Gregory Nutt e4652bd3dc Squashed commit of the following:
fs: Add truncate() support for userfs
    fs/unionfs:  Add truncate() support to the unionfs
    fs/tmpfs:  Add ftruncate() support to tmpfs
    syscall/: Add system call support for ftruncate()
    net/route:  Adding ftruncate() support eliminates an issue in file-based routing table management.
    fs:  Add basic framework to support truncate() and ftruncate().  The infrastructure is complete.  Now, however, the actual implementation of ftruncate() will have to be done for each file system.
2018-01-03 16:03:56 -06:00
..
2018-01-03 16:03:56 -06:00

fs/procfs README
================

  This is a tiny procfs file system that allows read-only access to a few
  attributes of a task or thread.  This tiny procfs fs file system can be
  built into the system by enabling:

    CONFIG_FS_PROCFS=y

  It can then be mounted from the NSH command like like:

    nsh> mount -t procfs /proc

Example
=======

  NuttShell (NSH) NuttX-6.31
  nsh> mount -t procfs /proc

  nsh> ls /proc
  /proc:
   0/
   1/

  nsh> ls /proc/1
  /proc/1:
   status
   cmdline

  nsh> cat /proc/1/status
  Name:       init
  Type:       Task
  State:      Running
  Priority:   100
  Scheduler:  SCHED_FIFO
  SigMask:    00000000

  nsh> cat /proc/1/cmdline
  init

  nsh> sleep 100 &
  sleep [2:100]
  nsh> ls /proc
  ls /proc
  /proc:
   0/
   1/
   2/

  nsh> cat /proc/2/cmdline
  <pthread> 0x527420