PREAD(3PROC) Process Control Library Functions PREAD(3PROC)

NAME


Pread, Pread_string - read data from a process

LIBRARY


Process Control Library (libproc, -lproc)

SYNOPSIS


#include <libproc.h>

ssize_t
Pread(struct ps_prochandle *P, void *buf, size_t nbytes,
uintptr_t address);

ssize_t
Pread_string(struct ps_prochandle *P, char *buf, size_t nbytes,
uintptr_t address);

DESCRIPTION


The Pread() function reads data from the process handle P starting at
address in the address space of the process and reads at most nbytes of
data into buf and is logically analogous to the pread(2) function.

For live processes, this function is equivalent to reading from the /proc
file system as file for the process. For core files and file handles, it
reads and writes from the logical address space and not the corresponding
offset of the file itself. For example, a core file contains a sparse
representation of the address space of a crashed process and unmapped
regions are not present in the file. However, address still refers to the
virtual addresses that were present at run-time and not those in the core
file.

The Pread_string() function is similar to the Pread() function, except that
it attempts to interpret address as a null terminated character string and
will stop reading characters into buf if either nbytes has been read or a
null terminator is encountered. The resulting data in buf will always be
null terminated, even if no null terminator was found in the first nbytes
of data.

RETURN VALUES


Upon successful completion, the Pread() and Pread_string() functions return
a non-negative integer indicating the number of bytes actually read.
Otherwise, the functions return -1 and set errno to indicate the error.

ERRORS


For a full list of possible errors also see the DIAGNOSTICS section in
proc(4) and the ERRORS section in pread(2).

INTERFACE STABILITY


Uncommitted

MT-LEVEL
See LOCKING in libproc(3LIB).

SEE ALSO


pread(2), libproc(3LIB), proc(4)

illumos May 11, 2016 illumos