pget(9) locate a process by number

SYNOPSIS

In sys/param.h In sys/proc.h Ft int Fn pget pid_t pid int flags struct proc **pp

DESCRIPTION

This function takes a Fa pid as its argument, which can be either a process or thread id, and fills a pointer to the Vt proc structure in Fa *pp . In the latter case, a process owning the specified thread is looked for. The operation is performed by invoking the pfind(9) function. The found process is returned locked. For the PGET_HOLD case, it is returned unlocked (but held). The Fn pget function can perform additional manipulations, depending on a Fa flags argument.

The Fa flags argument is the logical OR of some subset of:

PGET_HOLD
If set, the found process will be held and unlocked.
PGET_CANSEE
If set, the found process will be checked for its visibility. See p_cansee9.
PGET_CANDEBUG
If set, the found process will be checked for its debuggability. See p_candebug9.
PGET_ISCURRENT
If set, the found process will be checked that it matches the current process context.
PGET_NOTWEXIT
If set, the found process will be checked that it does not have the process flag P_WEXIT set.
PGET_NOTINEXEC
If set, the found process will be checked that it does not have the process flag P_INEXEC set.
PGET_NOTID
If set, Fa pid is not assumed as a thread id for values larger than PID_MAX
PGET_WANTREAD
If set, the found process will be checked that the caller may get a read access to its structure. A shorthand for (PGET_HOLD | PGET_CANDEBUG | PGET_NOTWEXIT )

RETURN VALUES

If the process is found in the specified way, then zero is returned, otherwise an appropriate error code is returned.