---
name: "errinfo"
section: "1m"
platform: "macos"
package: "dtrace"
version: "413"
release: "macOS 26.5"
platforms: ["macos"]
url: "https://new.carta.tech/errinfo"
---

# errinfo(1m)

print errno for syscall fails. Uses DTrace.

## NAME

errinfo - print errno for syscall fails. Uses DTrace.

## SYNOPSIS

**errinfo** \[-a\|-A\|-hsvZ\] \[-c command\]

## DESCRIPTION

errinfo snoops syscall failures and prints the errno value and description of the error number.

This program can help determine if applications are silently failing, providing some details on the cause.

Since this uses DTrace, only users with root privileges can run this command.

## OPTIONS

- \-c

  counts - print an aggregate style report containing a  frequency count of errors

- \-p PID

  examine this PID only

- \-n name

  examine processes with ths name only (eg, "ls")

## EXAMPLES

- Default output, print errors as they occur,

  \#  **errinfo**

- Print a frequency count report,

  \#  **errinfo** -c

- Snoop errors as they occur for "ssh" processes,

  \# **errinfo** -n ssh PP

- Snoop errors for PID 81 only,

  \# **errinfo** -p 81

## FIELDS

- EXEC

  Program name (truncated)

- SYSCALL

  System call name

- ERR

  Value of errno

- DESC

  Description of errno message

## DOCUMENTATION

See the DTraceToolkit for further documentation under the  Docs directory. The DTraceToolkit docs may include full worked examples with verbose descriptions explaining the output.

## EXIT

errinfo will run forever until Ctrl-C is hit.

## FILES

- /usr/include/sys/errno.h

  Contains the full descriptions for the error numbers.

## AUTHOR

Brendan Gregg \[Sydney, Australia\]

## SEE ALSO

dtrace(1M), [truss(1)](/truss/1.md)