PEEKFD(1) User Commands PEEKFD(1)

# [NAME](#NAME)

peekfd - peek at file descriptors of running processes

# [SYNOPSIS](#SYNOPSIS)

**peekfd** \[**-8**,**--eight-bit-clean**] \[**-n**,**--no-headers**] \[**-c**,**--follow**] \[**-d**,**--duplicates-removed**] \[**-V**,**--version**] \[**-h**,**--help**] *pid* \[*fd*] \[*fd*] ...

# [DESCRIPTION](#DESCRIPTION)

**peekfd** attaches to a running process and intercepts all reads and writes to file descriptors. You can specify the desired file descriptor numbers or dump all of them.

# [OPTIONS](#OPTIONS)

-8

Do no post-processing on the bytes being read or written.

[-n](#n)

Do not display headers indicating the source of the bytes dumped.

[-c](#c)

Also dump the requested file descriptor activity in any new child processes that are created.

[-d](#d)

Remove duplicate read/writes from the output. If you're looking at a tty with echo, you might want this.

[-v](#v)

Display a version string.

[-h](#h)

Display a help message.

# [FILES](#FILES)

**/proc/\*/fd**

Not used but useful for the user to look at to get good file descriptor numbers.

# [ENVIRONMENT](#ENVIRONMENT)

None.

# [DIAGNOSTICS](#DIAGNOSTICS)

The following diagnostics may be issued on stderr:

[**Error attaching to pid <PID>**](#Error)

An unknown error occurred while attempted to attach to a process, you may need to be root.

# [BUGS](#BUGS)

Probably lots. Don't be surprised if the process you are monitoring dies.

# [AUTHOR](#AUTHOR)

[Trent Waddington](mailto:trent.waddington@gmail.com)

# [SEE ALSO](#SEE_ALSO)

[**ttysnoop**(8)](/man/os/psmisc/ttysnoop.8)

2021-12-01 psmisc

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Document: peekfd(1) from psmisc 23.7-r7 (Chainguard OS)
Source: https://gitlab.com/psmisc/psmisc