NAME
mount_procfs —
mount the process file
system
SYNOPSIS
mount_procfs |
[-o
options] /proc
mount_point |
DESCRIPTION
The
mount_procfs command attaches an instance of the process
namespace to the global filesystem namespace. The conventional mount point is
/proc. The directory specified by
mount_point is converted to an absolute path before use.
This command is normally executed by
mount(8) at boot time.
The options are as follows:
-
-
- -o
nolinux
- Do not support nodes which are not part of the original
procfs implementation but have been added for compatibility with the Linux
procfs namespace. See FILES for more
information.
The root of the process filesystem contains an entry for each active process.
These processes are visible as a directory whose name is the process' pid. In
addition, the special entries
curproc and
self reference the current process. The
self symlink appears for compatibility with the Linux procfs
implementation.
Each directory contains several files.
-
-
- cmdline
- This file is readonly and returns null-terminated strings
corresponding to the process' command line arguments. For a system or
zombie process, this file contains only a string with the name of the
process.
-
-
- cwd
- A symbolic link that points to the current working
directory of the process. If the target process's current working
directory is not available or is not at or below the current process's
root directory, this link will point to “/”.
-
-
- fd/#
- File descriptors which can be accessed through the file
system. See fd(4) for more
information.
-
-
- file
- A reference to the vnode from which the process text was
read. This can be used to gain access to the process' symbol table, or to
start another copy of the process.
-
-
- map
- A map of the process' virtual memory.
-
-
- maps
- A map of the process' virtual memory in a form like the
proc filesystem as implemented in Linux. Note that the paths corresponding
to file backed mappings will not be present unless the kernel was built
with the NAMECACHE_ENTER_REVERSE option.
-
-
- mem
- The complete virtual memory image of the process. Only
those addresses which exist in the process can be accessed. Writes to this
file modify the process. Writes to the text segment normally remain
private to the process, since the text segment is mapped with MAP_PRIVATE;
however, this is not guaranteed.
-
-
- note
- Not implemented.
-
-
- notepg
- Not implemented.
-
-
- regs
- Allows read and write access to the process' register set.
This file contains a binary data structure
struct
regs
defined in <machine/reg.h>.
regs can only be written when the process is
stopped.
-
-
- fpregs
- The floating point registers as defined by
struct fpregs
in
<machine/reg.h>. fpregs is only
implemented on machines which have distinct general purpose and floating
point register sets.
-
-
- root
- A symbolic link that points to the root directory of the
process. If the target process's root directory is not available or is not
at or below the current process's root directory, this link will point to
“/”.
-
-
- status
- The process status. This file is readonly and returns a
single line containing multiple space-separated fields as follows:
- command name
- process id
- parent process id
- process group id
- session id
- major,minor
of the controlling terminal, or
-1,-1
if there
is no controlling terminal.
- a list of process flags:
ctty
if there is a controlling terminal,
sldr
if the process is a session leader,
noflags
if neither of the other two flags are
set.
- the process start time
in seconds and microseconds, comma separated.
- the user time in seconds
and microseconds, comma separated.
- the system time in
seconds and microseconds, comma separated.
- the wait channel
message
- the process credentials
consisting of the effective user id and the list of groups (whose
first member is the effective group id) all comma separated.
FILES
- /proc/#
-
- /proc/#/cmdline
-
- /proc/#/cwd
-
- /proc/#/exe
-
- /proc/#/file
-
- /proc/#/fpregs
-
- /proc/#/map
-
- /proc/#/maps
-
- /proc/#/mem
-
- /proc/#/note
-
- /proc/#/notepg
-
- /proc/#/regs
-
- /proc/#/root
-
- /proc/#/status
-
- /proc/curproc
-
- /proc/self
-
If the
linux mount option is used, the following files are
also available:
- /proc/#/stat
-
- /proc/cpuinfo
-
- /proc/devices
-
- /proc/meminfo
-
- /proc/mounts
-
- /proc/uptime
-
SEE ALSO
mount(2),
sigaction(2),
unmount(2)
HISTORY
The
mount_procfs utility first appeared in
4.4BSD.
BUGS
This filesystem may not be NFS-exported since most of the functionality of
procfs
requires that state be maintained.