#### 21.1.3 SVR4 Process Information

Many versions of SVR4 and compatible systems provide a facility called ‘`/proc`’ that can be used to examine the image of a running process using file-system subroutines. If gdb is configured for an operating system with this facility, the command `info proc` is available to report information about the process running your program, or about any process running on your system. `info proc` works only on SVR4 systems that include the `procfs` code. This includes, as of this writing, gnu/Linux, OSF/1 (Digital Unix), Solaris, Irix, and Unixware, but not HP-UX, for example.

`info proc`
`info proc` process-id
  Summarize available information about any running process. If a process ID is specified by process-id, display information about that process; otherwise display information about the program being debugged. The summary includes the debugged process ID, the command line used to invoke it, its current working directory, and its executable file's absolute file name.

  On some systems, process-id can be of the form ‘`[pid]/tid`’ which specifies a certain thread ID within a process. If the optional pid part is missing, it means a thread from the process being debugged (the leading ‘`/`’ still needs to be present, or else gdb will interpret the number as a process ID rather than a thread ID).

`info proc mappings`
  Report the memory address space ranges accessible in the program, with information on whether the process has read, write, or execute access rights to each range. On gnu/Linux systems, each memory range includes the object file which is mapped to that range, instead of the memory access rights to that range.
`info proc stat`
`info proc status`
  These subcommands are specific to gnu/Linux systems. They show the process-related information, including the user ID and group ID; how many threads are there in the process; its virtual memory usage; the signals that are pending, blocked, and ignored; its TTY; its consumption of system and user time; its stack size; its ‘`nice`’ value; etc. For more information, see the ‘`proc`’ man page (type `man 5 proc` from your shell prompt).
`info proc all`
  Show all the information about the process described under all of the above `info proc` subcommands.
`set procfs-trace`
  This command enables and disables tracing of `procfs` API calls.
`show procfs-trace`
  Show the current state of `procfs` API call tracing.
`set procfs-file` file
  Tell gdb to write `procfs` API trace to the named file. gdb appends the trace info to the previous contents of the file. The default is to display the trace on the standard output.
`show procfs-file`
  Show the file to which `procfs` API trace is written.
`proc-trace-entry`
`proc-trace-exit`
`proc-untrace-entry`
`proc-untrace-exit`
  These commands enable and disable tracing of entries into and exits from the `syscall` interface.
`info pidlist`
  For QNX Neutrino only, this command displays the list of all the processes and all the threads within each process.
`info meminfo`
  For QNX Neutrino only, this command displays the list of all mapinfos.