p n limit processes. Limit the number of processes per uid to n.

-f bytes limit output size. Limit the output file size to bytes bytes.

-c bytes limit core size. Limit the core file size to bytes bytes.

-v

verbose. Print verbose messages to standard error. This includes warnings about limits unsupported by the system.

-P

pgrphack. Run prog in a new process group.

-0

Close standard input before starting prog.

-1

Close standard output before starting prog.

-2

Close standard error before starting prog.

chpst exits 100 when called with wrong options. It prints an error message and exits 111 if it has trouble changing the process state. Otherwise its exit code is the same as that of prog.

If chpst is called as envdir, envuidgid, pgrphack, setlock, setuidgid, or softlimit, it emulates the functionality of these programs from the daemontools package respectively.

sv(8), runsv(8), setsid(2), runit(8), runit-init(8), runsvdir(8), runsvchdir(8)

http://smarden.org/runit/ http://cr.yp.to/daemontools.html

Gerrit Pape <pape@smarden.org>